renewable energy - the facts

P‘This is a great effort to present the facts on renewable energy to a broad audience – easily understandable, precise and visualized. Everybody who wants to get a quick overview of renewable technologies and good practices should read this highly informative book.’ProfEssor Dr PETEr HEnnickE, formEr PrEsiDEnT of THE WuPPErTal insTiTuTE for climaTE, EnvironmEnT anD EnErgy

‘This is a great summary of the debate and technologies of renewable energies, and fully up-to-date.’ProfEssor ErnsT von WEizsäckEr, co-cHair, uniTED naTions EnvironmEnT Program (unEP) rEsourcE PanEl

Interest in renewable energy has never been greater, but much uncertainty remains as to the role the various technologies will play in the transition to a low-carbon future. This book sets out the facts – how the technologies work, where and to what extent they are currently employed, and where the greatest potential lies. Covering all the major fields – solar electricity, solar thermal, solar architecture, bioenergy, wind, geothermal, hydropower, as well as new energy technologies – it also includes sections on how best to promote the uptake of renewables and answers to common questions and opposition. The authors provide a number of German-sourced yet internationally relevant examples and strategies that have become increasingly significant in the promotion of renewable energy in recent years. The convenient layout mixes detailed explanation with clear, take-away facts and messages on each double-page spread.

This straight-talking, information filled guide is the perfect primer for anyone who wants to better understand and promote renewable energy, whether in industry, study, policy or campaigns.

Dieter Seifried is director of Ö-quadrat, an independent consulting firm (www.oe2.de). He is the author of numerous studies and publications on energy policy and the energy sector and is currently a lecturer at the University of Freiburg for the ‘Renewable Energy Management’ Masters programme. Walter Witzel is Chairman of Baden-Württemberg’s Wind Energy Association.

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Energy / Environment

9 781849 711609

ISBN 978-1-84971-160-9

www.earthscan.co.uk www.energieagentur-freiburg.de

Earthscan strives to minimize its impact on the environment P Dieter Seifried and Walter Witzel

Renewable

EnErgy THE facTs

Renewable Energy – The Facts

3576 EARTHSCAN Renewable Energy 21/9/10 9:26 AM Page i

3576 EARTHSCAN Renewable Energy 21/9/10 9:26 AM Page ii

Renewable Energy –The Facts

Dieter Seifried and Walter Witzel

London • Washington, DC

3576 EARTHSCAN Renewable Energy 21/9/10 9:26 AM Page iii

First published in 2010 by Earthscan

Copyright © Energieagentur Regio Freiburg Gmbh 2010

Original German version published as: Walter Witzel and Dieter Seifried (2007) Das Solarbuch. Fakten,Argumente und Strategien für den Klimaschutz, 3rd edition, Ökobuch Verlag.

Published by Energieagentur Regio Freiburg, Freiburg/Germany [email protected]

The moral right of the authors have been asserted.

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted,in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except asexpressly permitted by law, without the prior, written permission of the publisher.

Earthscan Ltd, Dunstan House, 14a St Cross Street, London EC1N 8XA, UKEarthscan LLC, 1616 P Street, NW, Washington, DC 20036, USAEarthscan publishes in association with the International Institute for Environment and Development

For more information on Earthscan publications, see www.earthscan.co.uk or write [email protected]

ISBN: 978-1-84971-159-3 hardbackISBN: 978-1-84971-160-9 paperback

Typeset by FiSH Books, EnfieldCover design by Yvonne BoothTranslated by Petite Planète Translations

A catalogue record for this book is available from the British Library

Library of Congress Cataloging-in-Publication Data

Seifried, Dieter.Renewable energy : the facts / Dieter Seifried and Walter Witzel.

p. cm.Includes bibliographical references and index.ISBN 978-1-84971-159-3 (hardback) – ISBN 978-1-84971-160-9 (pbk.) 1. Renewable energy sources. I. Witzel, Walter. II Title.

TJ808.S54 2010333.79’4–dc22 2010020265

At Earthscan we strive to minimize our environmental impacts and carbon footprint through reducing waste,recycling and offsetting our CO2 emissions, including those created through publication of this book. For moredetails of our environmental policy, see www.earthscan.co.uk.

Printed and bound in the UK by CPI Antony Rowe. The paper used is FSC certified.

3576 EARTHSCAN Renewable Energy 21/9/10 9:26 AM Page iv

Contents

List of Figures 5Foreword by Rainer Griesshammer 8Preface 10New Paths to the Future by Luiz Ramalho 14

1 Introduction 161.1 Our climate is at stake 161.2 The inevitable fight for limited oil reserves 181.3 Addiction to energy imports 201.4 Nuclear energy is not an alternative 221.5 Renewables are the way of the future 241.6 We have enough sun 261.7 Scenario for the solar future 281.8 The solar strategy requires conservation 301.9 Cogeneration – an indispensable part of our energy transition 321.10 Liberalization of the German energy market 341.11 Economic benefits 38

2 Solar Thermal 402.1 Solar collectors 402.2 Hot water from the sun 422.3 Solar heating in district heating networks 442.4 Cooling with the sun 462.5 Solar drying – air collectors 482.6 Solar thermal power plants 50

3 Solar Electric: Photovoltaics 523.1 The heart of a PV array – the solar cell 523.2 Grid-connected PV arrays 543.3 Off-grid PV arrays 563.4 Solar energy as part of sustainable development 583.5 The outlook for PV – lower costs from new technologies and mass production 60

4 Solar Architecture 624.1 A third of the pie – space heating 624.2 Passive solar energy 644.3 The solar optimization of urban planning 664.4 Solar thermal and PV in renovation 684.5 The wall as a heater – transparent insulation 704.6 Homes without heaters – passive houses 72

3576 EARTHSCAN Renewable Energy 21/9/10 9:26 AM Page 1

4.7 The off-grid solar house – a model for the Solar Age? 744.8 Plus-energy houses 76

5 Biomass 785.1 Fields and forests as solar collectors 785.2 Biogas 805.3 Biogas cogeneration units 825.4 Wood as a source of energy 845.5 District heating networks with woodchip systems 865.6 Energy crops 885.7 Fuel from the field – biodiesel 905.8 Fuel from the plantation – ethanol 925.9 Synthetic fuels (BTL) 945.10 Is there enough land for biofuels? 96

6 Wind Power 986.1 Wind power comes of age 986.2 Wind power and nature conservation 1006.3 Wind velocity is key 1026.4 The success story of wind power since the 1990s 1046.5 The success story of wind power – the advantage of being first 1066.6 Wind power worldwide 1086.7 Wind power prospects – offshore turbines 1106.8 Wind power prospects – less is more through repowering 112

7 Water Power, Geothermal and Other Perspectives 1147.1 Water power – the largest source of renewable energy 1147.2 Expanding hydropower – the example of Germany 1167.3 Hydropower and nature conservation 1187.4 The world’s largest hydropower plants 1207.5 Geothermal worldwide 1227.6 Underground heat 1247.7 Hot dry rock – power from underground 1267.8 Other possible sources of renewable energy 128

8 New Energy Technologies 1308.1 Heat pumps 1308.2 Solar hydrogen 1328.3 How fuel cells work 1348.4 Stationary fuel cells 1368.5 Fuel cells in mobile applications 138

9 Current Use and Potential 1409.1 The potential in Germany 1409.2 The future has already begun in Germany 1429.3 EU votes for renewables 144

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9.4 Expanding renewables in the EU 1469.5 Renewables worldwide 1489.6 A long-term solar scenario for Germany 1509.7 The 100 per cent target 152

10 FAQs 15410.1 What do we do when the sun isn’t shining? 15410.2 How can we store large amounts of electricity? 15610.3 Can carbon emissions not be avoided less expensively? 15810.4 What is the energy payback? 16010.5 Are renewables job killers? 16210.6 Is the Solar Age the end of power monopolies? 164

11 Promoting Renewable Energy 16611.1 Research funding – not much money for the sun 16611.2 Start-up financing is needed 16811.3 Internalizing external costs 17011.4 Ecological taxation reform – protecting jobs and the environment 17211.5 Ecological taxation reform in increments 17411.6 Investment bonuses for solar thermal systems 17611.7 Solar energy in rental apartments – a problem child 17811.8 Compensation for solar power with a return on investment 18011.9 From the Feed-in Act to the Renewable Energy Act (EEG) 18211.10 The Renewable Energy Act (EEG) 18411.11 The EEG as a model for other countries 18611.12 Photovoltaic arrays as a ‘blight’ on the landscape 18811.13 Quotas and requests for proposals 19011.14 Solar thermal arrays required on new buildings 19211.15 Feed-in tariffs for heat in Germany? 19411.16 Emissions trading 19611.17 Clean Development Mechanism (CDM) 19811.18 A cornucopia of instruments 20011.19 Phasing out nuclear 20211.20 Renewable energy here and in the developing world 204

12 Good Marketing – Successful Projects 20612.1 Everyone loves the sun 20612.2 ‘Green electricity’ 20812.3 Not everyone owns the roof over their head – community solar arrays 21012.4 Solar brokers 21212.5 Service brings in new customers for all-in-one packages 21412.6 Investing in climate protection 21612.7 Utilizing new leeway 21812.8 Using new technologies 220

3

Contents


Notes 222Glossary 237Index 241

4



List of Figures

1.1 Our climate is at stake 171.2 Oil reserves: The gap between new discoveries and production widens 191.3 Global oil and gas reserves (2005) are restricted to a few regions 211.4 Nuclear power is not an option 231.5 The sun is the future 251.6 We have enough sun: The land needed for a 100 per cent solar energy supply 271.7 The Institute of Applied Ecology’s Energy Transition study (1980): Growth and

prosperity without oil and uranium 291.8 Solar strategy requires energy conservation 311.9 Cogeneration: An indispensible part of our energy tradition 331.10 Rising power prices: Profits at the expense of households and small consumers 351.11 The economic benefits of energy efficiency and renewables 392.1 Design of flat-plate collectors 412.2 Solar hot water 432.3 Solar thermal with long-term heat storage 452.4 Cooling with the sun 472.5 (1) Solar drying: How air collectors work 492.5 (2) Solar drying: Solar tunnel dryer for agricultural products 492.6 Solar thermal power plants 513.1 The heart of a photovoltaic array: The silicon solar cell 533.2 Grid-connected photovoltaic arrays 553.3 Off-grid photovoltaic arrays 573.4 A Cuban village school with solar power 593.5 Prospects for photovoltaics: Lower costs from new technologies and mass

production 614.1 Space heating: A comparison of key energy figures in various building standards 634.2 Passive solar energy: South-facing windows and roof overhangs instead of heaters

and air conditioners 654.3 Solar optimization of urban planning 674.4 Solar arrays as a component of renovation: Reducing energy consumption with

and without solar arrays 694.5 Walls as heaters: Transparent insulation 714.6 Homes without heaters: Passive houses 734.7 The Energy-Autonomous Solar House, Freiburg, Germany 754.8 Plus-energy homes 775.1 Forests and fields as solar collectors: The many ways of using biomass 795.2 Diagram of a biomass unit 815.3 Biogas cogeneration unit lowers CO2 by offsetting other CO2-intensive generation

sources 835.4 Getting energy from wood 85


5.5 District heating systems with woodchip heaters: A comparison on emissions 875.6 The potential energy yield of different energy crops in Germany 895.7 A comparison of alternative fuels and conventional systems 915.8 The energy payback of various fuels 935.9 How much a hectare can produce 955.10 Fuels from biomass take up a lot of land 976.1 Wind power takes off: The performance of wind turbines increases 996.2 Wind power and landscape conservation 1016.3 Wind velocity is crucial 1036.4 The success story of wind power: Trends in Germany since the 1990s 1056.5 The success story of wind power: The importance of being a first mover 1076.6 The installed capacity of wind turbines worldwide 1096.7 Tremendous potential for offshore wind 1116.8 Repowering: Less is more 1137.1 Water power: Global potential, used and untapped 1157.2 Hydropower in Germany 1177.3 Hydropower and nature conservation: Fish bypasses 1197.4 Giant hydropower: The Three Gorges Dam in China 1217.5 Geothermal: Installed capacity of a select group of countries 1237.6 Geothermal heat: How a hydro geothermal heat plant works 1257.7 Power from hard rock: How the hot-dry-rock method works 1277.8 (1) New power plant technologies: Solar chimneys 1297.8 (2) New power plant technologies: Seaflow 1298.1 Heat pumps 1318.2 Solar hydrogen 1338.3 How fuel cells work 1358.4 The efficiency of fuel cells for domestic power 1378.5 Mobile applications: Will hydrogen fuel cells help the climate? 1399.1 Technical potential of renewables in Germany and ecologically optimized

scenario 1419.2 Germany, the transition has begun: Power and heat from renewables 1439.3 The EU’s dependence on energy imports is growing 1459.4 Expanding renewables in Europe: Power generation in EU-15 1479.5 Renewables worldwide 1499.6 A long-term scenario for Germany: Renewables as a part of primary energy

consumption 1519.7 Bioenergy village of Jühnde: 100 per cent biomass 15310.1 What do you do when the sun isn’t shining? Annual solar and wind patterns 15510.2 How much energy can be stored? Energy storage with compressed air systems 15710.3 Can CO2 be offset less expensively in some other way? CO2 avoidance costs

(in euros per ton) 15910.4 Comparison of service life with energy payback 16110.5 85,000 wind power jobs 16310.6 The Solar Age: The end of power monopolies? The share of private power

generators as of 2004 in Germany 16511.1 Federal funding for energy research in Germany 167

6



11.2 Annual subsidies in the energy sector 16911.3 External costs of nuclear energy 17111.4 How ecological tax reform works 17311.5 Eco-taxes reduce start-up financing for renewable energy 17511.6 Upfront bonuses for solar thermal more effective than loans 17711.7 The problem child: Solar energy for tenants 17911.8 Feed-in rates for solar power get photovoltaics started in Germany 18111.9 From the Feed-in Act to the Renewable Energy Act 18311.10 The Renewable Energy Act: Feed-in rates for new systems connected to the grid

in 2007 18511.11 German feed-in rates abroad: Countries with feed-in rates for renewable

electricity 18711.12 Solar on disused land 18911.13 Quota systems and feed in rates: Which is more effective? 19111.14 The success of mandatory solar arrays in Barcelona 19311.15 Proposal for feed-in rates for Germany: Heat providers receive bonus for

environmental service 19511.16 How emissions trading works 19711.17 How the Clean Development Mechanism works: An example 19911.18 Using different policy instruments 20111.19 Phasing out nuclear 20311.20 Renewables for off-grid applications 20512.1 Public support for renewables 20712.2 Green power from utilities 20912.3 Community projects for solar power 21112.4 Solar brokers: The example of Zürich 21312.5 Service wins over new customers: All-in-one packages 21512.6 Climate protection as a good investment 21712.7 Renovation of Willibrord School as a community project: Carbon emissions were

reduced by 85 per cent 2005 21912.8 Solar lamps replace oil lamps: Benefits for people, environment and climate 221

7

List of Figures


There are dark clouds on the horizon.Climate change – long researched, discussedand denied – is increasingly making its pres-ence felt. Drawn up by more than 2000climate researchers from around the globe,the International Panel on Climate Change’s(IPCC) 2007 report has a clear message: theEarth will inevitably heat up by more than2°C above the temperature of the preindus-trial age. Additional warming would haveenormous consequences for mankind andthe environment, and a global economiccrisis can only be avoided if the globalcommunity works closely together.

‘The time for half measures is over’, formerFrench President Jacques Chirac once said,commenting on the challenges of climateprotection. ‘It is time for a revolution – anawareness revolution, an economic revolu-tion, and a revolution of political action.’

Unlike the three industrial revolutions (thefirst with the steam engine, loom and rail-ways; the second with crude oil, cars andchemistry; and the third with informationtechnology and biotechnology), the fourthindustrial revolution will have to be part andparcel of a transition to a solar economy –and it will have to be a global revolution.

Despite all the talk, global energy consump-tion continues to rise from one year to thenext. Industrial nations have only adoptedmodest climate protection policies, andenergy consumption is skyrocketing in themost populous developing nations of Chinaand India. We are called on to cut globalgreenhouse gas emissions in half by 2050; atthe same time, poor countries continue to

fight for their right to economic develop-ment. Therefore, our global switch to arenewable energy supply must be based ona dual strategy: greater energy efficiencyand the fast development of renewableenergy.

The dark clouds on the horizon do indeedhave a silver lining of sorts. Behind them is ablue sky and a shining sun. The fourth indus-trial revolution of efficiency and solar powerwill make our energy supply safer. No longerwill we fight for oil, and the battle againstpoverty will be won. Millions of new jobs willbe created, and national economies andconsumers will face less of a financialburden. The only thing to fear is inaction.

But the fear of inaction should be taken seri-ously. The main energy efficiencytechnologies and eco-efficient products –from cars that get 80 miles per gallon tocogeneration systems and homes thatproduce more energy than they consume –are already available. Seifried and Witzelshow a wide range of these convincingoptions in practice and discuss the politicalreasons for society’s reluctance to becomemore efficient.

In Renewable Energy – The Facts, theauthors concentrate on the second majorchallenge we face: covering all of our (dras-tically reduced) global energy consumptionwith renewables. They convincingly showthe great technical and economic potentialof solar energy alongside that of wind,water and biomass, each of which can beconsidered indirect solar energy.

Foreword


And that’s not all. They also show that anarrow focus on technical potential is near-sighted. The drastic structural change in ourenergy sector and society will only comeabout if society undergoes an innovationprocess. In addition to technologies, thisprocess requires the will to march on intosunnier days. It also requires proper institu-tional and market conditions – and differentconsumer behaviour, both in terms ofpurchases and product use.

The questions seem to be endless, but theanswers are provided in the book you holdin your hands. Renewable Energy – The Factsis a manual for the fourth industrial revolu-tion.

Rainer GriesshammerRainer Griesshammer is a member of theboard at the Institute of Applied Ecologyand a member of the German AdvisoryCouncil on Global Change.

9

Foreword


‘Renewables are the way of the future’ – 20years ago, this was a minority opinion. Backthen, our energy supply came from fossilsources (coal, oil and gas) and from nuclearpower. Power providers did not believe thatsolar energy could ever make up a largeshare of the pie and merely spoke of it as the‘spare tyre’, which was good to have onboard, but not something you would wantto rely on all the time.

Over the past few years, opinions havebegun to change. Markets for renewableenergy sources are booming around theworld. At the same time, the negativeeffects of our fossil-nuclear energy supplybecome clearer all the time:

• The dramatic impact on the climate ofour uninhibited consumption of fossilenergy is causing glaciers and polar iceto melt at rates previously unimagined.Ironically, the deserts are also expanding.Higher temperatures foster the spread ofmalaria and cholera, and extremeweather events, such as the Europeanheatwave in the summer of 2003 andHurricane Katrina in 2005, are becomingcommon. The warnings from researchersabout the catastrophic consequencesand the tremendous costs of climatechange are only becoming more urgent.For instance, in a study published inOctober 2006, Nicholas Stern, theformer chief economist at the WorldBank, argued that climate protection isthe best economic policy. While a lack ofeffective climate policies could causedamage amounting to up to 20 per centof global gross domestic product (GDP),

Stern calculated that proper climateprotection would only cost 1 per cent ofglobal GDP.1

• Crude oil and natural gas are becomingscarcer. Prices skyrocketed in 2008leading up to the economic crisis, whilethe war in Iraq was a reminder that mostof the world’s oil reserves are in anunstable part of the world.

• The reactor disaster in Chernobyl (1986)tragically demonstrated that there is nosuch thing as safe nuclear power.Indeed, mishaps continue to this day,such as in the summer of 2006 inForsmark, Sweden, and Biblis, Germany.Furthermore, we still do not know howto safely dispose of nuclear waste, whichis why we need to stop making it as soonas possible.

These and other reasons clearly illustratethat our fossil/nuclear energy supply is notsustainable and has no future. At the sametime, we are currently witnessing the begin-ning of the Solar Age and a boom inrenewables, though perhaps ‘witnessing’ isnot the right word – we are bringing thischange about ourselves. Obviously, solarpower is not a marginal player. Instead, it isthe only sustainable energy source we haveand will be a central pillar of our futureenergy economy alongside prudent energyconsumption.

The trends over the past few years leaveroom for no other conclusion; solar energy isno longer a marginal player.2 In 2006, thenumber of solar arrays installed in Germanycrossed the threshold of 1 million. In onlyseven years, from 1999 to 2005, the industry

Preface


increased its sales more than tenfold, equiva-lent to average annual growth of around 50per cent. In 2005, 45,000 people wereemployed in the solar sector, which posted€3.7 billion in revenue. By 2020, that figure isexpected to increase another sevenfold.

Wind power has grown even faster. Policiesin the 1990s got things going, bringingabout increasingly powerful wind turbines.For many years, Germany was the world’sleader in wind power and was only over-taken by the US in 2008. At the end of2008, Germany had installed a total capacityof 23,903 megawatts (MW) of wind power.The 20,301 wind turbines in the countrygenerated 40.4 terawatt-hours (TWh) ofwind power that year, equivalent to 7.5 percent of Germany’s power consumption. Thefigure from 2006, only two years earlier, was5.7 per cent; that year, wind power overtookhydropower as the biggest source of renew-able energy.

Nowadays, the payback from policies topromote wind power is clear. German firmsare global market leaders. Modern windturbines are being exported in largenumbers because in good locations windpower is cheaper than power from conven-tional central plants. At the end of 2007,some 90,000 people were employed in theGerman wind power sector.

Long overlooked, biomass recently moved tocentre stage. A number of communities heatnew buildings with renewable wood, andwood pellets ovens for detached homes andmulti-family units have become genuinecompetitors for oil and gas heaters. Withinjust three years, the number of these envi-ronmentally friendly boilers rose tenfold. Inaddition, a growing number of farmers arenow growing energy crops. Plantations ofrapeseed are a source of additional incomealongside biogas digesters.

All of these steps go in the right direction inour opinion, and they are all the results ofgovernment policy, such as Germany’sRenewable Energy Act (EEG). But Germanyis not a special case. A number of countrieshave adopted similar policies, called feed-intariffs (FITs). Some 60 countries worldwidehave adopted FITs, making it the leadingpolicy instrument to promote renewablesworldwide.

Wind power continues to boom worldwide(see www.ewea.org/fileadmin/ewea_docu-ments/documents/press_releases/2009/GWEC_Press_Release_-_tables_and_statis-tics_2008.pdf). For instance, in 2008,installed wind power capacity rose by some30 per cent, while the grid-connectedphotovoltaics (PV) capacity grew by morethan 70 per cent.3 Overall, a total investmentof €120 billion (2008) underscores thegrowing economic importance of the sector.

Crucially, China, the most populous countryin the world, has set some ambitious targetsfor itself. By 2020, renewables are to makeup 15 per cent of the country’s powerconsumption. In particular, China installedsome 13 gigawatts (GW) of wind capacity in2009 alone, bringing it more than halfwayto its target of 20GW by 2020 – and makingChina the global wind leader for that year.4

China also has ambitious plans for otherrenewable sources of energy, which all goesto show that renewables are a genuineoption for developing and newly industrial-ized countries.

Though the US did not ratify the KyotoProtocol, more than 300 mayors – fromChicago to New York, Los Angeles and NewOrleans – have stated their support for thetreaty.5 And though former President GeorgeW. Bush came from the oil sector and wassurrounded by consultants from the oilindustry, renewables boomed during his

11

Preface


administration more than ever before as thecountry worked to make itself less depend-ent on foreign energy imports.

Clearly, energy policy is in a transitionalperiod. Renewables are quickly becomingmore important. In this book, we navigateour readers through this process and providethem with facts and good reasons for thischange. We also present strategies for thequick transition to the Solar Age:

• The book first provides informationabout the many ways that solar energycan be used. We start with the direct useof solar energy: solar thermal and PV.The former creates heat; the latter, elec-tricity (Chapters 2–4). The sun is also theengine behind our climate; wind, cloudsand rain are the result of insolation.Likewise, plants (biomass) could not existwithout light. Biomass, wind power andhydropower are therefore thought of asindirect ways of using solar energy.Finally, geothermal is yet another renew-able source of energy (Chapters 5–7).We round off this presentation of energysources with an overview of new energytechnologies often mentioned in thecontext of renewable energy, such asfuel cells (Chapter 8).

• The second part of the book focuses onthe overall potential of solar energy. Wediscuss not only the possibilities ofvarious types of solar energy, but alsohow they are currently used in Germany,Europe and worldwide. A scenario forthe expansion of renewables illustratesour future prospects (Chapter 9). Anumber of arguments against the expan-sion of renewables are also repeatedlyvoiced in the debate about our futureenergy supply. In Chapter 10, werespond to some of the most commoncharges with some basic facts.

• The last two chapters concern how the

solar energy future we describe canbecome a reality. Chapter 11 provides anoverview and assessment of varioustypes of policies. Largely considered thebest policy, feed-in tariffs are the focalpoint. But the long-term expansion ofrenewables will have to include addi-tional instruments, such as for theheating sector. We also briefly presentthe history of the concept behind feed-intariffs, which go back to the AachenModel of ‘cost-covering compensation’.Finally, in Chapter 12 we present anumber of examples of creative market-ing strategies that have successfully spedup the implementation of renewableenergy (mainly in communities). In doingso, we hope to provide some ideas ofhow people and communities canbecome involved in addition to actionstaken by big energy players.

Renewable Energy – The Facts has a specialdesign: each page of text has a chart juxta-posed. The concept is intended to givereaders a quick overview of the topic. At thesame time, we as authors are forced to covereach issue on exactly one page. In somecases, some ancillary ideas had to be deletedand moved into footnotes. To facilitate read-ability, we have also added a glossary oftechnical terms. Interested readers will alsowant to consult the list of important publi-cations and websites to help them keep upwith current events and find additionalinformation on special topics.

This book is a translation of the third editionof the German publication; some of the datain the German book were updated for theEnglish publication.

We hope that you enjoy the English versionof this book and find that it provides youwith the basic knowledge you need to getinvolved in sustainable energy policy. There

12



may be many setbacks to come, but onething is also certain: the course of the suncannot be stopped.

Dieter Seifried and Walter WitzelFreiburg, March 2010

PS All the figures in this book can bedownloaded at www.earthscan.co.uk/onlineresources. We hope they prove usefulto you in your presentations and awareness-raising.

13

Preface


In the battle against climate change, practi-cal expertise in energy efficiency andrenewables is in higher demand than ever.After all, renewable energy represents a trulylong-term alternative compared to finite,environmentally unfriendly fossil energysources – which are also unsafe in terms ofsecurity. The inexhaustible power of the sunis not the only way to fulfil our responsibilityto future generations; wind, water andrenewable bioenergy are of help and can beused as well.

Renewables offer genuine hope for develop-ment because they can providedecentralized energy in developing coun-

tries; therefore, they are used whereverpoverty and a lack of energy would go hand-in-hand. They are also useful whereverpeople already have a lack of means to dealwith the consequences of the wrong energypolicy and environmental disasters such asdroughts, floods and hurricanes.

Renewable Energy – The Facts provides anumber of important answers to a lot ofsuch urgent questions. It offers the latestinformation and technical explanations,including interesting examples and how toput guidance into practice. An agency ofGerman development cooperation, InWEnt(Capacity Building International, Germany)

New Paths to the Future

Dear Readers,


supports this publication. The promotion ofrenewable energies and energy efficiency fordeveloping countries is at the core ofGermany’s policies to combat climatechange and to foster climate adaptation.

Climate and energy policy is not simply amatter for national governments. Politicians,even at the most local level, are alsoconcerned as are the private sector and indi-viduals. After all, energy consumption andclimate change make themselves felt in indi-vidual homes and businesses. Roughly 75per cent of energy consumption takes placein cities, which is why sustainable energypolicy has to be implemented there.Furthermore, the avoidance of carbon emis-sions and climate adjustments has to focuson urban areas. Worldwide, megacities andmetropolises have the greatest need foraction. These are the places where climatechange is caused – and where the changesare felt the most. In particular, the fast-growing Asian megacities are often locatedon rivers and coasts, where the rising sealevel caused by climate change is not anabstract idea but an everyday reality – alongwith increasingly frequent typhoons andfloods. The poor people in shanty towns

with the least money will pay the highestprice.

Cities are strong and flexible enough toimplement a new energy policy that will takethem in the right direction; national govern-ments, in contrast, often have sluggishgovernmental procedures, and resolutionstake time to be adopted. But thanks to theirclose contact with citizens and the privatesector, city governments are more able toraise awareness and implement innovativepolicies.

Renewable Energy – The Facts contains anumber of useful ideas easy to apply. It is amust-read for anyone who wants to actresponsibly and take advantage of theopportunities which the future offers.

Luiz RamalhoDirector of the Department of SustainableEconomy InWEnt

15

New Paths to the Future


1.1 Our climate is at stake

Climate change is already making itself felt.Over the last century, the average globaltemperature rose by 0.7°C. Glaciers in theAlps are retreating, as is the Arctic ice shelf.The frequency and strength of hurricaneshas increased, and extreme weather events –such as Hurricane Katrina in 2005 and theheatwave in Europe in 2003 – are becomingmore common.

The causes are well known. When fossilenergy is burned, carbon dioxide (CO2) isreleased. Its concentration is increasing inthe atmosphere, strengthening the green-house effect. Since the pre-industrial age,the concentration of CO2, the most impor-tant heat-trapping gas, has risen fromroughly 280 parts per million (ppm) to thecurrent level of almost 390ppm. But CO2 isnot the only heat-trapping gas emitted bycivilization. For example, large amounts ofmethane are released by farm animals and incoal and natural gas extraction. Likewise,laughing gas (nitrous oxide, N2O) is a heat-trapping gas from agricultural fertilizers.

These gases change the amount of energytrapped in the atmosphere and the amountreflected back into space. Shortwavesunlight penetrates the atmosphere and isreflected from the Earth’s surface. Reflectedwaves are generally longer and cannotpenetrate the atmosphere as well; heat-trap-ping gases partially absorb them. Thisnatural phenomenon (the greenhouseeffect) is vital for our planet; without thiseffect, the Earth would have an averagetemperature of –18°C. The increasingconcentration of these heat-trapping gasesis gradually disturbing this ecological equilib-

rium. Land and oceans are heating up faster,more water vapour evaporates from theseas, and hurricanes and typhoons arebecoming more common. The overallamount of energy input into the atmosphereis increasing. As a result, extreme weatherevents such as droughts, floods and heat-waves are becoming more common.

A decade ago, the idea that climate changewas man-made was still controversial, buttoday there is a widespread consensus:‘Nowadays, no serious scientific publicationdisputes the threat that emissions of green-house gases from the burning of fossil fuelsposes to the climate’, says Professor MojibLatif from the Leibniz Institute of MarineSciences at the University of Kiel, Germany.1

Nonetheless, there is still some resistance toefficient climate protection policy, thoughthis opposition is not the result of honestdoubts about climate change. Rather, someindustrial sectors simply have an eye on theirbottom line and are concerned that theirprofits may suffer, as some countries andlobby groups would have us believe.

1 1 Introduction


17

Introduction

1

Figure 1.1 Our climate is at stake

Source: Al Gore, An Inconvenient Truth, 2006; BMU

Concentration of carbon dioxide in the atmosphere*

Increase in the average temperature on the Earth

*Measured at the Mauna Loa Observatory

Annual average temperature in degrees Celsius

Individual values Linear trend


1.2 The inevitable fight forlimited oil reserves

At the beginning of the 1970s, the Club ofRome’s Limits to Growth raised awarenessabout the idea that exponential growth onEarth is not possible in the long term. It alsostated that crude oil reserves would bedepleted in 30 years under a specific set ofassumptions. Today, oil reserves are reportedto be 1200 billion barrels (a barrel contains159 litres), and the statistical range isreported as 42 years.2 Those may sound likereassuring figures, but they are not. Andthere are several reasons why.

Statistical range is an indication of howmany years current reserves – economicallyextractable oil using current technology andassuming that consumption remainsconstant – will last. But of course, if oilconsumption continues to increase as in thepast, then the statistical range will be muchshorter.

While new sources of oil were found regu-larly up to the beginning of the 1980s, nomajor discoveries were reported in the1990s. Since then, far more oil has beenconsumed than discovered (see Figure 1.2).

Our current oil fields cannot be drained atany rate we wish. Once an oil field has beentapped, it quickly reaches a point whereproduction cannot be increased. Once it hasbeen half emptied, one speaks of a ‘deple-tion midpoint’. After that, it is practicallyimpossible to speed up production. Andbecause most current oil fields have alreadyreached that midpoint, the productioncapacity of all oil fields in the world willbegin to fall sooner or later – even thoughthe range may statistically hold out for a fewmore decades. A number of oil-producingcountries – such as the US, Mexico, Norway,

Egypt, Venezuela, Oman and the UK – havealready passed their production peak, andothers are soon to follow. A number ofexperts are therefore talking about peak oilproduction for the world – called ‘peak oil’ –which some say may have already beenreached or may happen soon.3 Whenproduction is likely to decrease as demandincreases, prices can be expected toskyrocket, as indeed they did before therecent economic crisis.

One more crucial factor has to be kept inmind: the remaining oil reserves are largelyfound in a small number of countries. In2005, OPEC members had three quarters ofall proven reserves. Indeed, five countries ofthe volatile region of the Persian Gulf –Saudi Arabia, Iraq, Kuwait, the United ArabEmirates and Iran – alone make up 60 percent of global oil reserves.4 Instability there-fore not only results from the absolutescarcity of oil reserves, but also from unequaldistribution.

An energy policy based on renewables andenergy efficiency will therefore not onlyprotect the climate, but also make us lessdependent on fossil energy, thereby reduc-ing the potential for armed conflict overscarce reserves and resources.

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1

Figure 1.2 Oil reserves: The gap between new discoveries and production widens

Source: BP, IEA, Aspo, taken from SZ Wissen 1/2005

New discoveries per year

Billions of barrels of oil

Oil production


1.3 Addiction to energy imports

Though Germany is sometimes touted as aglobal leader in renewables, the countryimported 59 per cent of its primary energyconsumption as oil or gas in 2005. And evenwhen it comes to nuclear energy (12.5 percent of primary energy consumption) andhard coal (12.9 per cent), Germany is hardlyindependent; 100 per cent of its nuclear fuelrods are imported, and more than 50 percent of the coal burned in Germany comesfrom abroad.

The situation overall in the European Union(EU) is hardly better. The 25 member statescurrently import around half of their energy.If consumption and domestic productionwere to continue in line with the currenttrend, the share of imports would soonexceed two thirds. Domestic productioncontinues to drop within Europe, but energyconsumption is increasing considerably. As aresult, the share of domestic energy willcontinue to drop if energy policy fails tochange these trends.

Rising prices on the global crude oil marketwoke up energy politicians both in Germanyand the EU a few years ago. In the autumnof 2005, oil prices began to skyrocket,reaching prices that surprised many; a barrelof crude oil (159 litres) was being sold formore than US$70. But even that price woulddouble before the economic crisis suddenlybrought prices back down. The effects ofthis price hike made themselves felt inconsumer prices. While a family thatconsumes 3000 litres of heating oil a yearonly had to pay around €1000 in Germany in2003, that figure had doubled by2005/2006 and would double again by2008.

Oil and gas imports to Germany rose to €66billion in 2005, a 27 per cent increase overthe previous year.5

Dependence upon energy imports not onlymeans a heavy outflow of capital, but alsonarrows political leeway6 and, as we haveseen over the past few years, increases thelikelihood of armed combat over scarceresources.

Sustainable energy policy based on energyefficiency and renewables thereforestrengthens local markets by redirectingcapital that would have left the area to payfor energy imports into domestic energysources. But such a policy also helps keepthe peace by making battles for scarceresources unnecessary to begin with.

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1

Figure 1.3 Global oil and gas reserves (2005) are restricted to a few regions

Source: BP Statistical Review 2006

47.820

9,900

1,570

13,60015,500

3,1706,900

36,100

700 1,100

6,04013,000

26,74018,200

3101,500

2,3502,300 5,100

1.490

5,2304,800

4,32011,000

2,4101,300

5,4503,600

1,5902,400

Oil in millions of tons

Gas in billions of cubic metres

Canada

USA

Brazil

Venezuela

Nigeria

Iraq Kuwait SaudiArabia

UnitedArab

Emirates

India

China

Russia

Iran

Libya

Norway

Roughly 60 per cent of global oil reserves is located in a few countries in thenear East: Saudi Arabia, Iran, Iraq, Kuwait and the United Arab Emirates.


1.4 Nuclear energy is not analternative

A number of issues pertaining to nuclearenergy have yet to be resolved and may beirresolvable:7

• The danger of a reactor meltdown likethe one in Chernobyl (1986) remains, asevents in July 2006 at Sweden’sForsmark nuclear plant revealed.8

• There is still no final repository for highlyradioactive waste.

• The ‘peaceful’ use of nuclear energycannot be completely separated frommilitary applications.

• There is no perfect way to protectnuclear plants from terrorist attacks.

Germany, therefore, recently resolved tophase out its nuclear plants.9 In 2005, theObrigheim plant was the first to be decom-missioned. Since then, nuclear plantoperators have been attempting to overturnthe agreement they themselves signed inorder to have longer commissions for theirnuclear plants. They have discovered a newargument: climate protection. They claimthat nuclear power would have to bereplaced by coal plants and gas turbines,which produce more CO2 emissions thannuclear plants, thereby running contrary tocurrent efforts to reduce these emissions.

Nonetheless, longer commissions for nuclearplants are the wrong way to get out of ourclimate trap, as would be newly constructednuclear power plants. For instance, if wewant to use nuclear power to ensure thatwe reach the German goal of an 80 per centreduction in CO2 emissions below the levelof 1990 by 2050, Germany would have toconstruct and operate some 60–80 newnuclear plants, roughly 4–5 times more thanthe current 17 nuclear plants in Germany.10

Globally, several hundred new nuclear plantswould need to go on line to reduce CO2

emissions considerably; some 440 arecurrently in operation. In turn, nuclear riskswould increase significantly.

At the same time, the supply of nuclear fuelrods is hardly ensured. At current rates ofconsumption, uranium reserves will only lastfor another 40–65 years.11 If we build newnuclear plants, the uranium would not evenlast that long.

In addition, investments made in the energysector clearly revealed that nuclear power isnow considered too expensive. Since thedisaster at Chernobyl, very few new nuclearplants have been ordered, and the ones thatwere built generally received generous subsi-dies.12

The nuclear industry would have us believethat nuclear power is undergoing a renais-sance. Lobbyists like to point out that a fewplants are currently under construction, butthose figures include discontinued projectsabandoned years ago. And because so manynuclear plants will be decommissioned overthe next few years worldwide even underthe normal schedule, the number of nuclearplants will decrease.13

At the beginning of 2007, for example,seven nuclear plants in Europe were takenoff the grid for good – four of them in theUK, two in Bulgaria and one in Slovakia.14

The risks of nuclear power can be preventedif we switch to renewables, which are anenvironmentally friendly alternative (see11.18).

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1

Figure 1.4 Nuclear power is not an option

Source: IAEA

Number of reactors in operation worldwide

Over the next decade, the number of nuclear power plants in operation willdrop, as will the amount of nuclear power produced.


1.5 Renewables are the way ofthe future

While the share of renewables in Germanyhas been increasing drastically over the pastten years, the country still gets around 85per cent of its energy from fossil sources. Oilmakes up the largest share of the pie at 36per cent, followed by coal at 24 per cent andgas at 23 per cent.15

Up until the 18th century, civilization got all ofits energy from such renewable sources aswood, wind, water and muscle. Coal – andlater oil and gas – only took off at the begin-ning of industrialization. Today, we admittedlydo not face any acute shortage of fossilenergy, but reserves are nonetheless finite.Estimates are that, under current consump-tion, known reserves of oil will be depleted insome 40 years and brown coal in 220 years.16

And while new resources may yet be discov-ered, these resources remain finite. Figure 1.5clearly shows that the age of fossil energy willonly appear as a blip on the screen of energyconsumption over a 4000 year period.

When coal, oil and gas are combusted, CO2

is released. CO2 is the main reason why theEarth’s atmosphere is heating up – and whythe climate is in danger. Back in 1990, theGerman Parliament’s Commission onProtecting the Earth therefore called for an80 per cent reduction in CO2 emissionswithin Germany by 2050.

Nuclear power currently covers some 30 percent of electricity consumption in Germany,roughly 13 per cent of the country’s totalenergy consumption. However, the risk of amajor reactor meltdown like the one inChernobyl in 1986 and the unsolvedproblem of waste disposal rules out thishigh-risk technology as part of a sustainableenergy supply.

So we are left with one major source ofenergy over the long term: the sun.17 It canbe used both to generate heat and electric-ity (solar thermal and solar power). At thesame time, however, the sun is also thereason plants (biomass) grow and theweather changes. Different amounts ofsunlight hit the Earth’s surface in differentlocations, bringing about wind.18 And whenthe sun shines, ocean water evaporates,creating clouds and rain – hydropower.Biomass, wind power and hydropower aretherefore indirect ways of using solar energy.And because the sun, wind, water andbiomass are inexhaustible in human terms,they are called ‘renewable’ types of energy.

There are a number of ways to use solarenergy directly and indirectly, and all of themare constantly being further developed.Along with greater efficiency in energyconsumption (see 1.8), indirect and directsolar energy will provide a reliable, sustain-able energy supply.

Renewables are the way of the future. TheSolar Age will arrive one way or the other.The question is only whether we willmanage that transition without crises andmajor conflicts.

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1

Figure 1.5 The sun is the future

Source: Goetzberger and Wittwer, Sonnenergie; Bundesamt für Geowissenschaften und Rohstoffe, 2006

Global fossil energyconsumption

1st Solar Age 2nd Solar Age

Greek antiquity

Date (Year)

Range of fossil energy sources

Hard coal ˜150 yearsBrown coal ˜220 yearsNatural gas ˜63 yearsPetroleum ˜40 years


1.6 We have enough sun

The sun is our planet’s main source ofenergy. Each year, the sun provides the Earthwith 7000 times our current global energyconsumption – a figure that does not varymuch. Although roughly 70 per cent of thatenergy falls onto the ocean, there is stillenough solar energy left. For instance, anarea of the Sahara 200km by 200km –roughly the size of Kentucky or twice thesize of Wales – would suffice to covercurrent global energy consumption. Buteven if this sunlight could only be used at anefficiency of 10 per cent, we would still onlyneed an area roughly 700km by 700km tocover our current global energy demandwith solar power.19

Of course, the sun only reaches Germany athalf the strength of sunlight in the Sahara –roughly 1000–1100kWh per square metre,equivalent to the amount of energy inapproximately 100 litres of heating oil. Inother words, the sun pours roughly theenergy equivalent of 100 litres of oil on eachsquare metre of Germany each year in theform of sunlight. Overall, Germany receivesmore than 80 times more solar energy thanit currently consumes from all energysources.

Sunlight comes in two varieties: direct anddiffuse. The latter occurs when sunlight isreflected, such as in clouds. The light thenreaches the surface from various directions.Some solar energy systems need directsunlight (see 2.6), but most can utilize bothdirect and diffuse sunlight.

These figures clearly show:

1 Insolation, even in northern Europe, isstill roughly half as strong as in thetropics and subtropics. It thereforemakes sense to use solar energy even atsuch latitudes. While the solar yield isthen lower, there are no transport costs.

2 Even in an industrial country such asGermany, the sun still provides severaltimes the energy needed.

The benefits of solar energy are clear, butlow ‘energy density’ is a crucial drawback.While 1000W of solar power may reach asquare metre of northern Europe under fullsunlight, the annual average is only around100W per square metre. Large areas aretherefore required for solar arrays. But if welimit ourselves to available roof space, wesee that Germany has some 3500km2,approximately 800km2 of which could beused for solar energy.20 With current tech-nology, Germany could therefore get some16 per cent of its current power consump-tion from solar on such roofs – and muchmore if power is used more efficiently. Inaddition, facades, bridges, noise barriers,etc. are also available. And then we havewind power, hydropower and biomass toround off our future renewable solar energysupply.

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Introduction

1

Figure 1.6 We have enough sun: The land needed for a 100 per cent solar energy supply

Source: The authors

The land needed to coverour current global energyconsumption with solarpower (10 per centefficiency)

700 km

700 km


1.7. Scenario for the solar future

If we are to change our economy so that wecan get most, and possibly all, of our energyfrom the sun and other renewables, weneed to change our energy policy first. Backin 1980, the Institute of Applied Ecology inFreiburg, Germany, worked up a scenario forthis transition.21 The main thing that we haveto change is our minds: the focus does notneed to be on greater energy consumption,but on greater prosperity. Entitled‘Energiewende’ (Energy Transition), theInstitute’s study therefore took a look atsociety’s needs for energy services, such aslighting, transportation and heated build-ings. The energy required for these tasks notonly depends upon the scope of these serv-ices, but also on energy efficiency. If, forinstance, gas mileage can be tripled, peoplecould then drive three times as far with thesame amount of energy – or 50 per centfurther with half as much fuel. The studydemonstrated such efficiency potential in anumber of fields. It concludes that we canreduce our primary energy consumption bynearly 50 per cent over the next 40–50 yearseven as our standard of living continues toincrease.

These findings have been confirmed againand again since:

• The 11th German Parliament’sCommission on Protecting the Earth’sAtmosphere found that energy savingsof 35–40 per cent are feasible.22

• In Factor Four,23 Ulrich von Weizsäcker,Amory Lovins and Hunter Lovins tell theClub of Rome that the efficiency gainsare so great that standards of livingcould be doubled even as energyconsumption is cut in half.

• Another study in Germany, entitled ‘LeadStudy 2007 – Update and reassessmentof the use of renewable energies inGermany’ showed the potential andcosts of this transition.24

In addition to demonstrating the greatsavings potential, the Energy Transitionstudy conducted by the Institute of AppliedEcology also includes a scenario for the solarfuture. For example, solar energy canprovide low-temperature heat. A greatershare of wind and hydropower would coverour electricity consumption. Waste from thetimber and agricultural sectors wouldprovide heat, electricity and motor fuels. Ifthe conservation potential is fully exploited,our energy supply could be redesigned sothat solar, wind, hydropower and biomasscover roughly half of our energy consump-tion by 2030. The other half would thenmainly come from coal in highly efficient,and therefore environmentally friendly,cogeneration plants.

The Energy Transition study does not specif-ically talk about a solar economy as a goal,but it does emphasize three important stepson the path towards a solar economy:

1 Conservation should be exploited when-ever possible.

2 Cogeneration should be used as a bridgetechnology.

3 Renewables must be expanded.

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1

Figure 1.7 The Institute of Applied Ecology’s Energy Transaction study (1980): Growth andprosperity without oil and uranium

Source: The authors

Millions of tons of hard coal equivalent

Windandwater

Solar Biomass

NaturalgasOil

Coal

Energy transition means:

• Consistently tapping conservation potential• Using cogeneration• Expanding renewables


1.8 The solar strategy requiresconservation

Let us now focus on the three examples ofenergy conservation and energy efficiencyfor the solar strategy explained in the previ-ous section.

Example 1: Standby powerconsumptionIn Germany, electrical appliances in officesand homes consume some 22 billion kilo-watt-hours of electricity each year,25 roughlythe amount generated by four nuclearpower plants. If this electricity had to beprovided by solar panels, more than 200km2

would be needed. In light of the costs andmaterials required, the effort would beabsurd, especially when we realize that thisstandby consumption could already bereduced by more than 80 per cent today ifwe replaced our current appliances withnewer ones that consume less standbypower. The Eco-design Directive for Energy-using Products (2005/32/EC) was adopted in2005 and came into force in August 2007. Itestablishes a framework under which manu-facturers of energy-using products (EuP) will,at the design stage, be obliged to reduce theenergy consumption and other negativeenvironmental impacts that occur during theproduct’s life cycle. From the beginning of2010, the ‘off mode’ electricity consumptionof all appliances sold in Europe is notallowed to exceed 1W and the stand-bymode is limited to 2W.

And if we switch appliances off completely(i.e., do without standby mode), we canreduce our consumption even further.

Example 2: Space heatingThe average German single-family detachedhouse with 120m2 of floor space consumessome 30,000kWh per year for heating andhot water. A large solar hot water system

(12m2) can produce some 13 per cent of theenergy required for that task. To increase thatshare considerably, consumption has to bereduced by means of good insulation and effi-cient windows. Such ‘low-energy buildings’(see 4.1) make do with around 10,600kWhper year. But a 12m2 solar thermal array wouldthen cover 28 per cent of peak demand (seeFigure 1.8). The greater the efficiency, thegreater the share of solar energy.26

Example 3: Efficient pumpsMore efficient pumps and pump controlswould save many billions of kilowatt-hoursof electricity and heat in homes, businessesand industrial plants. But this change wouldrequire decision-makers to be betterinformed and tradespeople better trained; inaddition, we would need an investmentphilosophy that accepts higher investmentcosts in return for lower operating costs.27

These three examples make it clear that asolar energy supply is easier to reach and lessexpensive if conservation measures aresimultaneously exploited.

Towards the goal of 100 per cent solarenergy, Example 2 does not seem thatconvincing. If we want to go further, we cando the following:

• Use more solar energy. A larger solararray would cover a larger share ofheating demand (see 2.3).

• Use greater efficiency. By further improv-ing insulation and ventilation systems,we can do without heaters altogether(see 4.6).

• Use other types of renewable energy. Acombination of solar collectors andwood heating can provide renewableheat all year round (see 4.8 and 5.4).

These options represent a good startingpoint for the transition to the Solar Age.

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Figure 1.8 Solar strategy requires energy conservation

Source: The authors

Normal house(poor energy efficiency)

Low energy house(great energy efficiency)

Energyconsumptionper year

31,000kWh

Solar share

Energyconsumptionper year

10,6600kWh

Solar share

13 per cent of energy requirementsmet by a 12m2 solar array

28 per cent of energy requirementsmet by a 12m2 solar array

Solar share (per cent) of total house energy demand

Greater efficiency helps increase the share of solar:

13%

28%

10,660kWh31,000kWh


1.9 Cogeneration – anindispensable part of ourenergy transition

Today, the generation of electricity is thecause of more than a third of all carbonemissions in Germany. The reason is the lowefficiency at which power plants convertfuels into power. On average, fossil powerplants run at efficiencies far below 40 percent. If we then deduct the power neededby the plant itself and transport losses on thegrid, we see that only a third of the primaryenergy fed into the plant actually arrives atyour wall socket.28

The alternative to conventional powergeneration is called cogeneration. Here,waste heat from the power generationprocess in conventional steam turbines isused. For the waste heat to be used in resi-dential areas, hospitals or commercial units,the power has to be generated close toconsumers.

The overall efficiency of cogeneration unitsranges from 85–95 per cent.

Because of this high rate of efficiency,cogeneration units are not only much betterecologically, but also economically.Nonetheless, cogeneration plants make upless than 10 per cent of installed capacity inGermany because large utilities have consis-tently attempted to stamp out cogenerationefforts by communities and industry, whichwould have cut into the sales revenue of util-ities.29

The liberalization of the power market madethe efforts to stamp out cogeneration evenfiercer. Large power producers, all of whomsuffered from overcapacity, lowered theirprices to cutthroat rates so that the alreadyinstalled fleet of cogeneration units was no

longer profitable. With prices at 2–3 euro-cents per kilowatt-hour – below the cost ofproduction – even highly efficient cogenera-tion cannot compete.

To take account of the negative effects ofliberalization on cogeneration, Germanypassed its Cogeneration Act in March 2002.The goal was to reduce carbon emissions by23 million tons annually by 2010 throughcogeneration. In all likelihood, this targetwill not be reached. One of the goals of thenew governing coalition in Germany istherefore to respond to calls by the cogener-ation sector and improve legislation.30 TheUK has also come up with some proposalsfor proper compensation of heat in itsEnergy Bill.

We need only look elsewhere in Europe tosee how effectively cogeneration can beused. In Denmark, Finland and TheNetherlands, the share of cogeneration inpower production is between 40–50 percent.31

For the next few decades, we will still havefossil power plants generating electricity. It istherefore crucial that we use these powerplants as efficiently as possible in order toreduce the environmental impact. Likeenergy conservation, cogeneration is there-fore a crucial part of our transition to theSolar Age.

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Figure 1.9 Cogeneration: An indispensable part of our energy tradition

Source: The authors

Separate generation

Fuel input

Power plant Heating system

LossesLosses

Energy madeavailable

Heat

HeatElec-tricity

Fuel input

Cogeneration

Energy madeavailable

Losses

Separate generation (cogeneration)

Cogeneration reduces primary energy consumption by around 40 per cent


1.10 Liberalization of theGerman energy market

On 29 April 1998, the German energymarket was ‘liberalized’. From one day tothe next, former monopoly power providerssaw their markets opened up to the compe-tition; after 60 years of monopoly service,customers could now (temporarily) lookforward to competition. They could choosetheir own power provider.

The effects of liberalization were drastic.Power prices initially fell, providers mergedand the big fish acquired the small fish.Power providers have increasingly focused onwhat they see as their core business: increas-ing sales revenue. In particular, overcapacityand predatory pricing put more and morepressure on community cogeneration plants,some of which were decommissioned.Drawn up at the beginning and middle of the1990s, least cost planning schemes32 toincrease the efficiency of electricity consump-tion were put on ice or discontinued.

Competition temporarily made it cheaper forfamilies to consume electricity. Initially,experts expected retail rates to remain basi-cally stable in the wake of liberalization, butsomething surprising happened in the fall of1999, when RWE and EnBW – two ofGermany’s Big Four power providers – begancutting prices to gain market share. Only afew years later, the battle for a larger shareof the retail market died down. Indeed, retailrates are currently much higher than theywere before liberalization and continue torise far faster than inflation.33

From 2002–2007, for example, retail ratesrose by around a third without any increasein taxes on power.34 The main reason forthese price hikes is the market power of theBig Four and the lack of competition. After abrief phase of fierce competition (1998 to

2000), E.ON, EnBW, RWE and Vattenfallrealized that the best strategy was to divideup the pie among themselves rather thancompete for a bigger slice. Their strategy isworking quite well; after all, the four oligop-olists run 96 per cent of all baseload plantsand account for 80 per cent of all powergenerated in Germany.35

In 2005, politicians responded to increasingpower prices and the lack of competition bycreating the German Federal NetworkAgency. The Agency has already succeededin lowering excessively high power transitfees in a number of cases. But even theAgency can only go so far in creating truecompetition between companies. AloisRhiel, Economics Minister in the State ofHessen, thus called for antitrust law to bemade stricter in order to demonstrate thatthe government can make a difference. Ashe put it: ‘Otherwise, the state will have todo away with the oligopoly of powerproducers and force the Big Four to sellpower plants.’ His goal was to increase thenumber of power producers until competi-tion could get a foothold, the goal being toreduce retail rates. He argued that highpower prices were bringing down theGerman economy.36

In October 2006, the German governmenttook another step to ensure competition bymaking it easier for retail customers to switchpower and gas providers. Now, customersneed only give one month’s notice.

At this point, it is up to customers todemand competition. Unfortunately, theyhave been reluctant to do so up to now.From 1998 (the beginning of liberalization)to the end of 2006, fewer than 5 per cent ofhousehold customers switched powerproviders even though they could havesaved a lot of money by moving to aprovider with lower rates.37

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1

Figure 1.10 Rising power prices: Profits at the expense of households and small consumers

Source: The authors

Profits in billions of euros

Profits of the Big Four (E.on, RW E., Vattenfall and EnBW)

Retail electricity rate in Germany (average annual consumptionof 3,500 kWh)

Power price in cents/kWh


The changing market has also endangeredmunicipal power companies. A number ofthem have responded proactively out of fearof competition and sold shares to the BigFour. In doing so, they generally also soldtheir leeway to design community energypolicy. Experience has shown that the busi-ness and sales interests of the Big Four thentake precedent, even if they only hold aminority of shares in the municipals.

Yet, the prospects for municipal energyservice providers are quite good.38 On theone hand, they can pick and choose a powerprovider; on the other, they know theircustomers well and have the expertise tooffer the kinds of energy services in demand.But they will only be able to justify their exis-tence if their services differ from the onesoffered by firms motivated solely by profits.

The next few years will show whether munic-ipal utilities will succeed even if their pricesare not the lowest provided if they offer theenergy services customers demand.39

One of those services is a commitment torenewables. But merely providing ‘greenpower’ is not enough; rather, municipal util-ities should help construct and financesystems owned by their customers andpromote community projects.

Two main pillars of the energy transitionhave been crippled by the liberalization ofenergy markets:

1 Power generation in municipal cogener-ation units and industry has beenramped down. Because the Big Fourhave used their overcapacity to pursuepredatory pricing, cogeneration nolonger pays for itself. The Germangovernment reacted to the inevitablewith a special law to promote cogenera-tion, but the goal of reducing emissions

by 23 million tons of CO2 by 2010 willnot be reached under current legislation.

Improved legislation is thereforeneeded quickly; after all, an energysupply based on solar energy cannot dowithout efficient power plant capacity,exactly what cogeneration provides.Indeed, cogeneration plants can not onlyhelp cover the baseload, but alsocompensate for fluctuations in intermit-tent renewable power (see 10.1).

2 Since the beginning of liberalization, theBig Four have focused even more onsales of kilowatt-hours. Yet, whatcustomers need is inexpensive energyservices. After some success stories inthe mid-1990s, energy conservationcampaigns have become rare amongutilities. And while customers benefitedfrom lower power prices initially, todaythey can only defend themselves byswitching providers, which they largelyfail to do.40

Our experience with liberalization demon-strates that the market has to be changed ifthe environment and the climate are to beprotected. The market needs guidelines so itwill develop in the desired direction. If thesechanges are not made, liberalization willhave a tremendous environmental impactand be a tremendous burden on the Germaneconomy. So where do we go from here?

• Our tax system has to be systematicallyredesigned to increase the tax burden onenergy consumption and resourceconsumption and lessen the burden onlabour. What we need is the kind of envi-ronmental tax reform that Germanybegan ten years ago with its ‘eco-tax’ onfossil fuels. But the current tax rates onenergy consumption and private homes,businesses and industrial plants are notyet high enough to ensure that energy is

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consumed efficiently. Further steps arenecessary.41

• We need a tradable quota for cogenera-tion. Utilities should be required to covera certain share of the power they sellwith cogeneration units. The utilitiescould then decide whether they want togenerate that power themselves orpurchase it. Current German law, basedon a floor price (feed-in tariff) for kilo-watts of electricity exported to the grid,cannot ensure the success of cogenera-tion as well.

• A special fund42 for energy conservationand/or energy efficiency should becreated, and further steps should betaken to promote efficient technologies(demonstration projects, trainingprogrammes, better labelling on largeelectronic devices, energy ratings forbuildings, stricter efficiency standards,etc.). An energy efficiency fund wouldpublish competitive requests for energyconservation proposals. The companythat can provide the required energyconservation at the lowest cost would beawarded the contract. Such energy effi-ciency funds have already provensuccessful in a number of countries.43 Theefficiency fund could be financed bymeans of a surcharge on the retail elec-tricity rate or on the other energy carriers.

• Stricter energy conservation require-ments for new buildings and renovationprojects.

• Utilities must be forced to compete forcustomers to a greater extent so thatutilities will change the services theyoffer. The price per kilowatt-hour shouldnot be the only reason to switch utilities.Rather, customers should also take othereconomic, ecological and social aspectsinto account. To this end, the perform-ance of utilities should be rated. Suchratings would provide benefits not onlyto customers, but also to companies

with an eye on long-term success.44

• New regulations are needed to allowgrid operators to pass on the cost ofinvestments in energy conservationcampaigns to their customers, whichthey are currently not able to do.

• Renewable energy sources shouldreceive assistance for market launch, andfeed-in tariffs must be offered for renew-able power exported to the grid. This iswhere governments can make the great-est difference (see 11.9–11.12).

• Nuclear power has to be phased out asquickly as possible (see 1.4 and 11.18)and energy policy has to be restructuredaccordingly. Here, it is crucial that the EU,member states and regional govern-ments state specific targets and pursue areliable energy and transport policy toprovide a stable business environment forinvestors, manufacturers of efficiencytechnology and producers of renewablestechnology over the long term. A numberof new market players will be required inthe process: energy agencies, contractingfirms,45 and academic centres that offerdegrees in energy. Companies focusingon efficiency technology could step upenergy and electricity conservation.These firms will, however, only besuccessful if the business environmentfosters the kind of work they do.

Clear signals set by reliable taxation andincentives for consumers are equally impor-tant. Indeed, they are indispensable ifconsumers are to take energy costs intogreater consideration when purchasingitems with long service lives, such as carsand refrigerators.

We already know that a sustainable energysupply is not a pipe dream, but a feasiblealternative.46 It is also affordable and wouldprovide significant economic and socialbenefits.

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1


1.11 Economic benefits

Considerable investments will have to bemade for our energy supply system tobecome sustainable; renewables will have tomake up a large share of our supply, andenergy applications will have to becomemuch more efficient. These upfront invest-ments are offset over the long term by lowerenergy costs and independence from fossilenergy sources, which are only going tobecome more expensive.

At current oil and gas prices, a wide range ofinvestments in energy efficiency already payfor themselves and provide both macro andmicroeconomic benefits without any subsi-dies.47 In contrast, renewable energy sourcesrequire further support, such as from feed-intariffs, which ensure a return on investmentsin renewables (see 11.10). But thesurcharges that feed-in tariffs entail do notsimply increase the price of electricity forconsumers; rather, the growing share ofrenewable energy sources has broughtpower prices down on power exchanges, asrecent independent studies have demon-strated.48 While this may seem surprising atfirst glance, it makes complete sense. Priceson power exchanges are sorted in ascendingorder. The greater the demand for power,the more power plants with low efficiencyrates and higher fuel costs are used. But if alarge amount of renewable power is beinggenerated, the worst power plants are nolonger used. Supply and demand convergeto produce lower exchange prices. Onaverage, power prices in Germany havefallen as a result by as much as 0.76 euro-cents per kilowatt-hour.49

In particular, such macroeconomic benefitsare the main reason why we should restruc-ture our energy supply:

• External costs in our current energysupply – from air pollution, climatechange, the risk of nuclear disaster andthe cost of securing access to raw mate-rials – are by definition not included inmonthly power bills. Instead, they areincurred outside of our energy supply asexternal costs that society must cover. Asustainable energy supply largely avoidssuch external costs. Furthermore, there isthe increasing damage caused byextreme weather. These costs have risento nearly €2 billion per year on averagefor Germany alone, but the GermanInstitute for Economic Research (DIW)estimates that that figure could rise to€27 billion by 2050.50

• A sustainable energy supply wouldcreate hundreds of thousands of jobs. Inthe renewables sector alone, 280,000new jobs had been created by 2008 inGermany, and that figure could rise to500,000 by 2020 (see http://bee-ev.de/Energieversorgung/Wirtschaftlichkeit/Arbeitsplaetze.php). Every new job isnot only valuable from the social stand-point, but it also reduces expendituresfor unemployment benefits.

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1

Figure 1.11 The economic benefits of energy efficiency and renewables

Source: The authors

Energy efficiency and renewables

– Less dependenceon energy sources

– Less damage tothe climate andenvironment

– Greater tax revenue– Lower social costs

– Greater internationalcompetitiveness

– Lower societalcosts fromunemployment

– No wars overresources

– New jobs– Export markets

Environmentalbenefits

Social benefits and security

Economic benefits


2.1 Solar collectors

When sunlight hits a dark object, that objectheats up. This well known effect is behindsolar thermal systems. Solar collectorsconvert sunlight into usable heat. Theabsorber – a black plate made of copper,aluminium or sometimes even plastic insimple systems – is exposed to the sun,which heats the plate up. The heated platethen passes the heat on to a fluid (heatcarrier) flowing through tubes embedded inthe plate, and this fluid flows to theconsumer device (to provide heated servicewater). Various technologies are imple-mented to reduce heat losses:1

• Flat-plate collectors, the most commontype, have an absorber within a frame.The cover facing the sun is transparent,and the cover is well insulated to thesides and on the back. Such solar collec-tors are 50–60 per cent efficient at atemperature of 50˚ Celsius. They can,however, reach temperatures of up to80˚C under direct sunlight.

• Evacuated tube collectors have theirabsorbers inside a sort of thermos bottlethat is transparent on the side facing thesun. The vacuum reduces heat lossesgreatly. These evacuated collectors there-fore have greater efficiencies, especiallywhen the temperature difference is greatbetween the absorber and the ambientair. If the difference is 70K (= 70degrees), evacuated tube collectors arearound 15 per cent more efficient thanflat-plate collectors. But that figure dropsto only 5 per cent if the difference is40K. The benefits of evacuated tubecollectors thus make themselves feltespecially during the cold season. It

therefore makes sense to use them tosupport heating systems.

• When outdoor swimming pools areheated, heat loss is not that great anissue, so no insulation is generally used.The water is pumped through blackabsorber hoses to absorb the solar heat.Such systems are, however, only useful inapplications where only a few degrees ofheat is required, such as in outdoorpools.

Solar collectors also have to be properlyoriented to be efficient. In Germany, roofangles are optimally 45 degrees and facingdue south. Fortunately, efficiencies drop onlyslightly if these ideal values are missed;collectors still produce around 90 per cent oftheir rated output if the collectors have anangle between 0 degrees and 50 degreesand face anywhere from southeast to south-west. It is therefore possible to use a slightlylarger collector surface to compensate forsuboptimal orientation. Some evacuatedtube collectors even allow you to compen-sate by slightly turning the absorber withinthe tube.

2

2 Solar Thermal


41

Solar Thermal

2

Figure 2.1 Design of flat-plate collectors

Source: Schüle, Ufheil and Neumann: Thermische Solaranlagen, 1997

Glass cover

Hot wateroutput

AbsorberInsulation

Cold waterinput


2.2 Hot water from the sun

The heat from solar collectors is generallyused to provide heated service water, butthe hot water can also be used in heatingsystems. The solar thermal system is thencombined with the heating system; gener-ally, the solar heat suffices to cover allheating demand in the warm season andpart of heating demand in the cold season.

The technologySystems for single-family homes andduplexes are the most common today. Theygenerally have a dual circuit system (seeFigure 2.2). The solar circuit (solar collector,bottom heat exchanger and pump) containsa frost-proof fluid (a mixture of water andglycol) that transports heat to the heatingcircuit. Once the sun starts shining, thetemperature in the collector rises severaldegrees above the temperature in the lowerpart of the tank, setting off the pump in thesolar circuit by means of an electroniccontrol. The solar heat then passes from thelower heat exchanger into the service watertank, which should be large enough toprovide hot water for around two days.

Because hot water is lighter than cold water,the water heated with solar energy rises inthe tank. The water thus separates intolayers, with the lighter hot water at the topand the colder water at the bottom. Hotwater is then drawn from the top of thetank, where the stored water is always thehottest. If the sun ever fails to provideenough heat, the auxiliary heater canprovide extra heat via the top exchanger.

ExampleA solar thermal system with some 6m2 offlat-plate collectors and a 300 litre storagetank can generally cover hot water demandduring the warm season in a four-person

household. But even the solar heat duringthe cold season offsets the consumption ofaround 300 litres of heating oil per year inGermany. The net investment cost of around€5000.2

Decisive benefitSolar thermal systems that provide hotservice water not only replace the consump-tion of fossil fuels with solar energy, but alsovery effectively reduce pollution. Because oiland gas heaters run at low levels during thewarm season, they are especially inefficientthen and emit more pollution; the heatersgenerally only come on briefly and thereforedo not run in their optimal range. But if solarheat is used during the summer to heatservice water, you can leave your boiler offaltogether.

In addition to providing hot service water,larger solar thermal arrays can also provideheat for space heating during the spring andautumn. In such cases, the building shouldbe properly insulated and have a heatingsystem running at a low temperature. A12m2 solar thermal array can then reducefuel consumption by 20 per cent. Thiscombined use is becoming increasinglycommon on the market.3

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2

Figure 2.2 Solar hot water

Source: Schüle, Ufheil and Neumann: Thermische Solaranlagen, 1997

Hot water

Auxiliary heater

Cold water

Storage tank withenough capacity tostore solar hot waterfor a few days

Pipes to transportsolar heat to thestorage tank

Solar stationwith pump +controlsystem


2.3 Solar heating in districtheating networks

If you want to get a lot of your heatingenergy from solar heat, you have to taketwo factors into consideration:

1 Far more heat is required for spaceheating than to heat service water. In oldbuildings, 5–10 times as much energycan be required for space heating thanto provide hot tap water. But even inwell insulated homes, space heating canrequire two to three times more energy.For solar heat, the first goal is thereforeto reduce the building’s requirements forheating energy; in addition, far greatercollector areas are required when spaceheating is to be covered in addition tohot service water.

2 In the winter, when you need the mostspace heating, you have the least solarenergy. In January, the sun only providesa sixth of the energy it supplies in July atNorthern European latitudes.

The main problem with solar heating isgetting the excess heat from the summerstored for the winter. Long-term heatstorage tanks play a crucial role. Specificheat losses and specific costs both decreaseas the size of these storage tanks increases.Therefore, subterranean storage tanks aregenerally the best option.4 District heatingnetworks can then provide heat to adjacentbuildings from these underground tanks.

In other words, more solar heat can beprovided when buildings are well insulated,collector fields are large, a long-term storagetank is available and a district heatingnetwork can be connected to it.

In the 1980s, Sweden set up the first districtheating networks with solar heat. Germanyfollowed suit in 1996, with its first two solarpilot systems that included long-termstorage.

In a pilot project in Hamburg-Bramfeld, atotal of 3000m2 of collectors was installedon the roofs of 124 row houses in a newneighbourhood. The solar heat collectedwas stored centrally and distributed toconsumers via a district heating network.Any heat not used was fed to the long-termstorage tank, a 4500m3 concrete tank with astainless steel lining. The tank was insulatedon the outside to reduce heat loss. It filledup with heat in the summer, reaching itshighest temperature of around 80˚C inAugust. It then provided heat for spaceheating well into December. A condensationboiler was used to provide heat for the restof winter. The goal was to cover 50 per centof energy demand for heating and hotwater, and that goal was reached.

The cost of this solar heat (without subsidies)in the Hamburg project is 26 euro cents perkilowatt-hour, but another project inFriedrichshafen, which was larger and had alarger storage tank, provided heat at a priceof 16 euro cents per kilowatt-hour. By 2005,five other solar district heating networks hadbeen set up in Germany.5

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Solar Thermal

2

Figure 2.3 Solar thermal with long-term heat storage

Source: BINE, Solar Nahwärmekonzepte

Share of solar heat in overall heat consumption

Building with a 12 m2 solar array Building with connectionto district heating networkwith solar support

Central heating unit

Collector field of 5,600 m2

Naturalgas

Condensation boiler

Long-termstorage tank,12,000 m3 Collector

network

Hot waterstoragetank District

heatingnetwork


2.4 Cooling with the sun

At present, most air-conditioning and refrig-eration devices are vapour-compressionmachines. The refrigerants used, eventhough they do not contain CFCs, are notexactly environmentally friendly. And, ofcourse, these units consume a lot of power.Here, solar energy can also help offset theconsumption of fossil energy, reduce pollu-tion and reduce peak power demand. Itturns out that the most solar power is avail-able right when air-conditioning is neededmost. Buildings are not only mainly air-conditioned in the summer, but also duringthe day, which makes the costly long-termstorage required for solar heat unnecessaryhere.

There are various types of solar coolingbased on solar thermal heat.6 Those basedon low-temperature heat are especiallyuseful for solar applications. Below, wediscuss Desiccant Evaporative Cooling (DEC).

The technologyDEC is based on the principle that evaporat-ing water cools down its surroundings.7 Ahumidifier cools down the air by taking outthe heat as water evaporates from the previ-ously dried air.8 The dehumidifier containssilica gel that removes moisture from theincoming air by absorbing the moisture in itsown molecular structure. The silica gel there-fore has to be ‘regenerated’ (dried) forreuse, so when the outgoing air passes by, ittakes some of the moisture with it. The heatrequired in the process comes from solarcollectors, but it could also come from ashort-term storage tank with an auxiliaryheater.

ExampleIn 1996, a solar DEC system went into oper-ation as an air-conditioning system at astartup park in Saxony, Germany. Its 20m2 ofcollectors cover 75–80 per cent of the air-conditioning required.9

OutlookThere have already been a number ofsuccessful demonstration projects pertainingto solar air-conditioning. Serial production isgetting underway, but solar cooling stillcannot compete at current energy prices.Cost reductions are expected,10 and lessexpensive air collectors (see 2.5) areexpected to help bring down prices further.Such air collectors are especially usefultowards the equator. Properly planned build-ings in central Europe generally do not needair-conditioning, though special-purposerooms – such as for technology or assem-blies – are an exception. Here, it would makesense to have the collectors used all yearround. In the summer, they could provideair-conditioning; in the winter, spaceheating. In tropical countries, solar coolingcan help store food. Clearly, solar air-condi-tioning and cooling systems haveconsiderable potential.

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Solar Thermal

2

Figure 2.4 Cooling with the sun

Source: Sonnenenergie 1/99

Solar collector

Adsorption air-conditioning

Cool, dryincoming air

Hot, moistoutgoing air

Ventilator

Humidifier

Dehumidifier

Heatexchanger

Benefits:• No climate impact from refrigerants• Demand for cooling is greatest when the most solar energy is available• 70–80 per cent solar coverage possible


2.5 Solar drying – air collectors

Solar collectors containing fluids are fairlylow-tech, but air collectors allow solarenergy to be used for heating purposes in aneven simpler way. Here, a sheet that letsthrough light is pulled taut across a framejust 2.5cm or so above a black plate. Whensunlight hits this air collector, the airbetween the plate and the foil heats up. Ifthe collector is set up at an angle, the hot airrises, automatically creating air flow. If thecollector is completely horizontal, a ventila-tor is required, though it could run on solarpower.

Air collectors allow solar energy to be usedin drying applications. In many rural areas inthe tropics and subtropics, farmers only havethe wind and the sun to help them dry theirharvests to conserve produce. Often, theysimply spread fruits and vegetables outunder an open sky. Some of the harvest isgenerally lost to rodents and birds, whiledust, microorganisms, mildew, etc. reducequality. As a result, part of the harvest is lostor no longer marketable. Solar tunneldryers11 are an inexpensive way of conserv-ing such products without great losses orpoorer quality (see Figure 2.5). On an areasome 2m by 18m long and slightly raised offthe ground, a foil can be stretched acrosslike a pitched roof. Roughly half of the areaserves solely as an air collector, with theother half containing the products to bedried by the air heated up in the collector.Small ventilators powered by solar energycan be used to ensure that the air circulates.This process not only reduces harvest losses,but also cuts the time required for dryingroughly in half. Furthermore, the driedgoods are protected from precipitation,which is common in tropical countries; thedrying process continues without interrup-tion during rain. And if the rain continues

long enough to discontinue the supply ofsolar heat, a gas burner could provide auxil-iary heat. Such a tunnel dryer can provide upto 60kWh of solar energy per day, equivalentto the energy contained in some 15kg offirewood.

Air collectors can also be used in temperatezones.12 The energy yield is even higher thanwith flat-plate collectors for space heating.In energy-efficient buildings, air collectorsand ventilation systems can be combined ina number of interesting ways.13 For instance,at an indoor pool in Wiesbaden, Germany, a420m2 air collector heats the air inside,saving some 50,000m3 of natural gas eachyear.14 In Göttingen, Germany, a 343m2 aircollector on the wall of a heating plant pre-heats the combustion air with solar energy,reducing the amount of energy that theplant itself consumes.

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Solar Thermal

2

Figure 2.5 (1) Solar drying: How air collectors workFigure 2.5 (2) Solar drying: Solar tunnel dryer for agricultural products

Source: W. Mühlbauer and A. Esper, ‘Solare Trocknung’, in Sonnenenergie 6/1997

Hot air

Transparent foil

Air exit

Drying area

Expansion chamber

Gas burner

Solar module

Air entrance

Ventilator

Air collector

Cold air


2.6 Solar thermal power plants

Solar collectors can heat up to around 80˚C.But much higher temperatures can bereached when sunlight is concentrated. Thisconcentrated heat can then boil water andsteam can be used to drive a turbine togenerate electricity. In such cases, onespeaks of solar thermal power plants orconcentrated solar power (CSP).

In CSP plants, mirror systems track the sunand concentrate reflected light on a singlefocal point, where temperatures can reachup to 800˚C. There, a fluid is heated tocreate steam. The steam can then drive aconventional turbine like the ones used incoal and oil power plants. Unlike photo-voltaics (see Chapter 3), sunlight is notdirectly converted into electricity here, butrather indirectly via steam and a turbine.There are basically three types of CSP plants.

The most common type is parabolic troughplants. This technology has moved out ofthe pilot phase. In California’s MohaveDesert, nine such power plants have beenbuilt with a total mirror surface area of 2.3million square metres and a cumulativeoutput of 354MW. The mirrors curve arounda central tube at the focal point of the para-bolic trough. The fluid inside these tubes isheated up to 400˚C and used to generateelectricity. Such commercial systems havebeen under construction since 2002, whenSpain adopted special feed-in tariffs for solarthermal electricity. In mid-2006, construc-tion began on a 50MW parabolic troughplant, and dozens more were planned.15 Inother Mediterranean countries and the US,large concentrating solar power plants areunder construction or planned.16 In theDESERTEC project, giant parabolic powerplants are to be built in the Sahara to supply

electricity to the north African countries andto Europe.17

In dish Stirling systems, a large dish-shaped mirror focuses sunlight on a Stirlingengine, which uses the heat to generateelectricity. With mirror diameters rangingfrom 7–17m, power output ranges from10–50kW.

Solar tower plants concentrate sunlight ona single focal point like a dish Stirling systemdoes, but they do so with a large number ofmirrors that track the sun and concentrate iton the top of a tower, where steam isproduced. Pilot systems currently haveoutputs of 1–10MW.18

CSP plants can generate up to 200MW ofelectricity per plant. A study conducted bythe German Aerospace Centre found thatthe potential for Mediterranean countriesalone was up to 1500TWh, equivalent toroughly half of all power currently consumedin Europe.19

And when the heat-carrying medium isstored, electricity can also be produced fromsolar energy even in the evening when thesun is not shining.

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2

Figure 2.6 Solar thermal power plants

Source: The authors, Triolog

Parabolic trough power plant (concentration along an axis)

Solar rays

Absorber tube

Mirror

Solar tower power plant (concentration on a point)

Heliostats

ReceiverSolar rays


3.1 The heart of a PV array – thesolar cell

As described in Chapter 2, solar thermalenergy converts solar rays into heat.Photovoltaics is another way of using solarenergy. This technology is based on a wellknown effect in physics: some semiconduc-tors convert light directly into electricalcurrent. This chapter focuses on the mainapplications and the future of photovoltaicsas seen from today.

Just as the absorber is the heart – the partthat converts sunlight into heat – of a solarthermal array (see 2.1), the solar cell is theheart of a photovoltaic array. Spread outthinly over the largest possible area, thissemiconductor converts incident lightdirectly into electrical current.

The first solar cell was made using silicon in1954, and 90 per cent of all solar cellscurrently made worldwide are still manufac-tured using this basic semiconductormaterial.

How it worksIn a process called ‘doping’, impurities(generally boron and phosphor) are intro-duced to a wafer generally thinner than0.2mm consisting of highly pure silicon tocreate two layers with different electric prop-erties. When light reaches the solar cell, thecharge carriers (electrons) from one layerflow to the other layer, creating a voltage of0.5V at the contacts. This voltage within thesolar cell remains relatively constant, but thecurrent that comes out of the cell variesdepending on the size of the cell and theintensity of incident light.

To reach voltage levels commonly used (suchas 12V of direct current), multiple solar cellsare ‘switched in parallel’ (connected inrows). When the cells are laminated into asandwich between a glass pane on the topand a plastic foil on the back, you have afinished solar panel.

The efficiency of crystalline solar cellscommonly sold on the market is generallyaround 15 per cent under standard testconditions. As temperatures rise, the poweryield drops; ensuring that panels have someair underneath them to cool them off(natural ventilation) is therefore a good idea.

In addition to the silicon wafers describedhere, thin film has grown to cover roughly10 per cent of the market. Thin-film cellsgenerally consist of either amorphous siliconor some combination of copper, indium,gallium and selenium (CIS and CIGS), whichwill be discussed further in 3.5. Thin-filmcells are much thinner than traditional crys-talline silicon solar cells, and the productionmethods are also very different.

A number of other cell types are also beingdeveloped or in pilot production. The goal ofthis research and development is to makephotovoltaics, which is currently relativelyexpensive, cheaper by using less material orless expensive material.1

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3 Solar Electric: Photovoltaics


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3

Figure 3.1 The heart of a photovoltaic array: The silicon solar cell

Source: Leuchtner and Preiser, Photovoltaik-Marktübersicht, 1994

Negativeelectrode

Powerconsumer

Positiveelectrode

Positively dopedsilicon

Border layer

Negativelydoped silicon


3.2 Grid-connected PV arrays

Power generated from photovoltaics offers anumber of benefits:

• Emissions – PV arrays are silent and emitno waste gases.

• Service life – since there are no movingparts, solar arrays have very long servicelives. Manufacturers offer warranties of20 years and longer for solar panels.

• Environmental impact – silicon solar cellsare environmentally friendly during oper-ation and can be recycled without anyenvironmental impact.2

• Resources – silicon is the second mostcommon element on the Earth’s crust, soit is hard to imagine us running out ofthe raw material.

• Wide range of applications – photo-voltaics can be used in a large number ofapplications from pocket calculators andwristwatches to large solar power plants.

Thanks to these benefits and a number ofgovernmental policies to promote photo-voltaics, grid-connected arrays have becomea common sight on residential buildings inmany countries (see Figure 3.2). Generally,they have a rated output ranging from 1–10kilowatts-peak.3 Solar panels produce directcurrent, which an inverter converts intoalternating current so that the power can beexported to the grid. When solar power ismetered separately from consumption(double metering), compensation for solarpower can be decoupled from the retail rate(feed-in tariffs, see 11.10); this approachalso allows solar power generation to bemeasured for carbon trading and towardsrenewables targets, which net-metering(with a single meter) does not.

A PV array with a peak output of around2kW will take up some 20m2 of roof space.Depending on local conditions and thearray’s orientation, that array will generatesome 1700–2000kWh per year at Germanlatitudes, roughly as much power as a four-person household that conserves energywould consume. In 2010, such an arraywould cost less than €8000, with pricesfalling rapidly (see 3.5).

When feed-in rates were offered for photo-voltaics, businesses began to becomeinterested. They began to set up much largerarrays with lower specific costs on multi-family dwellings, roofs of commercialfacilities and farms. In 2006, arrays with arated output ranging from 10 kilowatts-peak to 1 megawatt-peak made up aroundhalf of the German market.4

Today, the largest PV power plants have apeak capacity of dozens of megawatts. A60MW array was completed in Olmedilla,Spain, in 2009 and there are plans to breakthe 100MW threshold in the US.

From Q4 2008 to Q3 2009, some 2.4GW ofphotovoltaics was installed in Germany,equivalent to the amount consumed by720,000 German households.

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Figure 3.2 Grid-connected photovoltaic arrays

Source: The authors

Solar cells

Inverter

Power meter

Grid connection


3.3 Off-grid PV arrays

Roughly 2 billion people worldwide – a thirdof the world’s population – have to make dowithout a power grid. Distributed electricitysupply to cover the basics would improvethe lives of these people considerably.Artificial lighting at night allows people onfarms and in shops to work later; schoolsand community centres can also offer moreflexible services. Radio, telephones and tele-vision provide information and means ofcommunication to remote regions. Thepower needed for such applications can beprovided less expensively and often fasterwith off-grid PV arrays than with grid expan-sion.5 Indeed, photovoltaics is often evenless expensive than small diesel generators.

The equipment used for such purposes isknown as Solar Home Systems (see Figure3.3), these consist of a solar panel roughly0.5m2 in size (around 50 watts-peak), abattery, a charge controller and threecompact fluorescent light bulbs (12/24V).Under five hours of full sunlight per day,such as systems can power a radio, the threelights, a black-and-white television andother small devices for several hours. Whilethat may not sound like much by Europeanstandards, it marks a crucial increase in thestandard of living for many people in devel-oping countries. Solar Home Systems for abasic power supply are available starting ataround US$500 – a lot of money for thetarget group. Suppliers have therefore comeup with suitable financing models.

For instance, Shell has the following strat-egy: ‘You cannot expect a shepherd in InnerMongolia to pay €500 or €1000 for a solararray. We have therefore come up with akind of lease. We finance the system andinstall it. Customers then pay for monthlyusage with a chip card that costs €7 for 30days. They then have to recharge it, forinstance at a Shell station or at their commu-nity centre. In this way, we get ourinvestment costs back.’

The benefits of these PV systems are soobvious that this market is growing quicklywithout any subsidies. In 2005, more than 2million households worldwide in developingcountries received new Solar Home Systems.In China alone, some 10,000 new systemswere installed per month in 2005.6

There are even situations in industrial coun-tries where off-grid PV systems are the bestoption. For instance, PV-powered parkingticket meters are cheaper than the ones thatrun solely on batteries or require a gridconnection. PV panels also make lightingpossible for remote bus stops (with motiondetectors to conserve electricity) to providegreater comfort and safety in public trans-port for rural areas. Farmers have also foundthat small PV arrays provide the cheapestpower sometimes, such as to power afishing pond aerator, an electrical fence andan irrigation pump.7

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Figure 3.3 Off-grid photovoltaic arrays

Source: The authors

Solar panel

Chargecontroller

Battery

Solar Home Systems enable an economical supply of electricity in off-grid regions


3.4 Solar energy as part ofsustainable development

Solar energy is by no means the only require-ment for sustainable development, butenergy supply does have to be extended ifstandards of living in rural areas of develop-ing countries are to be improved. Cubaprovides an interesting example of how solarenergy can raise standards of living for entirevillages.

Comprehensive rural electrification beganshortly after the Cuban revolution in 1959.From 1960 to 1992, the share of ruralhouseholds with electricity rose from 4 percent to 79 per cent. Because it would bevery expensive to expand the grid to coverthe remainder, some 500,000 remote homesstill did not have electricity in the 1990s. In1987, the Cuban government launched anambitious programme to provide electricityto even the most remote villages.

In the first phase, all health clinics in theseregions received solar power systems. Everyvillage has such a health clinic staffed by onedoctor and one nurse. This service is one ofthe reasons why Cuba’s health care system isa model for Latin America. The solar arraywith an output of 400W powers a refrigera-tor for medicine and a small television. It alsoensures that the clinic, which is often themain village meeting place, has sufficientlight. By the summer of 2002, 320 suchhealth clinics had received such solar powersystems.

In a second phase, schools in remote villagesreceived solar power systems. The Cubangovernment installed a 165W panel on 1900schools – enough power to light classroomsand power a colour television and VCR. Thecost per school was US$1480. Local peoplewere trained to service the solar array, thebattery and the devices. This solar electrifica-tion programme for schools was completedin 2002.8

In the third phase, which began in 2003, allhomes were to receive power within fiveyears. Most of them were to receive SolarHome Systems, with the panels producedlocally in Cuba. In areas where wind power,hydropower or biomass could be used inex-pensively, expansion into microgrids9 wasconsidered.

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Figure 3.4 A Cuban village school with solar power

Source: BMU, Sustainable Energy Policy Concepts (SePco). Photo: Dorothee Reinmüller

All schools in rural regions of Cuba use solar power


3.5 The outlook for PV – lowercosts from new technologiesand mass production

Silicon-based photovoltaics is a well devel-oped technology that reliably producesenvironmentally friendly solar power. Atpresent, however, solar power from grid-connected arrays still costs around 30–40eurocents in Germany per kilowatt-hour(depending on system size), roughly six toeight times as expensive as power from coalplants, though the price of solar power is afraction of that in prime locations in placeslike Arizona. Research and development inphotovoltaics has therefore mainly focusedon lowering costs, mainly by means of twoapproaches that go hand-in-hand: newtechnologies and mass production.

New technologies will provide greater effi-ciencies and make do with less material orless expensive material. Various approachesare currently being pursued:10

Thinner cellsOver the past ten years, cells have becomeincreasingly thinner – from 300 to 180microns of expensive, highly pure silicon. Butthin-film cells – mainly copper-indium-selenide (CIS) and cadmium telluride (CdTe) –make do with far thinner layers; CIS layers areonly five microns thick, which represents aconsiderable reduction in material consump-tion. And because these layers are applied toa substrate by means of vapour deposition,manufacturing costs are also lower. Expertsnonetheless believe that silicon cells willremain the main workhorse of photovoltaics.

Advanced designsThe surface structure can be optimized, forinstance, to capture more light by reflectingless of it back outside the cell. The resultwould be greater efficiency.

Concentrator systemsIf three types of semiconductor, each ofwhich absorbs a different part of the lightspectrum, are stacked on top of each other,efficiency increases dramatically. Such cellsare, however, much more expensive. But ifsimple optical mirrors and lenses are used toconcentrate light on such small cells, theenergy yield increases even as material costsdecrease.

Market development is also crucial in lower-ing costs. Industry will only be able to set upthe large production capacity required foreconomies of scale if markets are sufficientlylarge to absorb output. The last decadeclearly shows that greater solar panelproduction leads to lower panel prices (seeFigure 3.5). Germany’s 100,000 RoofsProgramme, which ran from 1999–2003,and the more recent Renewable Energy Act(see 11.9) set off this development inGermany by providing a safe investmentenvironment; the former with upfrontfunding, the latter with feed-in tariffs.Admittedly, the skyrocketing demand forsolar panels led to a bottleneck in the supplyof silicon in 2005, which temporarily keptmodule prices high.11 But the silicon shortfallhas been overcome, and prices for siliconsolar panels fell by around 25 per cent in2009 alone. Experts believe that grid parity –when solar power will cost the same aspower from the grid – is already beingreached in parts of southern Europe and thesouthwestern US, but even Germany isexpected to reach grid parity by around2013 because of its relatively high electricityprices.12 German PV success is the directresult of its feed-in rates for solar power.

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Figure 3.5 Prospects for photovoltaics: Lower costs from new technologies and massproduction

Source: BMU, Erneuerbare Energien, 2006

4,000

3,500

3,000

2,500

2,000

1,500

1,000

500

0

2.00

1.75

1.50

1.25

1.00

0.75

0.50

0.25

0.00

Installed capacity in MWp Power costs in euros/kWh

Power costs Installed capacity


4.1 A third of the pie – spaceheating

The construction sector plays a special role inour solar strategy because roughly a third ofthe final energy consumed in industrialcountries such as Germany is used to heatbuildings. Indeed, more energy is used toheat apartments, offices, public buildings,etc. than in the entire transport sector. Yet,there are many ways to use solar energy forthese purposes (low-temperature heat). Wewill discuss these solar options in thischapter.

The average German building requires some220kWh of heat per square metre per year,equivalent to 22 litres of heating oil or 22m3

of natural gas. Most of this energy wouldnot be required if buildings were properlyinsulated. In the past few years, legislatorshave fortunately begun setting up require-ments for insulation. For instance, Germanyrequired all new buildings to make do with100kWh per square metre a year in 1995.1

‘Low-energy buildings’ make do with muchless. Here, ventilation systems are added toimproved insulation so that homes (inGermany) only need around 50–70kWh persquare metre a year for heating – roughly5–7 litres of oil, only a quarter of the averagefor buildings constructed before 1995. InSweden, the low-energy standard was mademandatory for all new buildings at thebeginning of the 1990s. Germany did notimplement this standard until 2002.2

In its revised Energy Performance ofBuildings Directive, the EU requires all newbuildings to be ‘nearly zero-energy’ by 2020.Though that may sound like an ambitioustarget, zero-energy buildings have beenaround since at least the 1990s. The off-gridsolar home (4.7) was opened in 1992 as apilot project, but zero-energy homes,numerous passive houses (4.6) and plus-energy homes (4.8) constructed over thepast two decades show that homes can dowithout conventional heating systemswithout any loss of comfort even at Germanlatitudes. Such homes are becoming increas-ingly attractive for buyers; they will have tobecome the standard for the transition tothe Solar Age.

But standards for new buildings will not takeus far. The greatest energy conservationpotential comes from renovations of oldbuildings. A solar strategy that focuses solelyon new buildings will therefore fall short ofthe mark. Rather, the insights gained fromprogressive building standards must be usedfor renovation projects as well. Solar thermalsystems and transparent insulation will playan important role here (4.4 and 4.5).

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Figure 4.1 Space heating: A comparison of key energy figures in various building standards

Source: The authors

Energy consumption in kWh/m2/a

Electricity

Hot water

Space heating

Oldbuildings

WSchVo95

EnEV2002

Passivehouses

Plus-energyhomes


4.2 Passive solar energy

‘Passive’ solar energy means that solarenergy is used to help heat a building in thewinter without any complicated technology,such as pumps, heating circuits, etc. Thereare basically two ways to use solar energypassively:3

1 Special components, such as windows,glass façades and transparent insulation.

The type and design of the windows usedare especially important because everyhouse has them. The technology in this fieldhas made significant progress over the pastfew decades. At the end of the 1970s, insu-lated double glazing was considered a goodstandard. By adding a coating that reflectsheat and by filling the space between thepanes with a noble gas, modern insulatingwindows can reduce heat loss by around 60per cent (Ug = 1.2 instead of 2.8 for ‘normal’insulating glazing4); triple glazing (Ug = 0.7)even increases that reduction to 75 per cent.

But if we are to use solar energy, we not onlyneed to make sure that as little heat as possi-ble passes out of the building in the winterthrough the windows; we also want asmuch solar energy as possible to enter thehouse through the windows. As the insula-tion of windows becomes better, the solarinput is also reduced even as heat losses outof the building drop considerably.Nonetheless, south-facing, insulatedwindows have a positive energy payback.These windows allow more heat to enter thehouse than they allow to exit over the year.

Solar architecture takes advantage of thiseffect by reducing the building’s energydemand with a greater share of south-facingglazing (in the northern hemisphere). North-facing windows cannot provide such heat

input owing to a lack of direct sunlight.Therefore, windows on the north side of thebuilding are kept as small as possible if abuilding is to be heated.

Likewise, in the southern hemisphere,windows on the north side would be madelarger to allow more heat to come into thebuilding. And wherever a building is to bekept cool, the windows on the side with themost sunlight would be made smaller.

2 Solar architecture, such as selecting theproper location and orientation for abuilding, adapting the shape of thebuilding, using the roof to provideshading, and planting trees to provideshading.

The use of the roof to provide shading forsouth-facing windows is especially interest-ing (see Figure 4.2). In many buildings,sunlight in the summer creates excessiveheat indoors, requiring energy-intensive airconditioning. To prevent this, solar energyinput has to be reduced passively, i.e.without much technology. By having theroof eaves extend out over the façade, theroof itself provides a simple, but effectiveshading mechanism when the sun is high upin the sky during the summer. At the sametime, the eaves should not extend out so faras to prevent direct sunlight from enteringthe building in the winter.

This example shows how traditional types ofarchitecture use the sun. In the age of cheapoil, we have simply lost sight of a lot of theseoptions. For the transition to the Solar Age,we need to fall back on this knowledge andcombine it with new materials and tech-nologies.5

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Figure 4.2 Passive solar energy: South-facing windows and roof overhangs instead ofheaters and air conditioners

Source: The authors

Summer(Sun is highin the sky)

Winter(Sun is lowin the sky)

Winter: south-facing windows allow sun to enter the buildingSummer: roof overhang keeps indoor area from overheating


4.3 The solar optimization ofurban planning

Urban planning experts decide what kind ofbuilding (single-family homes, row houses,apartment complexes, etc.) can be builtwhere, how far apart they have to be andhow they can be oriented towards thestreet. Until recently, energy considerationshardly played a role in such decisions. Buttoday, it is possible to simulate future energyconsumption and the potential of thepassive use of solar energy during the plan-ning process so that development plans canbe optimized to reduce energy consumptionand increase the use of solar energy.

Three aspects are especially important here:

CompactnessCompact buildings use less energy becausethey have a greater volume for a givensurface area, where heat losses occur. Forinstance, five single-family homes consume20 per cent more energy than five rowhouses with the same floor space. In turn,five apartments of the same size in acompact complex would lower heatingenergy consumption by as much as a further20 per cent.

OrientationThe orientation of buildings determines theextent to which solar energy can be usedpassively. For instance, heating energydemand increases by as much as 15 per centif a low-energy house is poorly oriented.And an optimal southern façade is evenmore important for passive houses (see 4.6).

ShadingMost heating energy is needed in the coldseason, when the sun is the lowest in the sky– and the buildings tend to shade each otherthe most, thereby preventing the passive use

of solar energy. Over the year, shading canincrease demand for heating energy by 10per cent in low-energy housing. For passivehouses, shading should be avoided alto-gether.

The ways and extent to which solar energycan be used largely depend upon develop-ment plans. Specifications for rooforientation are especially important.Furthermore, specifications about individualor district heating systems are often alreadyspecified in urban development plans, sothat ecological district heating networks(cogeneration, woodchip heaters, etc.) haveto be taken into consideration during urbanplanning. Urban planning cannot, however,specify everything – for example, inGermany urban planners may not legally beable to require better insulation, thoughsuch requirements can be a part of privatecontracts.6

Optimizing urban development plans toconserve energy and step up the use of solarenergy generally reduces demand forheating energy by 5–15 per cent, thoughthat figure may rise to 40 per cent in somecases. In the light of such savings, the extracosts for more careful planning seem negli-gible.7 A community that neglects to takeenergy conservation and solar energy intoaccount in its urban planning therefore notonly wastes money, but also makes the tran-sition to the Solar Age harder.

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Figure 4.3 Solar optimization of urban planning

Source: Deutsches Ingenierblatt, Sept 1996

Comparison of two competitive designs

Draft A

Draft B

Shading 23.0 per cent

Specific heating energy demand in kWh/m2/year 22.4

Shading 11.1 per cent

Specific heating energy demand in kWh/m2/year 20.8

i.e. 7 per cent lower

The relative lack of shading in draft B reduces energy consumption.


4.4 Solar thermal and PV inrenovation

Buildings from the 1960s and earlier requiremuch more heating energy than morerecent buildings. Modernizing these build-ings to fulfil current building standards istherefore crucial in our solar strategybecause the greatest savings potential ishere – in Germany, roughly 20 per cent ofoverall current energy consumption could beoffset through renovation.

Of course, every building has to be investi-gated individually to determine which stepswould conserve the most energy inexpen-sively. But regardless of the details of aspecific building, experience provides somegeneral guidelines for such renovation proj-ects. For instance, the greatest savings in therenovation of residential buildingsconstructed before 1980 usually comes fromthe addition of insulation to external walls.The installation of new windows and doorswith a special insulating glass and betterroof insulation also provides considerableenergy savings. While insulating the bottomfloor and the uppermost ceiling does notprovide tremendous energy savings, thesemeasures are, however, often very prof-itable. New heaters generally also run muchmore efficiently than old ones, therebyreducing primary energy demand. Overall,all of these measures taken together ofteneasily allow energy consumption to bereduced by 50–70 per cent or more in atypical residential building.

Additional conservation measures thenoften become very expensive, but the use ofsolar energy can then be a good option. Asolar thermal array can help reduce energyconsumption even further.

ExampleIn the renovation and expansion of an endterrace house from the 1920s,8 energyconservation measures reduced energydemand from some 320kWh per squaremetre a year to around 80kWh, roughly aquarter of the original value even as thefloor space was greatly increased. The instal-lation of a large solar thermal array (23m2)further cut heating demand in half toaround 40kWh (see Figure 4.4). While thesavings from the solar array only amount toaround 12 per cent in terms of the originalvalue for heating demand, comprehensiverenovation increases the share of savingsfrom solar energy.

Such renovations require upfront financing,and the German KfW Bank, a state organi-zation, provides low-interest loans for suchprojects. If the renovation project brings thebuilding to the current standard for newbuildings, the bank underwrites up to 15 percent of the loan.9 Any solar thermal systemsused are included in the savings, so if reno-vation alone does not bring a project farenough to qualify for the write-down, theenergy offset by solar energy is counted.10

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Figure 4.4 Solar arrays as a component of renovation: Reducing energy consumption withand without solar arrays

Source: Ranft and Haas-Arndt, Energieeffiziente Altbauten, 2004

Energy consumption in kWh/m2/a

Electricity

Hot water

Space heating

Beforerenovation

Afterrenovation

After renovationwith solar

thermal and PV(solar energy

deducted)

Solar energy can be used to provide considerable savings in electricity andheat consumption in renovation projects


4.5 The wall as a heater –transparent insulation

How it worksConventional insulation prevents the trans-fer of heat between the outside and theinside. But when sunlight hits a façade, itheats up the building’s membrane. Insteadof preventing this heat from entering thebuilding, transparent insulation channels theheat to an absorber layer on the inside ofthe wall. The heat is then passed on withsome delay (generally several hours) to theinside of the building, essentially making thewall a large radiator. The warm walls alsocreate a more pleasant atmosphere insidethe building.11

Generally, aerogel or transparent plastic isused in such transparent insulation. Capillaryor honeycomb structures help enable thecombination of transparency and insulation.Most such products require a pane of glassfor weather protection.

Energy yieldA square metre of transparent insulation canoffset the consumption of 5–40 litres of oilper year, with 15 litres being a roughaverage. On energy-efficient new buildings,a south-facing façade with such transparentinsulation can reduce the demand forheating energy by around 20 per cent.Renovated buildings also benefit from theadditional insulation. A renovation project atthe Paul Robeson School, a prefabricatedconcrete structure in the German town ofLeipzig, provided some interesting results.Here, 300m2 of transparent insulation wasinstalled, and although the sun is not veryintense in the winter, heat was still providedin those months.

Walls with conventional insulation stillrequired 43kWh of heating energy persquare metre over the year even after reno-vation. The walls with transparent insulation,however, reduced these losses completelyand even produced a slight heat gain overthe year of 2.3kWh per square metre.12

A rule of thumbAutomatic shading systems or architecturalshading elements (such as balconies) arerequired to prevent overheating in thesummer. Because mechanical systems (lines)malfunction easily, simpler systems arerecommended. For instance, if a pane ofglass with a prism structure that reflectssummer sunlight in particular is used overthe transparent insulation instead of anormal pane of glass, it will provide roughlythe same shading as a roof overhanging by1m.13

Because transparent insulation systems arestill not mass-produced, the costs are muchhigher than for conventional insulation, butsandwich insulation systems (exterior insula-tion finishing systems or EIFS), whichcombine the transparent insulation platewith light-permeable plaster, are relativelyinexpensive.14

Transparent insulation has been under devel-opment since the beginning of the 1980s,and hundreds of buildings have suchfaçades in Germany covering some50,000m2 of wall area. Transparent insula-tion will play a major role in the renovationof buildings in the future.15 One importantnew application is the use of transparentinsulation to detract light in daylightingelements used in gymnasiums, museums,industrial halls, etc.

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Figure 4.5 Walls as heaters: Transparent insulation

Source: BINE: Transparente Wärmedämmung zur Gebäudeheizung, Bonn 1996

Classic (opaque) insulation

Classic insulation

Solar rays

Heatinput

Transparent insulation


Solar rays

Heatinput


4.6 Homes without heaters –passive houses

Passive houses are the further developmentof low-energy houses with the followingadditional elements:

• Excellent external insulation, includingtriple glazing.

• Optimized passive use of solar energywith large south-facing windows.

• Regulated ventilation with heat recovery.

At German latitudes, passive houses can dowithout conventional heating systems. Theirheating energy demand does not exceed15kWhm2 over the year, roughly a quarter ofwhat a low-energy house requires(50–70kWh, see 4.1).

To ensure that such homes do not get toohot or too cold, the building’s heat input andoutput have to be carefully coordinated.Heat can be output from the buildingthrough the ventilation system and transmis-sion (heat losses through walls, windows,ceilings, etc.), whereas heat input to thebuilding can be reduced with insulation.

There are four types of heat:

1 Internal sources, in other words the heatthat people, animals and applianceswithin the house generate. As Germanarchitect Meinhard Hansen likes to say,the average adult gives off as much heatas a 100W lightbulb.

2 The passive use of solar energy, for instance,the solar heat input through windows.

3 Heat recovered by a heat exchanger inthe ventilation system.

4 An auxiliary heater when the other heatsources do not suffice.

In old buildings, especially those from the1960s, heat losses from the building’s

membrane are so great that heat from withinthe building and passive solar input are negli-gible. Almost all of the heat input has tocome from a heater. In contrast, the passivesolar input is optimized in passive houses, andthe building’s compactness and excellentinsulation reduces heat losses drastically.Furthermore, the ventilation system recoversheat to compensate for losses in ventilation.The remaining 15kWh of heating energy persquare metre that is still required each year isequivalent to the amount of heat given off bya 100W light bulb running all the time.16 Inpractice, this slight amount of residual heatcan come from a small heat pump integratedin the ventilation system.

The first passive house was constructed in1999 in Darmstadt, Germany. By the end of2009, around 17,500 passive houses had beencompleted in Europe, some 13,000 of whichare in Germany. Several of them are entireneighbourhoods. Scientific follow-up studieshave confirmed the low energy consumptionand excellent comfort standards.17

Some passive houses already cost the sameas conventional homes, which is really notsurprising when we remember that passivehouses do not require much high-tech.18

Conventional buildings also have a roof,walls and windows, so only the buildingcomponents have to be of much betterquality. The additional upfront costs offsetconsiderable upfront costs for heatingsystems since the building can not only dowithout a large heater, but also fireplaces.

The share of energy-efficient homes willquickly grow in light of all of these benefits.19

Different types of passive houses are goingup all over Europe – as stand-alone single-family homes, row houses or apartmentcomplexes. Indeed, nurseries, schools,gymnasiums and office buildings have alsobeen constructed as passive houses.20

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Figure 4.6 Homes without heaters: Passive houses

Source: Phasea, Fraunhöfer Institute for Solar Energy Systems, Ralf Killian

Large, very wellinsulated south-facing glazing– greater solar

gains

Excellent generalinsulation– lower heat losses

(transmission)

Controlled ventilationwith heat recovery– provides fresh air

and recovers heatfrom outgoing air

As a result, almost no heating energy is needed


4.7 The off-grid solar house – a model for the Solar Age?

In 1992, the Fraunhöfer Institute for SolarEnergy Systems opened its Energy-Autonomous Solar House in Freiburg,Germany, as a research and demonstrationproject.21 With 145m2 of floor space on twostories, it has five rooms, a kitchen and ancil-lary rooms. This house proved that asingle-family home could make do with thesolar energy from its roof and walls thewhole year even in the German climate. The‘autonomy’ here thus concerns not onlyspace heating, but also hot water, gas forcooking, and electricity. Several years ofoperation demonstrated that this independ-ence is possible without any loss of comfortfor residents.22 Like a passive house, thishouse has:

• Extremely good insulation.• Large southern windows to exploit solar

energy passively.• Regulated ventilation with heat recovery.

The following technologies were also used:

• Highly efficient solar thermal collectors(14m2 with a 1000 litre storage tank)provide enough hot water almost all yearround.

• Large areas of transparent insulation(some 70m2) reduce heating demanddown to 0.5kWhm2 over a year – onlyaround 1 per cent of the energy neededin a low-energy house and around 4 percent of what a passive house needs.

• A photovoltaic array (4.2 kilowatts-peak)generates some 3200kWh of electricityper year, more than the efficient appli-ances used in the household (60 per centless energy consumption than withconventional appliances) need. Excesselectricity is used to convert water into

oxygen and hydrogen, with the latterbeing stored in tanks. The hydrogen isused for cooking and auxiliary heat a fewdays a year. When the photovoltaicpanels have not been receiving enoughsunlight, the hydrogen can also be usedto power a fuel cell, which generateselectricity. The waste heat created in theprocess is used to heat service water.

Is the off-grid solar house a modelfor the Solar Age?The Energy-Autonomous Solar House doesnot have a grid connection, nor is itconnected to a district heating network. Assuch, crucial solar options – district heatingwith solar energy or biomass and the use ofother renewable energy sources, forinstance, are not possible here. As a result,this project required a large amount ofseasonal storage that would not have beennecessary if the house had been connectedto public heat and power sources. The SolarHouse therefore did not show what houseswould look like in the Solar Age, rather, itshowed that a house in Germany can dowithout fossil fuel even in the 1990s

Finally, the Energy-Autonomous Solar Housealso showed that solar architecture is not asingle technology, but rather a cornucopia oftechnologies that have to be closely coordi-nated to produce optimal results.

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Figure 4.7 The Energy-Autonomous Solar House, Freiburg, Germany

Source: Fraunhöfer Institute for Solar Energy Systems

Photovoltaic array(4.2kW)

Solar collectors (14m2)

Controlled ventilation

Extremely goodinsulation

Large, south-facingglazing for passive

solar energy


(roughly 70m2)


4.8 Plus-energy houses

Generally, homes are energy consumers, notproducers. They need heating energy andelectricity, which they get from outside. Buta model project in Freiburg, Germany, turnsthe table. The houses in the Solar Estateneighbourhood not only cover their ownenergy demand, but also export excess elec-tricity to the grid.23

The technologies in this residential area havealready been presented in the previoussections. They were simply recombined here.

• As in passive houses, excellent externalinsulation on the walls, windows androofs is combined with a ventilationsystem with heat recovery and largesouth-facing windows that passively usesolar energy to cover the remainingresidual energy demand, which rangesfrom 6–12kWh per square metre a yearin this project – considerably below thepassive house standard (15kWh).

• Solar thermal collectors provide up to 60per cent of the heat needed for hotwater; to keep the roofs clear for photo-voltaics, tube collectors are installed onbalcony railings.24

• The small amount of energy still neededfor heating and hot water can beprovided in a number of ways. Forinstance, the Solar Estate in Freiburg isconnected to a district heating networkthat gets its heat from a cogenerationunit. A similar project in the southernGerman town of Ulm was to use a stovefired with wood pellets in an automaticfeed system (for more on wood pelletstoves, see 5.4), though the projectnever came to fruition.

• The large roofs facing the south havephotovoltaic arrays with outputs rangingfrom 4–7 kilowatts-peak (depending onthe size of the roof). Over the course ofthe year, they generally produce far moreelectricity than residents consume,allowing large amounts of excess solarpower to be fed to the grid.

Overall, these homes export more energy(solar electricity) than they import (forheating). They are therefore called plus-energy homes.

Figure 4.8 provides an overview of thevarious components used in these homes. Italso makes another crucial aspect clear: theasymmetrical cross-section of the house isno accident, but rather a useful way ofimproving the use of solar power. Here, theroof peak is not in the middle, but rathertowards the northern side of the building,making the south-facing part of the rooflarger so that the photovoltaic array can alsobe bigger. If the roof peak were moved allthe way back to the north, the space thatcould be used for solar panels wouldincrease, but there would also be two draw-backs: the height of the roof would be muchgreater if the ideal angle for the solar panelswere retained, and that greater height couldconflict with building codes; and the housewould also shade its neighbour to the north,reducing the potential for the passive use ofsolar energy in the back. The cross-sectionchosen in these homes is therefore a goodcompromise between a large PV area andlow shading of the neighbours.

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Figure 4.8 Plus-energy homes

Source: Based on Disch. Photo: Michael Eckmann

Plus-energy house:– The photovoltaic array on the roof

generates more energy than theinhabitants need for spaceheating, hot water and electricalappliances.

Photovoltaics:solar input

Solar collector:solar input

Passive solarinput

Wood pelletstove

Gridconnection

Radiator

Distributed ventilationwith heat recovery

Hot waterstorage


5.1 Fields and forests as solarcollectors

Solar energy has always been used on alarge scale in agriculture and forestry. Plantsabsorb the energy in sunlight and storesome of it chemically – as biomass. Whenanimals eat these plants, another type ofbiomass is created as a byproduct: manure.Overall, biomass can be divided into threecategories in terms of energy use:

1 Wet biomass (manure in particular, butalso freshly cut plants) can be used tocreate biogas when allowed to fermentin an oxygen-free environment. Thebiogas can then be used to generateelectricity, heat or both. Waste gas fromtrash and water purification can also beused in this way, and organic waste canalso be fermented (see 5.2 and 5.3).

2 Dry biomass (wood and straw) can beburned to generate electricity and heat.In addition to straw (a waste productfrom agriculture), waste wood fromforestry and timber byproducts fromindustry (sawdust, wood chips, etc.) canalso be used (see 5.4 and 5.5).

3 Dedicated energy crops (rapeseed, corn,poplars, miscanthus, etc.) can also beplanted to provide additional biomass,which can be used in a number of waysto make electricity, heat and fuels (see5.6–5.9).

Wet and dry biomass are generally a byprod-uct or waste product of current industrialprocesses; therefore they generally need tobe disposed of as waste. Using them as asource of energy would allow this materialto be recycled, thereby reducing waste.Waste wood, straw and biogas from agricul-

ture could cover some 5 per cent ofGermany’s primary energy demand.1 Specialenergy crops would increase that share evenfurther.2

Biomass can be used in many ways – tomake electricity, heat and fuels. But while itspotential is great, the principles of ecologicalagriculture must be upheld.

Furthermore, a number of principal limitsmust be kept in mind. Conventional agricul-ture itself must be made more ecological.The reasons for a change in agricultureinclude, but are not limited to, nitrate ingroundwater, hormones in meat, the disap-pearance of entire species and soil pollution.Extensive agriculture, which requires a muchlarger area for the same production, is animportant step in the right direction,3 butthis requirement limits the amount of landavailable for energy crops.

In addition, plantations and harvests ofenergy crops require energy for tractors andthe irrigation. They first consume energybefore producing it. This energy input has tobe taken into consideration when calculat-ing the energy payback of energy crops.

A number of energy crop concepts only payfor themselves because they are highly subsi-dized. If agrarian policy was restructuredwith a focus on ecology, the number ofenergy crops available would be reduced.

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Figure 5.1 Forests and fields as solar collectors: The many ways of using biomass

Source: The authors

Dry biomass Energy crops Wet biomass

Wood, strawPoplars, grain, rapeseed,

corn, etc.Manure, fresh cuttings

Combustion/gasification

FermentationPressing andesterification

Fermentation

biogasalcohol

Heat + power Fuel Heat + power


5.2 Biogas

In Germany, biogas units are mainly used onfarms. Excrement from farm animals and, toan increasing extent, dedicated energycrops, are first ground up into a homoge-nous substrate. In a second step, thismixture is pumped into a heated, insulatedfermenter, where anaerobic bacteria breakdown the organic substance to createbiogas. The fermented substrate is thenpumped into a storage tank.

Biogas consists of around 65 per centmethane and 30 per cent carbon dioxide(CO2). Its energy content is around6–6.5kWhm3, compared to 9.8kWh fornatural gas. The energy content of biogasgreatly depends upon the substrate’scomposition and the time it spends in afermenter. For instance, a ton of cattle dungwill produce some 45m3 of biogas, while aton of corn will produce around 180m3.Most of this biogas is currently used togenerate electricity in Germany (see 5.3).Roughly a third of the waste heat created inthe process is used to heat up the fermenterto the optimal temperature for the bacteria.A farm with 120 cows can produce around100m3 of biogas a day, equivalent to theamount of heat in 23,000 litres of oil peryear.4 The profitability of biogas unitsdepends on a number of factors, thougheconomic feasibility increases along with theunit’s size.

Biogas units are not only used because ofthe energy benefits; they also provide specialbenefits for agriculture. For instance,fermentation improves the value of themanure used as fertilizer by making it morepalatable to plants. In addition, the substrateis more homogenous and can therefore bepumped more easily. Finally, manure doesnot have such a strong smell after fermenta-tion when sprayed onto fields.

Organic waste and wastewater fromkitchens are also becoming increasinglyimportant. In particular, the focus is onwaste containing fats and oil, such as oilused for deep-frying. When used to createbiogas, these oils not only no longer have tobe disposed of, but they also increase biogasproduction considerably. Organic waste,such as fresh cuttings and kitchen waste,cannot, however, simply be combusted likestraw and wood because of the higherwater content. But when they are mixed intoa biogas slurry, they can be used withoutfurther ado.

At the end of 2008, there were some 4000biogas units in Germany,5 and roughly twiceas many in Europe. Indeed, biogas units caneven be used in cities. For instance, a newresidential area in the northern Germantown of Lübeck widely uses the kind ofvacuum toilets commonly seen in high-speed trains and airplanes. This approachnot only saves water, but also allows wasteto be fed directly into a biogas unit withouthaving to go through a sewage system first(www.flintenbreite.de).

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Figure 5.2 Diagram of a biogas unit

Source: Energie für helle Köpfe

StallWaste fromkitchens andbutchers, freshcuttings

Condensationseparator Filter

Biogas HeatingHot waterGas engine

Gas heater

WaterInternal gasconsumption(around 20 per cent)

Low-odour fertilizer

Collector

Liquidmanure

Churningunit

Insulated fermenter Manure storage

Benefits:• Biological waste is used as a source of energy• Agricultural waste can be better used as fertilizer• Odours are reduced• New revenue stream for farmers


5.3 Biogas cogeneration units

Under German law, electricity from biogasunits receives special compensation (feed-intariff). If a biogas unit is then run as a cogen-eration unit, the generator’s waste heat canthen not only be used to heat the fermenter,but also to provide space heat. The powergenerated can be used internally or exportedto the grid. In the latter case, around 10eurocents per kilowatt-hour is paid undercurrent German law (see 11.10). If dedicatedenergy crops are mixed in with liquid andsolid manure to create biogas, a 6 per centbiomass bonus is also paid. The financialincentive is so attractive that almost allbiogas units in Germany are used mainly togenerate electricity.

Germany’s Renewable Energy Act, whichtook effect in 2000, gave biogas units astrong push. From 2000–2009, the numberof biogas units rose fivefold to around 4800,and the average output of new systems rosefrom 75kW to 350kW from 2000–2003.6

The biomass bonus stepped things up evenfurther.7 The main energy plant used is corn.For each kilowatt of installed capacity,roughly 0.5ha (around 1.25 acres) of cornneeds to be planted8 (see 5.6 and 5.10).

Cogeneration units that use biogas are alsoremarkable for two reasons. First, theircarbon balance is excellent. Biogas is itselfcarbon-neutral because only the amount ofcarbon that the plants took out of theatmosphere is emitted when the substrate isfermented and the gas combusted.Furthermore, when this gas is used to powera cogeneration unit, electricity from anothersource (such as a coal plant) is offset, leadingto carbon reductions there. Finally, whereasmethane, a heat-trapping gas, enters theatmosphere when biomass is allowed todecompose, it does not when used to

generate electricity. In the process, thebiogas cogeneration unit’s climate impactimproves further. Overall, emissions frombiowaste are reduced by some 100kg ofgreenhouse gases when used in a cogenera-tion unit rather than used to makecompost.9 A biogas cogeneration unit istherefore not only carbon-neutral duringoperation, but also actually reduces green-house gas emissions in the larger picture,making these units carbon and methanesinks.

The second thing that makes cogenerationunits remarkable is the special role they playin a solar energy supply. As is well known,electricity is hard to store. Concepts for asolar power supply therefore have aproblem: solar and wind power naturallyfluctuate, requiring additional power gener-ation capacity on cloudy days with littlewind. This is where biogas cogenerationunits come in. After all, biogas is easy tostore, so that such units can be ramped upand down as the grid demands. In otherwords, biogas can compensate for some ofthe fluctuations in solar and wind power.

Over the long term, additional storage andcontrol techniques will be needed to adjustthe supply of solar energy to demand.Biogas cogeneration units will play a rolehere (see 10.1).

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Figure 5.3 Biogas cogeneration unit lowers CO2 by offsetting other CO2-intensivegeneration sources

Source: Authors’ representation based on GEMIS, Öko-Institut e.V.

CO2 emissions in g/kWh of electricity

1,200

1,000

800

600

400

200

0

–200

–400

Coal plant

Coal plant for heating

Nuclear plant

Gas-fired cogeneration unit

Photovoltaics

Wind turbine

Biogas cogeneration

unit


5.4 Wood as a source of energy

A lot of progress has been made in usingwood as a source of energy over the pastfew years, both in terms of quality (betterequipment considerably reduced toxic emis-sions) and quantity (fast growth on themarket for wood-fired heating systems).Austria, Sweden and Switzerland are theleading countries in this field. These days,wood-fired heating systems are not onlyoffered for individual apartments, but forentire neighbourhoods, with systemsranging from several kilowatts to severalthousand kilowatts. Furthermore, cogenera-tion units fired with wood gas being furtherdeveloped and run as pilot systems.

Stoves and boilers fired with wood pelletsand a district heating systems fired withwood chips have the best chance of marketsuccess for the use of wood as a source ofenergy (see 5.5).

Wood pellets are essentially compressedsawdust. The pellets can be automaticallyfed into the burner, which means that fire-wood does not have to be added by hand.Rising oil prices and other events have madewood pellets stoves quite popular in recentyears. Pellets are currently produced in some30 locations in Germany, and the number ofsystems has risen to around 125,000 in theyear 2010.10 Pilot projects have demon-strated that wood pellets can also be used togenerate electricity and heat in cogenerationunits.11

Wood energy offers a number of crucialbenefits:

• Wood is a carbon-neutral fuel. If theamount of wood we take out of theforest never exceeds the amount thatcan grow back (in line with the principle

of sustainability), then wood fuel wouldnever emit more carbon than the trees inthe forest absorb.

• If sustainably managed, forests wouldnot be exhausted. Wood is therefore ahighly reliable source of energy.

• The use of wood as an energy sourcestrengthens regional added value,thereby securing local jobs. Wood isregionally available almost everywhere.Transportation is therefore short, andless local money has to be spent on oiland gas imports, thereby increasingadded value within the region. A Swissstudy demonstrated that six times asmuch money stays within the regionwhen wood replaces oil as a source ofenergy. At the same time, eight times asmany local jobs are created.12

• The forestry sector would get anotherglobal market for its products. The addi-tional revenue could then be used toimprove forest management, forinstance.

Wood heaters can easily be used in conjunc-tion with solar thermal energy. Becausewood boilers cannot be ramped up anddown very easily, they are not that usefulduring the warm season, when heatingdemand is low. During these months, a fossilfuel is generally used instead of woodbecause such boilers are easier to adjust. Buta solar thermal array can complement awood heater very well. The former providesheat during the summer; the latter, duringthe winter. Over the year, you then get all ofyour heat from renewables.

In Austria, and increasingly in Germany, suchsystems are becoming popular. Woodheaters in combination with solar arrays canalso be used in connection with districtheating networks.13

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Figure 5.4 Getting energy from wood

Source: The authors

Wood regenerates No risk in energyimports (such as oil

spills)

Helps protectclimate

Local jobs

Regional added value

New sales market for the timber sector


5.5 District heating networkswith woodchip systems

District heating networks with wood-firedboilers offer tremendous opportunities forthe fast expansion of wood in the heatingsector. In this scenario, wood covers thebaseload, with a gas or oil boiler coveringpeak demand on cold days.14

For example, a heating centre with both awood and an oil boiler were installed in anew residential area with 100 single-familyhomes. The wood boiler was dimensionedto cover heating demand on a normal winterday. When extreme cold fronts comethrough, the oil boiler is switched on tocover peak demand. The wood is deliveredas chips some 5–10cm long. These chips areautomatically fed into the boiler by means ofa screw conveyor. A 50m3 silo can containenough fuel for around a week. The districtheating network has well insulated lines totransport heat from the heating centre tohomes, where it is passed on to heatingsystems and hot water tanks via heatexchangers.

EmissionsWhen we compare heating systems, emis-sions that occurred during fuel extraction,processing, and transport have to be takeninto consideration. If we consider a wood-supported district heating network (with anoil/gas oil boiler for peak demand), we getthe holistic values shown in the chart to theright.15

Because the impact of various types of pollu-tion is not always comparable, the limitvalues in German law (TA-Luft) wereweighted and then added up in line with theprinciple that a pollutant has a lower limitvalue the more toxic it is. This approachallows us to approximate a comparison of

emissions from various heating systems (seeFigure 5.5). Here, wood heating systemsperform worse than oil and gas heaters interms of pollution.

However, would heaters perform far betterin terms of carbon emissions. Indeed, thecarbon emissions from the system with awood heater mainly come from the oil-firedboiler that covers peak demand. A look atthe absolute amounts shows how muchbetter wood performs. While the gas-firedheating system emitted 2.5 fewer tons ofpollution, it also produced 202 tons moreCO2 than the wood-fired heating systemdid!

Recent discussions about particulate matterhave also brought wood stoves back into thespotlight. There can be no doubt that wood-fired heating systems give off smoke – andhence particulate matter. However, the dataused in such debates often pertain to openfireplaces and outdated equipment, notmodern, low-emission wood stoves. Thesemodern systems actually have lower particu-late emissions than normal oil heaters whenrunning full blast with standard wood as afuel. And while emissions do increase whenthe system is running at partial capacity, abuffer tank can be used to reduce emis-sions.16 Finally, electric filters can be used toreduce particulate matter from woodchipsystems.

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Figure 5.5 District heating systems with woodchip heaters: A comparison on emissions

Source: Forstabsatzfonds, Holzenergie für Kommunen, Bonn 2003

Toxic emissions (weighted) in kg/year

Distributedgas heating

Distributedoil heating

District heat fromwood-fired system*

Distributedgas heating

Distributedoil heating

District heat fromwood-fired system*

3,500

3,000

2,500

2,000

1,500

1,000

500

0

700,000

600,000

500,000

400,000

300,000

200,000

100,000

0

kg/a CO2 equivalent

* Wood heater and oil boiler for peak demand


5.6 Energy crops

The previous sections focused on thebiomass created as a byproduct or wasteproduct in agriculture and forestry. But in thepast few years, dedicated energy crops haveincreasingly been planted.

Various types of plants can be used to ‘growenergy’, particularly lignocellulosic plants,which contain large amounts of energy-richcompounds of lignin and cellulose. Examplesof such plants include trees (such as poplarsand willows) and grasses (grains andsubtropical grasses like miscanthus). In theGerman climate, the energy yield rangesfrom 85–425 gigajoules (roughly2400–12,000 litres of oil) per hectare eachyear depending on the type of plant, solarconditions and specific location. But otheraspects also have to be taken into consider-ation, such as labour, insecticides andfungicides, and water demand. In light of allthese variables, there is no single idealenergy plant.17

The example of miscanthus in Germany illus-trates how complex the issue is. A relative ofsugarcane, this plant can produce richharvests per hectare, which led to highexpectations a decade ago in Germany.18 Butthe results have been sobering. Some 20–25tons of dry mass can be harvested perhectare in Germany on good soil, but it turnsout that miscanthus plantations are labour-intensive. Furthermore, the plant does notreact well to bad weather. At present, thehype has largely died down around miscant-hus. Recent research tends to focus more ongrain, corn and fast-growing trees andshrubs.19

Low energy density places one other generallimit on energy crops. For biomass tobecome competitive, transport costs have tobe low. That generally means that planta-tions have to be relatively close toconsumers. Long-range transport of biomassgenerally only makes sense if an energy-richconcentrate, such as oil or biofuels, is madeout of the original biomass.

High oil prices in recent years have broughtmore attention to energy crops. The nega-tive effects of such plantations has alsocome into the foreground, which is whyenergy crops are limited both in Germanyand in the EU (see 5.10):

• The environmental impact from energycrops can be even greater than theimpact from conventional agriculture.For instance, if corn is planted as anenergy crop, it impacts the regionalwater balance and leads to greater soilerosion than plantations of green wood.And if large monocultures of energyplants are planted on unused farmland,biodiversity is reduced because there arefewer wild areas.

• In Germany and the EU, energy cropsdirectly compete with crops for foodproduction. Whatever brings in the mostmoney is planted. As oil prices rise, thepressure to replace food crops withenergy crops will only increase. As aresult, more food will have to beimported. Our demand for energy willthen conflict with demand for foodamong the poor in developing andindustrializing countries. We hardly needto ask whether a well-to-do Mercedesdriver or a Bolivian miner will win out.

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Figure 5.6 The potential energy yield of different energy crops in Germany

Source: Lewandowski and Kaltschmitt, 1998

Dry mass yieldTons per hectare/year

Energy yieldindicated in litres of heating

oil per hectare/year

25

20

15

10

5

0

12,000

9,600

7,200

4,800

2,400

0

Fast-growing

plantations(willows and

poplars)

Wintergrains

(triticaleand rye)

Domesticfeed

grasses

Subtropicalgrasses

(miscanthus)


5.7 Fuel from the field –biodiesel

In Germany, roughly a quarter of all energyconsumption takes place in the transportsector. Our solar energy supply offers anumber of options. Biogas can be producedand used as a fuel just as natural gas is.Entire urban bus fleets are already doing soin Sweden.20 Solar hydrogen can also beused in mobile fuel cells (see 8.5). But by farthe most common option today in Germanyis biodiesel, which can be used withoutmajor revamping of vehicles and infrastruc-ture (petrol stations, etc.).21

Biodiesel is generally made from rapeseed inGermany, which is currently planted on morethan 700,000 hectares.22 The fruit of theplant is first pressed to extract the oil. The‘rapeseed cake’ left behind can be used tofeed animals. The straw from the rest of theplant is returned to the soil as fertilizer.

Rapeseed oil (similar to canola in NorthAmerica) can be used as a pure fuel in refit-ted diesel engines, which is commonly donein trucks and agricultural vehicles.23 If rape-seed oil is esterified, the result is rapeseed-oilmethyl ester (RME), commonly known asbiodiesel. This renewable fuel can be used inalmost any diesel engine, the most promi-nent of which is probably the Germanparliament building in Berlin, which receivesheat and power from a cogeneration unitthat runs on biodiesel.

Up to 2006, fuels made from biomass wereexempt from the tax on mineral oil inGermany. Politicians did so to provide anincentive for renewable fuels.24 As a result ofthis tax exemption and rising oil prices(themselves partly due to greater taxation ofgasoline and diesel), biodiesel sales boomedin Germany. Plantations of rapeseed became

a common sight, and refinery capacityexceeded 2 million tons in 2006. From 1998to 2005, sales skyrocketed from 0.1–1.8million tons.25 But this trend came to anabrupt end in 2006, when biodiesel lost itstax exemption.

Biodiesel has a number of positive effects onthe environment. For instance, finite fossilresources are offset, and sulfur dioxide emis-sions are also lower. Unlike mineral oil,biodiesel decomposes quickly in the environ-ment without causing any environmentaldamage. Biodiesel also performs well whenit comes to carbon emissions, which areroughly two thirds lower than those of diesel– a figure that rises even further when purerapeseed oil is used.26

Roughly half of the rapeseed plantations forbiodiesel are on land set aside by the EU.Farmers can thus decide whether to leavethe land fallow or produce energy crops. Butthere is a ceiling on energy crops, and theallotment has almost been exhausted.Experts believe that biodiesel made inGermany will only be able to cover around70 per cent of the diesel market by 2015(2005: 5.5 per cent).27

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Figure 5.7 A comparison of alternative fuels and conventional systems

Source: Authors’ depiction based on Shell PKW-Szenarien, 1998

Electricvehicles hydrogen biodiesel natural gas

Vehicle technology

Sales/handling

Safety

Taking time

Range

Lubrication

Availability

Costs (vehicle + fuel)

Note limitations compared toconventional drive

low restrictionsrestrictionsconsiderable restrictions

-- -- -- -- -- --

-- -- ---- --

--

---- ---- --

-- -- --

--

--

-- -- --

-- -- --

-- -- --

-- -- --

-- --

-- --

-- -- -- --

-- ----

---- -- --

--

---- --

�

� � �

�

� �

��

�

�


5.8 Fuel from the plantation –ethanol

Roughly 51 per cent of the liquid fuelconsumed in Germany for transport is diesel,with gasoline making up 45 per cent. Thereis a renewable alternative for gasoline aswell. Ethanol (industrial alcohol) can bemade from sugar beets or wheat (starch)and used as a fuel in gasoline engines. InGermany, ethanol is hardly used (3 per centof fuel consumption, mainly blended in28),but Brazil and the US have much longerexperience with alcohol as fuel.

After the first oil crisis, Brazil launched itsPROÁLCOOL Programme in 1975.29 Becauseoil prices were high and sugar prices low,large plantations of sugarcane were used toproduce ethanol for the transport sector.Since the end of the 1980s, Brazil has beenproducing some 11–13 billion litres ofethanol per year. In 2005, productionincreased to 16.5 billion litres, equivalent to45 per cent of global ethanol production. Atpresent, Brazil covers 12–15 per cent of itsnational fuel consumption with ethanol inaddition to exporting large amounts toChina, Japan and the US.

Initially, ethanol was used in a mixture withgasoline at concentrations of up to 25 percent in Brazil. At such concentrations,engines do not have to be changed. In 1979,the first cars running on 100 per centethanol went on sale, and they have sincemade up as much as 90 per cent of all newcar sales in some years. Since 2003, flex-fuelvehicles (FSV) have been made in Brazil; theycan run on any mixture of gasoline andethanol.30

Brazilian ethanol from sugarcane has aclearly positive energy balance and impacton the climate. The fuel contains more than

eight times more energy than was investedin it, and 150–220kg of CO2-equivalent isoffset per ton of sugarcane through thesubstitution of gasoline.31 These values aremuch better than for the ethanol made fromgrain and sugar beets in Germany (seeFigure 5.8), which is why Brazil exports a lotof ethanol to Europa – some 1.4 billion litresin 2008.32

To promote ethanol, Brazil does not chargeany mineral oil tax, and value-added tax(VAT) is reduced. Middle class car driversmainly benefit from these subsidies, whichamount to around US$2 billion per year. At2007 oil prices, Brazilian ethanol wascompetitive with petrol.

Sugarcane for the production of ethanolcovers some 2 million hectares, roughly 3.5per cent of Brazil’s agricultural land. Thecountry is currently considering an expan-sion of ethanol production to cover 10 percent of all agricultural land. While sugarcanecan easily be grown on underused pastures,there are also plans to have sugarcane plan-tations in sensitive ecosystems, such asswamps in flood zones in the Pantanal.Here, the general problem that biofuels facebecomes clear: if a considerable share of thefuel we consume is to come from biomass,large plantations will be needed.33 The extraland needed will either have to come at theexpense of food production, which willdetrimentally affect countries already suffer-ing from malnutrition, or monocultures willreduce biodiversity. The only way to solvethis conflict is to reduce fuel consumption bytraveling less and becoming more efficient.

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Figure 5.8 The energy payback of various fuels

Source: Authors’ depiction based on Ifeu, 2005

Primary energy savings per hectare in GJ/ha per year

Ethanol

Biodiesel

Vegetable oil

from

sug

arca

ne

from

sug

ar b

eets

from

whe

at

from

sun

flow

ers

from

rap

esee

d

from

rap

esee

d

150

100

50

0


5.9 Synthetic fuels (BTL)

Synthetic fuels made from biomass are arecent development. At present, there areonly research and pilot systems.Nonetheless, hopes are high for biomass-to-liquid (BTL, also known as synfuel andsunfuel) fuels. A wide range of biomass –from wood to straw and other energy crops– is converted into a synthetic gas, fromwhich methanol or a fuel similar to diesel ismade.34 The process is similar to Fischer-Tropsch synthesis. Such procedures are wellknown in the chemical industry. What is newabout BTL production is the use of biomassas the precursor; a number of problemstherefore still have to be solved. On the onehand, vegetable material is more heteroge-nous than oil and natural gas; on the other,the low energy density and distributedproduction of biomass mean that storageand transport have to be optimized (see5.6).

The largest pilot unit for BTL fuel (Sundiesel)was inaugurated in 2008 in Freiberg,Germany. The plant, owned by Choren,which is partnered with car companies VWand Daimler and the Shell oil company,produces BTL fuel from any kind of biomass,such as wood chips, straw, weeds or leftovermilk rejected by the agrofood industry. Theplan is to have the plant produce 18 millionlitres of Choren’s Carbo-V (a type ofbiodiesel).

Two specific benefits are expected from BTLfuel:35

1 Cars are increasingly expected to havelower emissions and better gas mileage.Such engines need fuels with propertiesthat fall into an increasingly narrowwindow. The properties of rapeseed oilfluctuate slightly depending on thequality of the material used, so it seemsclear that rapeseed oil will not be able tocomply with the Euro 5 standard. But thehope is that synthetic fuels will betailored to the requirements of specificengines in order to reduce emissions andmake engines more efficient.

2 A wider range of plants can be used tomake BTL fuels than to make otherbiofuels (see 5.7 and 5.8),36 and theentire plant can be used, not only thefruit. The energy yield is thus higher.Nearly 4000 litres of fuel can beproduced from a hectare, roughly twiceas much as with biodiesel (see Figure5.9).

On the other hand, the use of the entireplant also has a drawback; because no nutri-ents are returned to the soil, fertilizer has tobe used, which raises the energy input. Thehumic content and overall productivity ofthe soil can be drastically altered. Here,sustainable agriculture is a must, and wemust be careful not to quickly assume thatBTL will be the biofuel of the future.

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Figure 5.9 How much a hectare can produce

Source: Spiegel Special 5/2006, authors’ depiction

Range in kilometres per hectare with gasmileage at 5 l/100km (47.04mpg)

100,000

80,000

60,000

40,000

20,000

0

BiodieselEthanol

BTL

Biogas


5.10 Is there enough land forbiofuels?

Expanding the production of biomass andbiofuels in particular would require tremen-dous amounts of land – land that is notavailable in unlimited quantities either inGermany or elsewhere. At the same time,land is needed to produce food. As greateramounts of land are devoted to the produc-tion of biomass for energy purposes,conflicts are therefore inevitable. The figuresbelow make that clear:

Worldwide, some 50 million square kilome-tres were available for agriculture in 2000,equivalent to 8200m2 per person. Most ofthis land is used extensively, however, suchas grasslands in Argentina. Only around 15million square kilometres, roughly 2500m2

per person, is used intensively. This figurewill drop, however, as growing populationsovertake production increases. By 2030, only1900m2 of farmland will be available perperson.37 Residents of EU-15 already make agreater than average use of their land andeven import food and animal fodder,thereby taking up large tracts of land inAfrica and Latin America.38 Imports of biofu-els to fulfill the EU’s 20 per cent target by2020 would increase the land needed by17–38 per cent, roughly bringing us up tothree times the area available per person(see Figure 5.10).39

Clearly, the EU will not be able to make dowith its own land and will therefore requireland abroad. The danger is that energy cropplantations will expand intensive agriculturalland, leading to further clear-cutting of rain-forest as can be seen today in Brazil andMalaysia, for example.40 Furthermore, thereis a danger that these countries will rededi-cate land previously used for domestic needin order to produce biomass for export,

which would endanger the livelihood of thelocal rural population. At the same time, wehave to ensure that the use of pesticides andmineral fertilizers is not used to createmonocultures in order to increase biomassyield. The ecological impact would betremendous. Internationally traded biomasstherefore needs to be certified based onecological and social aspects to take accountof these risks.

Crop rotations and combinations thatensure biodiversity along with greaterharvests provide opportunities for a supplyof biomass,41 and new energy crops that donot change ecosystems much can also playan important role. For example, jatropha, aplant usually used as a hedge in Africa, canproduce an oil that can be used in dieselengines. Tests are currently being conductedin India with the plant, which grows onextremely poor soil and nonetheless hassignificant oil production.

In addition to our current mobility, we alsohave to take a closer look at our eatinghabits. Meat production requires largeamounts of fodder and is one of the mainreasons why EU citizens require so muchland. By changing our diets, we can make dowith less land. Otherwise, we face a bleakalternative – steak on your plate or biofuelsin your tank.42

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Figure 5.10 Fuels from biomass take up a lot of land

Source: Authors’ depiction based on Bringezu and Steyer, 2005

Agricultural land available per personon the Earth in m2

Global population is expected to rise to 8.3 billion by2030, which will reduce the average amount of

agricultural land available per capita.

Available meadowsand naturalgrasslands

Area per EU-15 citizenfor food crops

Area per EU-15citizen for food andfuels (18 per centbiomass)

Available croplandand permanent

cultures

10,000

8,000

6,000

4,000

2,000

0

Outside the EU Within the EU


6.1 Wind power comes of age

Back in 1900, some 18,000 traditional wind-mills were still in operation in Germany. Theywere mainly used to produce flour. But overthe decades, they were gradually replacedby electrical equipment. In the 1980s,modern wind power began. These windturbines are no longer mechanical windmills,but rather power generators. In Germany,the new age of wind power started off witha disaster. In the Growian project, theGerman Ministry of Research andTechnology wanted to set a new record. TheGrowian wind turbine had a rated output of3MW, some 55 times larger than the biggestserially produced wind turbines back thenand six times bigger than the largest testwind turbine in Denmark – and Germanengineers did not have nearly as much expe-rience as their Danish colleagues. Growianwas quickly decommissioned because oftechnical problems.

In the 1980s, Denmark retained its pioneer-ing position in the field of wind power, butin the 1990s the German wind powermarket boomed. It all got started in 1989with a government programme entitled‘250MW Wind’, but in 1990 the ball reallygot rolling when feed-in tariffs were offeredfor wind power starting in December (see11.9). Two-figure growth rates becamecommon and further technical developmentproduced ever larger wind turbines. At theend of the 1980s, 50kW was a largemachine, and 250–300kW was state-of-the-art at the beginning of the 1990s.Nowadays, large wind turbines generallyhave outputs exceeding 1MW, and 2MW isnothing unusual. The largest standardturbines on offer have 5MW, and tests are

currently being conducted on even largerunits.

The economic situation for wind power hasimproved considerably along with the tech-nical developments that produced largerturbines. Since 1990, the price of windpower has been cut roughly in half.1

And although units larger than 2MW couldnot currently offer any specific cost benefits,they do allow more wind power to beharvested from a given plot of land, therebyreducing the amount of land needed.

The future of wind power will largelydepend on two further developments:repowering i.e. replacing small windturbines with larger ones; and offshore windfarms (see 6.7).

The potential for onshore wind is estimatedat 45–65 terawatt-hours (TWh) per year inGermany alone. The offshore potential inGermany is estimated at 110TWh, roughly aquarter of annual German power consump-tion.2

6

6 Wind Power


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Figure 6.1 Wind power takes off: The performance of wind turbines increases

Source: The authors; DEWI

Average output per installedwind turbine in kW

2,000

1,500

1,000

500

01993 1995 1997 1999 2001 2003 2005 2006 2008 2009


6.2 Wind power and natureconservation

H.C. Binswanger, the former director of theInstitute of Economics and Ecology at SaintGallen College in Switzerland, wrote severalyears ago calling wind power ‘the wrongalternative’. The main problem he has withwind power is ‘visual emissions’ and thenegative impact of wind farms ‘when windturbines are a blight on entire landscapes’.He writes that he is ‘mainly concerned aboutprotecting our cultural landscape, which ispredominantly characterized by multifariousfarmland and pastures that arrived at theircurrent unmistakable form over long periodsof slow growth’.3 Binswanger says there is arisk that these cultural landscapes will beturned into large tracts of ‘technologicalparks’.

The Swiss professor is not alone in opposingwind power.4 For instance, the GermanAssociation for Landscape Protection isfrequently on-site whenever there areprotests against a wind turbine. They agreewith Binswanger that wind power destroyslandscapes without making any considerabledifference in our energy supply.

There can be no doubt that wind turbineschange landscapes. But the effects can bekept to a minimum with proper planningand citing. Furthermore, relatively little landis used.5 Aside from the foundations (andpossibly access roads and transformers), thesoil remains unchanged and can still be usedin agriculture.

And of course, taste is a matter of opinion.While wind turbines may be a thorn in theside of some people, others may see them asfascinating symbols of progress. Moreimportantly, opponents of wind powershould say why they do not oppose our

conventional energy supply system, whichhas a far greater impact on our landscapes.For instance, in a distributed supply ofrenewable power, we could do away withsome of the approximately 200,000 high-voltage power pylons in Germany. And ofcourse, coal mining destroys entire land-scapes into moonscapes and destroys towns.Yet, a wind turbine with an output of1.5MW and a service life of around 20 yearswill offset some 80,000 tons of brown coal.6

Wind power opponents are demonstrablywrong in their estimation of the potential ofwind power. For instance, Binswanger oncebelieved that only 5000MW of wind powerwas possible in Germany; unfortunately forhim, 10,000MW had already been installedby 2002, and the 25,000MW threshold wascrossed in 2009. Wind power will coversome 20–30 per cent of power consumptionin Germany by around 2025. And thattarget could be reached even faster if powerconsumption were reduced through effi-ciency and conservation.

If your goal is long-term nature conservationand protection of the biosphere with asustainable energy supply, you simply mayhave to accept some minor changes tocultural landscapes. And if you can, then youjoin the ranks of such organizations asFriends of the Earth, Greenpeace, the WorldWide Fund for Nature and Robin Wood, allof whom support the environmentallyfriendly expansion of wind power.

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Figure 6.2 Wind power and landscape conservation

Source: The authors

At a good location, a 1.5MW wind turbine with a hub height of 67m willproduce some 76 million kilowatt-hours of electricity over 20 years ofoperation. To produce the same amount of power in a modern browncoal plant, some 84,000 tons of brown coal would have to be fired. If thatamount of coal were piled up, the pile would be 50m tall and have adiameter at the base of 80m.


6.3 Wind velocity is key

Wind turbines have basically four opera-tional phases. When the wind is not blowingenough to overcome the turbine’s frictionalresistance, the turbine does not move. Whenwind velocities reach around 3m per second(around 10km per hour), the turbine beginsto turn and generate electricity. As windvelocities increase, the turbine’s outputincreases until it reaches the generator’snominal output – the maximum amount ofpower it can produce. As wind velocitiesincrease even further, the excess power hasto be done away with. Generally, the rotorwings are either specially designed to do so,or they can be pitched out of the windmechanically. Finally, in storms (wind veloci-ties of 20–25m per second upwards), theturbine switches off automatically to preventdamage.

The average amount of power produced bywind turbine installed in Germany is around1800kWh per kilowatt of installed capacity.7

Regionally, though, values differ. On thecoast of the North Sea, power output isroughly 13 per cent greater than theGerman average, while it is 10 per centbelow average in Rhineland-Palatinate.Wind turbines at high altitudes can,however, perform as well as turbines on thecoast.

The main reason for different annualperformances is different wind velocities andfrequencies from one region to another.Average wind velocity is the main factor in awind turbine’s output. Generally, greaterwind velocity increases the power output bya power of three.

In other words, if the output of the windturbine is 100 per cent at 10m per second,that turbine does not produce 10 per centmore power under a wind velocity of 11mper second, but instead roughly 33 per centmore – (1.1)3 = 1331. Put differently, 10 percent more wind velocity means a third morewind power.

When siting wind turbines in hilly regions,this fact is crucial. Often, nature conserva-tion proponents claim that a wind turbineon top of a hill would be a blight on thelandscape; they therefore require the turbineto be located on a slope. Yet, wind velocitiesare generally higher at peaks. The differencefor wind power can be severe. For instance,if an average wind velocity at the peak is6.5m per second over the year compared to4.5m per second on a slope lower down, thedifference is around 30 per cent, which maynot seem crucial to a layperson. But, in fact,the wind turbine will produce more than 65per cent less power, making the turbinelower down the hill unprofitable. And, if youwant to build it anyway, you would need toput up three turbines on the slope to get thesame power that a single turbine on top ofthe hill would produce. On the one hand,that option is an inefficient use of resources;on the other, defenders of landscapesshould decide whether they want to have asingle turbine in a good location or threeturbines on suboptimal locations.

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Figure 6.3 Wind velocity is crucial

Source: The authors

A wind turbine at a wind velocity of 6.5m/s

generates the same amount of electricity as

three wind turbines at a velocity of 4.5m/s

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6.4 The success story of windpower since the 1990s

To see what opportunities the Solar Ageoffers to industry and trades, we need lookno further than the history of wind power inDenmark. While the wind energy markethad hardly gotten underway in Germany bythe end of the 1980s, Denmark had alreadyinstituted a number of policy instrumentswith clear targets.8 A dedicated research anddevelopment programme along with feed-inrates and clear guidelines to export windpower to the grid allowed a new market tobe created. As a result, a booming windindustry was set up in Denmark within onlya few years. The Danish industry became theworld’s main manufacturer and exporter ofwind turbines.

With some delay, Germany became thecountry with the most installed capacity ofwind turbines until it was overtaken by theUS in 2008. In 2002 alone, some 3200MWwas newly installed. By the end of 2009,more than 21,000 wind turbines with a totalrated output of around 25,700MW hadbeen installed. In 2004, wind power over-took hydropower as the largest source ofrenewable energy in Germany. 9

Manufacturers of wind turbines, suppliers,and wind power project planners havecreated some 85,000 jobs in the past fewyears,10 many of them in small and midsizeenterprises. The wind sector is now thesecond largest purchaser of German steelafter the automotive industry.11

The positive experience gained with policiesto support wind power can be applied toother renewable technologies, though thefocus need not be on applying the samerates with the exact same policy designs.Rather, the goal should be to develop amixture of policies tailored to each technol-ogy and field of application so that thecurrent roadblocks in the implementation ofefficient, environmentally friendly technolo-gies can be overcome (see 11.18).

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Figure 6.4 The success story of wind power: Trends in Germany since the 1990s

Source: The authors; DEWI

Installed wind power capacity in MW

Year

25,000

20,000

15,000

10,000

5,000

01991 1993 1995 1997 1999 2001 2003 2005 2006 2008 2009


6.5 The success story of windpower – the advantage ofbeing first

Internationally, the wind sector has alsoboomed in the past few years. In 2004alone, 8154MW of turbines were installed,12

a 20 per cent increase on the previous year.In addition to European markets, markets inAsia and the US grew the fastest.

German manufacturers used to concentrateon their domestic market, which was thelargest in the world for wind turbines at theturn of the millennium. They had a verygood market position back then; theyinstalled some 2100MW in 2001. Butexports were few and far between for them.Only 14 per cent of the global marketoutside of Germany went to German manu-facturers (3805MW). In terms of newlyinstalled capacity within Germany, theexport quota of German manufacturers was16.4 per cent in 2001.13 In contrast, the fourbiggest Danish manufacturers exportedaround 3000MW of wind turbines in 2001,five times as much as their German competi-tors14 (see Figure 6.5).

The situation has changed considerablysince then. German wind turbine manufac-turers are now among the global leaders.And exports make up a large part of theirsales. In 2005, more than 60 per cent ofGerman production was exported,15 ensur-ing approximately 30,000–40,000 jobs.

One reason for the disparity in exportsbetween Germany and Denmark was theadvantage that Danish firms had up to themid-1990s in technology development;these firms had helped develop foreignmarkets and were therefore better posi-tioned in them. Furthermore, Germanmanufacturers were not as interested inforeign markets up to 2003 because theirown home market was growing so quickly.They therefore focused on meeting domesticdemand.

Being a pioneer in the development androllout of technologies – the first mover –offers considerable economic advantages forindustry and trades. A technological edgestrengthens your position in internationalmarkets and increases export opportunities.In addition, first movers can also help maketheir domestic markets independent.

But if you want to conquer export markets,the example of Denmark shows that youfirst need to set up your own domesticmarket.

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Figure 6.5 The success story of wind power: The importance of being a first mover

Source: Authors’ depiction based on DEWI

The share of exports in overall production amongDanish and German manufacturers in 2001

Installed wind turbine capacity in megawatts in 2001

3,500

3,000

2,500

2,000

1,500

1,000

500

0

Danishmanufacturers

Germanmanufacturers

In 2001, Denmark was the leader in wind turbinesfor export, but German manufacturers have caught

up in the meantime.

Exportmarket

Domesticmarket


6.6 Wind power worldwide

Worldwide, installed wind capacity grewfrom just under 20,000MW at the beginningof 2001 to around 158,000 megawatts atthe end of 2009. Within eight years,installed capacity grew eightfold.16

The main markets in 2009 were China witharound 13 GW, the US with 10GW, Spainwith 2,5GW and Germany with 1,9GW.

In 2008, the US overtook Germany, whichhad had the most installed wind powercapacity for several years. At the end of2009, the US still led the pack with35,170MW. Germany came in second with25,770MW just ahead of China at25,104MW.17

The greatest growth is currently taking placein the US and China. Thanks to the Obamaadministration’s stimulus package, the USwind industry installed 9.9GW in 2009 after8.4GW in the previous year.18 China installed6.3GW in 2008 followed by 13GW in 2009.Spain was the leading European country in2009 in terms of newly installed wind powerat 2459MW, ahead of Germany (1917MW).Much less was invested in Italy (1114MW),France (1088 MW) and the UK (1077 MW).

Wind power has also become big business ina number of emerging nations, such asIndia. After a number of already impressiveyears, installed capacity rose by 23 per centin 2008 and 13 per cent in 2009. Most ofthe demand comes from industry, which islooking for an alternative to conventionalpower suppliers. Here, high oil prices arealso a main driver behind the wind powerboom. As long as the price of a barrel of oildoes not drop below US$40, wind turbinesare cheaper according to the CEO of Indianwind turbine manufacturer Suzlon.19 Suzlonis a solely Indian firm that has grown quicklyalong with the Indian wind market. In thepast few years, the company has also set upproduction plants in the US and China, andovertaken German wind turbine manufac-turer Repower.

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Figure 6.6 The installed capacity of wind turbines worldwide

Source: World Wind Energy Association

MW

160,000

140,000

120,000

100,000

80,000

60,000

40,000

20,000

0

Africa and South/Central America

Asia and Oceania

North America

Europe

1995 1997 1999 2001 2003 2005 2007 2009


6.7 Wind power prospects –offshore turbines

Offshore turbines have two major advan-tages over onshore technology:

• The energy yield per installed capacityunit is much higher. Wind velocities arehigher, and the wind also blows moreoften because of the lack of obstacles. Inthe North Sea, the average annual windvelocity at a height of 60m ranges from7–10m per second, compared to 8m persecond in the Baltic Sea.

• Because the area is generally availablefor use, it is easier to set up large windfarms offshore than it is on land. At adistance of more than 10km off thecoast, such wind farms are hard to seefrom shore and no noise can be heard.

But there are also disadvantages:

• Foundations for offshore turbines aremuch more complicated and can beextremely costly depending on the depthof the water (up to 40m).

• Grid connections for such wind farmsare also a major cost factor. The furtherthe turbines are away from the coast,and the smaller the wind farm, the morethese costs will play a role. Generally, thelargest turbines available (usually largerthan 2MW) are used offshore, and suchfarms have a large number of turbines.

• Finally, maintenance and servicing costsare still hard to calculate. The turbinesrun more often and the salty sea airincreases the need for anti-corrosion. Wewill, however, soon know whether suchoffshore projects pay for themselvesmore than wind farms in good locationson the coast.20 Whatever the case,offshore wind certainly provides a majorincentive for the development of larger,more powerful wind turbines.

A number of offshore farms have alreadygone up in Denmark, Sweden, TheNetherlands and the UK.21 All of them arerelatively close to the coast and in relativelyshallow water.22 By the end of 2008, some1.5GW of offshore wind turbines had beeninstalled, most of them in Europe.

Plans for offshore wind farms have beendelayed in Germany for several reasons.First, approval procedures have taken longerthan expected. Second, the question of whocovers the cost of grid connections and gridexpansion was not yet clear. Third, investorswere not certain that the feed-in ratesoffered for offshore wind power wouldprovide a return in light of the higher costs.In 2010 the first German offshore wind parkwas connected to the grid.

The grid will have to be expanded consider-ably for wind power, especially offshorewind. Germany’s Network Agency hasproduced a study23 on what Germany wouldneed and is currently completing a follow-up.24

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Figure 6.7 Tremendous potential for offshore wind

Source: VESTAS

Wind power in shallow seawater:

great expenses, but also great returns


6.8 Wind power prospects – lessis more through repowering

Repowering means replacing small, oldturbines with new, more powerful and moreefficient ones.

Wind turbines have an expected service lifeof 20 years, but the technology has devel-oped so much over the past two decadesthat wind turbines can seem outdated eventhough they may still be running. Forinstance, in 1995 the average turbine newlyinstalled in Germany had an output of lessthan 500kW; by 2008, it was around 2MW.Larger turbines with taller towers couldmake better use of wind and run at highercapacity. The energy yield of modern windturbines has thus been growing faster thantheir rated capacity. As a result, it would bepossible to produce even more power withina given plot of land if old turbines arereplaced by larger – and more efficient –new ones. The rule of thumb is ‘twice theoutput from half as many turbines’.

The greater power yield comes from theturbine’s greater output (longer, more effi-cient wings, higher nacelles) and fromgreater availability.

Repowering is a political goal. Since theGerman Renewable Energy Act was revisedin 2004, special financial incentives havebeen provided to replace inefficient oldturbines that are nonetheless still runningproperly.

However, a number of obstacles prevent orslow down repowering. For instance, theState of Lower Saxony recommends that itscommunities only install new turbines atleast 1000m from the nearest home.25 OtherGerman states have similar stipulations.Furthermore, some communities do not

allow turbines taller than 100m to be set up,which practically rules out turbines with2MW or more.

Such height and distance limits not onlyseverely restrict the expansion of windenergy, but also ensure that the impact onthe landscape is greater than necessary.After all, repowering allows the number ofturbines installed to be reduced. Forinstance, in a project in northern Germany(see Figure 6.8) three five-megawattturbines could replace eleven 500kWmachines26 even as the overall annual outputis tripled.

Repowering has been going slowly inGermany. In 2005, only six wind turbineswere renewed. The revised RenewableEnergy Act of October 2008 provided betterfinancial terms for repowering. The successof this new law is already clear. While some24MW was repowered in 2008, the figurehad risen to 136MW in 2009. As thePresident of the German Wind EnergyAssociation (BWE) put it: ‘Germany has a lotof wind energy potential in repowering overthe next few years.’27

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Figure 6.8 Repowering: Less is more

Source: Bundersverband Windenergie, 2005

Simonsberg wind farm Before After Multiplier

Number of turbines 11 3 0.27

Hub height (x metres) 42m 120m 2.86

Rated output of individual turbines 500kW 5,000kW 10.0

Total installed capacity 5.5MW 15MW 2.72

Full capacity hours 2,545 3,200h/a 1.26

Annual power production 14 Million kWh 48 Million kWh 3.43

Before

After


7.1 Water power – the largestsource of renewable energy

Solar energy keeps water circulating on theEarth. Worldwide, more than 50 billion cubicmetres of water evaporates each hour, mostof it over the oceans. When this water fallsonto land as precipitation, the difference inaltitude between the land and sea levelprovides useful energy potential.

Water power is one of the oldest sources ofenergy used by mankind. In around 3500BC, water mills were used in Mesopotamiato irrigate the land. And around 100 BC,water mills were used to grind grain anddrive sawmills in the Roman Empire. Today,the kinetic energy in water is mainly used togenerate electricity. The process is as easy asit is efficient; water flowing downhill drives awaterwheel or a turbine, which generateselectricity. Depending on the amount ofwater and the difference in altitude, differ-ent types of turbines are used,1 with theaverage efficiency being quite high at 90 percent. Hydropower has one advantage overwind power and photovoltaics: it is relativelyconstant and can be stored easily. As aresult, a number of hydropower plants canbe used to provide baseload power. Andwater stored in lakes can also be sentthrough turbines in seconds to provide peakpower. Water power is therefore a very flex-ible source of renewable energy.

Worldwide, hydropower is by far the largestsource of renewable electricity. In 2005,some 2950TWh of hydropower was gener-ated, equivalent to 90 per cent of theelectricity from renewable energy and some16 per cent of all of the electricity generatedworldwide. Hydropower comes in just aheadof nuclear power, which provided 2771TWhin 2005. In some countries, hydropower isthe largest source of domestic electricity, forexample, in Canada (60 per cent), Brazil (84per cent), Switzerland (around 55 per cent),Iceland (around 80 per cent) and Norway(around 98 per cent).2 Iceland and Norwayare also looking into ways to expandhydropower even further in order to providerenewable hydrogen from excess electricity;the hydrogen could then be used as a fuel invehicles, for example (see 8.5).3

Yet, the potential of hydropower has hardlybeen exhausted. Worldwide, it is estimatedthat some 15,000TWh of electricity couldcome from hydropower each year, roughlyequivalent to our current global powerconsumption, though only half of that isconsidered economically feasible.Unfortunately, the potential thathydropower has is not equally distributedacross the globe (see Figure 7.1). Europe andthe US already use a large part of theirpotential, whereas Africa, Asia and SouthAmerica could still expand greatly.4

7

7 Water Power, Geothermal and OtherPerspectives


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Water Power: Geothermal and Other Perspectives

7

Figure 7.1 Water power: Global potential, used and untapped

Source: Landesinitiviative Zukunftenergien NRW: Wasserkraftnutzung

TWh/a

Untapped potential

Potential already used

5,000

4,000

3,000

2,000

1,000

0Africa Asia Europe USA Oceania South/

CentralAmerica

CISstates


7.2 Expanding hydropower –the example of Germany

Hydropower has been used for centuries inGermany. Often, hydropower was the start-ing point for merchants and cottageindustries (mills, pumps, etc.). Starting in themid-19th century, hydropower was used togenerate electricity, and up to 2003 it wasthe largest source of renewable electricity inGermany. Today, hydropower provides some20 billion kilowatt-hours of electricity peryear, roughly 4 per cent of the country’s elec-tricity consumption.

At the same time, hydropower is the onlyrenewable source of energy that has beenlargely exhausted in Germany; roughly 75per cent of its potential is already exploited.The potential for new large hydro dams hasalready been completely used up, thoughcurrent systems can generally be revampedto increase power output considerably.5 Forinstance, the Rheinfelden plant wasmodernized to increase power productionmore than threefold. The power increasedfrom 26MW to 100MW, and the annualpower production, which began in 2010,will grow from 185GWh to 600GWh.6

Micro hydropower units, in contrast, stillhave a lot of potential. The GermanHydropower Association (BDW) of Munichestimates that units with an output of up to5MW could increase the amount of electric-ity from hydropower by around 50 per cent.

Hydropower potential is unevenly distrib-uted across Germany because of thecountry’s typology. The two southernGerman states of Bavaria and Baden-Württemberg have some 75 per cent ofGerman hydropower potential (see Figure7.2), while there is very little potential in thenorth.

Over the past 100 years, some 50,000microhydro units have been decommis-sioned in Germany; in 1850, roughly 70,000such units were still in operation. But often,they did not pay for themselves because therates they received were too low, waterrights were disputed or financing was hardto get for urgently needed repairs. But sincethe Feed-in Act of 1991, the situation ischanging. From 1990 to 1999, the numberof microhydro units that generate electricityincreased from around 4400 to 5600.7 Thesenew systems alone generate some 80 millionkilowatt-hours of environmentally friendlyelectricity, roughly enough to cover thepower consumed by more than 200,000German households.

Reactivating old units is not the only way toincrease the amount of energy fromhydropower. Technical improvements canalso be made to old water wheels andturbines.8 But generally, expanding andincreasing the efficiency of hydropowerunits requires large upfront investments thatonly pay for themselves over long periods oftime.

To expand hydropower further, currentapproval procedures, which are quitecomplicated, need to be simplified, and theright of use for water must be given forgenerous periods of time.

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Figure 7.2 Hydropower in Germany

Source: Kaltschmitt, Wiese. Chart: triolog

Total hydropower potential in Germanyca. 25 TWh/a

BavariaBaden-Württemberg


7.3 Hydropower and natureconservation

There are ecological limits to the expansionof hydropower. One goal of nature conser-vation is to protect natural waterways andwaterways close to nature. This goal canconflict with the use of hydropower; afterall, hydropower units change ecosystems.When permits are granted for hydropowerunits, the individual situation must beassessed exactly. The following must betaken into consideration and weighedagainst the advantages of renewable power:

• Impact on the ecosystems of flowingwater, especially the protection anddevelopment of local flora and faunaboth in the water and on banks.

• Impact on water management, espe-cially flood protection, flow rates andgroundwater.

• Impact on other water functions, such asrecovery rates.

While it is not possible to discuss all of theseaspects comprehensively here, we do discusstwo aspects below:

BarriersRun-of-river dams generally have some kindof barrier or weir that prevents fish frommoving upstream easily, thereby stoppingsome species from returning to parts of theirnatural habitat (for instance, to lay eggs).Fish ladders and fishway bypasses solve theproblem; part of the flowing water isdirected to the side of the dam either oversteps or in some sort of side stream to allowfish to continue up the river.

Minimum water volumeDiversion hydroplants, one of the mostcommon types, take some of the water outof the river and put it through a pipe with aturbine at the end; the water is thenreturned to the river downstream. The wateris therefore temporarily removed from theriver. During the dry season, water levels candrop significantly, creating problems for localflora and fauna. The minimum amount ofwater that has to be in the river is often abone of contention in permitting proce-dures. Nature conservation authorities wantthat minimum amount to be high to protectthe local ecosystem, but plant operatorswant to be able to take a large amount ofwater out of the river to generate (environ-mentally friendly) power. For instance, thefollowing compromise was recently reachedfor a project in Baden-Württemberg: at leasta third of average minimum flow – theamount of water that the river still had at itslowest level on average over the past fewyears – over the year must remain in theriver.

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Figure 7.3 Hydropower and nature conservation: Fish bypasses

Source: Das Wassertriebwerk, 1/2000

Fish ladderand pool-and-weir stream


7.4 The world’s largesthydropower plants

While Rheinfelden is considered a largehydropower plant by German standards, atonly 100MW megawatts, it is quite small ona global scale. Worldwide, somehydropower plants are true giants.9

The Itaipú dam on the border between Braziland Paraguay was constructed on theIguaçu and Paraná Rivers. A storage lakesome 170km long – roughly twice as largeas Europe’s Lake Constance – was createdbehind a dam 196m tall and 7.8km long.The power plant has a capacity of 12.6GWand generates around 95,000GWh of elec-tricity each year, roughly enough to cover aquarter of Brazil’s power demand – or theo-retically a sixth of Germany’s.

For a long time, this hydropower plant,which went into operation in 1983, was thelargest in the world, but in May 2006, theThree Gorges Dam on the Yangtze Rivertook that title. At 185m tall and 2.3km long,this dam is justifiably nicknamed the NewGreat Wall of China. Now that all of theturbines have been put into operation, thepower plant has a capacity of 18.2GW,roughly as much as 16 nuclear power plants.

Despite the positive aspects of renewableelectricity and flood prevention, these andother giant hydropower plants have facedsevere criticism.10 For example, the construc-tion of such dams forces millions of peopleto leave their homes and resettle. At theThree Gorges Dam alone, an estimated 1.2to 2 million people had to be relocated.11

Generally, these people do not receiveproper compensation for their losses. Anumber of them, such as fishermen, losetheir means of livelihood altogether. Theecological impact of large storage dams is

also criticized. The flooding of entire valleyscompletely destroys ecosystems, and theflooding of dense forests releases toxicgases.12 Furthermore, the resulting lowerlevels of oxygen in the water detrimentallyaffect fisheries, and the new body of wateraffects the climate. For instance, the sedi-ments carried by the Yangtze River – some680 million tons of sand and mud each year– is gradually filling up the storage lake(which would fill up much quicker if it werenot so deep), and the water below the damlacks sufficient nutrients. In the tropics,storage dams are also a health risk becausethey provide optimal habitats for mosquitoesthat transmit malaria.13

There were reports of widespread corruptionduring the construction of the Three GorgesDam related to apparent fractures and holesin the dam itself – which, it should be noted,was constructed in a region prone to earth-quakes that could destroy the damaltogether. If that happens, millions ofpeople could be flooded.14

In conclusion, most large hydropower plantsnot only produce environmentally friendlyrenewable power, but also have a consider-able social and ecological impact. Thesedrawbacks must be taken into considerationwhen we work to expand hydropower. Itmay often be better to have several smallprojects done instead of one large one.

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Figure 7.4 Giant hydropower: The Three Gorges Dam in China

Source: dpa


7.5 Geothermal worldwide

Unimaginable amounts of energy are storedwithin the Earth. More than 95 per cent ofour planet is hotter than 1000°C. Heat isconstantly flowing to the relatively thin crustof the Earth from its core. The amount ofheat that reaches the surface worldwide isroughly equivalent to 2.5 times our globalenergy consumption. Up to now, most of ithas escaped into space unused. But thisgeothermal heat can be an important part ofour sustainable energy supply. After all, it isavailable around the clock in all seasons,unlike intermittent solar and wind energy. Itcan therefore be used to cover baseloaddemand, making it an important option toreplace nuclear power.

Today, geothermal energy is used in 76countries. Most of these systems are inregions with active volcanoes, where hightemperatures are found not far below thesurface. Geothermal energy can be useddirectly to heat buildings, greenhouses,swimming pools, etc. or as process heat todesiccate produce and fish, produce salt andfor other purposes. Roughly half of the geot-hermal energy currently used comes fromheat pumps, which generally run on electric-ity (see 7.6); some 2 million such heat pumpsare currently used worldwide to heat andcool buildings.15

Geothermal heat can also be used to gener-ate electricity. The first geothermal plant,which had an output of 250kW, went intooperation in 1913 in Lardarello, Italy.16 Today,geothermal power plants worldwide collec-tively have an output of around 9000MW,equivalent to 20 large coal plants. Most ofthem are in the US, especially in California(some 2540MW). In the world’s largest field,the Geyser (1421MW), several power plantscollectively produce as much electricity as a

large nuclear plant.17 Over the past fewyears, the Philippines, Indonesia and Japanhave added a lot of geothermal electricitygenerating capacity, more than doublingtheir overall capacity from 1990 to 2000. InJava, Indonesia, Gunung Salak is installingone of the world’s largest geothermal powerplants (330MW).18 Worldwide, geothermalpower made up some 1.8 per cent of renew-able electricity in 2003.

In Europe, Italy and Iceland are geothermalleaders. Iceland already gets 55 per cent ofits primary energy consumption from geot-hermal energy; 87 per cent of homes thereare supplied with geothermal heat, andgreenhouses and fish farms heated withgeothermal heat helped the country increaseits food production.19 Iceland also gets mostof its electricity from hydro and geothermalplants. In 2004, some 200MW of geother-mal power generation was installed, enoughto cover around 15 per cent of the country’spower supply. In 2008 the installed genera-tion capacity of geothermal power plantstotalled 575MW and the production was4038GWh, or 24.5 per cent of the country’stotal electricity production.20

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Figure 7.5 Geothermal: Installed capacity of a select group of countries

Source: Authors’ depiction based on International Geothermal Association (IGA), 12/2004

Power plant capacity (MWel)

Heat capacity (GWh)

USA

Philippines

Mexico

Indonesia

Italy

Japan

New Zealand

Iceland

USA

Philippines

Mexico

Indonesia

Italy

Japan

New Zealand

Iceland

0 2,000 4,000 6,000 8,000 10,000

0 500 1,000 1,500 2,000 2,500 3,000


7.6 Underground heat

Even in places such as Germany, where thereare no active volcanoes, geothermal heatcan be used. After all, temperatures inEurope increase by around 3°C every 100mbelow ground. This heat can be used invarious ways:

Downhole heat exchangersThe most common way of using geothermalenergy is to heat buildings by using under-ground heat exchangers. Here, twou-shaped tubes serve as a heat exchanger inthe borehole some 100m deep. When wateris injected into this tube, the undergroundheat is absorbed and the water comes backup a few degrees warmer. A heat pump (see8.1) then increases the underground energyto a higher temperature (around 35°C) toprovide low-temperature heat for homes.Outside of the heating season, the heatunderground regenerates through sunlightand heat from ground water and the under-ground.

Hydrothermal systemsAt depths of 1000–2500m, undergroundtemperatures sometimes exceed 100°C evenin parts of Germany. These natural reservoirsof hot water are large sources of geothermalenergy. The water in the aquifer is firstpumped to the surface, where it passes onits heat to a service water system by meansof a heat exchanger. Although the water hasnow cooled down a bit, it still containsenough heat to be used in a heat pump (see8.1), which cools down the water evenfurther by raising the heat taken from it to ahigher level. The water is then injected backinto the aquifer. The heat collected can beused in a district heating network.

Geothermal heating stations are generallypossible wherever there are such thermalaquifers. In Germany, they are mainly foundin the flat lands of the north, in the RhineGraben in the southwest, and in the molassebasin south of the Danube at the foothills ofthe Alps. According to the GeothermalAssociation of Germany (www.geother-mie.de), the thermal aquifers along themolasse basin contain enough heat to coverthe demand for environmentally friendlyheat in three cities the size of Munich.

In the former East Germany, three geother-mal heating stations went up in Waren,Prenzlau and Brandenburg. In Bavaria, thefirst thermal heating stations have beenconstructed in Straubing, Erding andSimbach-Braunau. The Straubing project, forinstance, provides 21,600MWh of heat eachyear, equivalent to the heating demand insome 4000 low-energy homes each with100m2 of floor space.21 In a project inDortmund, an office complex with morethan 6000m2 of floor space gets its heatingand cooling energy from geothermal energy– the Technorama.22

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Figure 7.6 Geothermal heat: How a hydro geothermal heat plant works

Source: triolog

Residential complex

Heat pump Heat exchanger

Greenhouses

Underground

Injectionborehole

Aquifer

Extractionborehole


7.7 Hot dry rock – power fromunderground

Germany has a number of projects for geot-hermal power production. Such projects arepromising wherever hot thermal water canbe obtained from underground (see 7.6).23

For example, in Neustadt-Glewe a projectthat draws water from 2200m undergroundhas been in operation since 2003. Theturbine used there generates 1.2 million kilo-watt-hours each year.24

In lieu of hot water, hot dry rock can also beused to generate environmentally friendlypower. The process involves boreholes some5–7km deep, but not far apart. The firstborehole is used to inject water under-ground. Fissures in the rock allow the waterto flow towards the second borehole, whereit is drawn back up to the surface. When itpasses through the rock, it heats up so muchthat it creates steam, which can be used todrive a turbine that generates electricity. Butfirst, the water has to be filtered to removeresidual pieces of rock. Once the water hascooled down, it is pumped back under-ground into the injection borehole.

Hot dry rock (HDR) is possible if two thingshold true. First, sufficiently hot layers of rockshould not be too deep if the project is to beeconomically feasible. In Germany, this is thecase especially in the upper Rhine Grabenand in Upper Swabia. Second, the rocksmust allow fissures to be created and keptopen between the two boreholes.Essentially, the fissures constitute a geother-mal heat exchanger. To create one, water isinjected into the boreholes at high pressure.If the geological conditions are right, natu-rally present fissures are expanded to form asort of connecting network. This network iscrucial if the fissures are to stay open.

The HDR method allows geothermal heat tobe used to generate electricity even in coun-tries without hot underground aquifers.Since 1987, a research project in Soultz-sous-Forêts, France has been conducted onHDR. After many years of preparatory work,a 5000m deep, 1.5MW HDR system – thenthe deepest in the world – went into opera-tion in the summer of 2008. A secondborehole will expand the geothermal heatexchanger, bringing total output up to3MW.25

Another project, however, shows the diffi-culty. In Bad Urach, a project with a hot rockof 170°C, 4.5km deep was to provide 3MWof power and 20MW of heat.26 But the diffi-culties encountered during drilling were sogreat that the project has been discontin-ued.

Other geothermal power projects areplanned along the upper Rhine, wheregeological conditions are excellent.27 In mostof these cases, however, hot thermal wateris available. Because deep boreholes costmillions of euros, and there is no certaintythat sufficient hot water will be found, theupfront risk is great in such projects.

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Figure 7.7 Power from hard rock: How the hot-dry-rock method works

Source: Markus O. Häring, Geothermal Explorer Ltd

Waterreservoir

Monitoringborehole

Reservoirmonitoring

Injectionborehole Production

borehole

Heatexchanger

Cooling

Turbine

station

Promote heat

Monitoringborehole

Stimulatedsystem offissures

500–1,000 m

500–1,000 m

4,000–6,000 m

Sed

imen

t

Cry

stal

line


7.8 Other possible sources ofrenewable energy

In previous chapters, we have presentedtypes of renewable energy that have alreadyproven useful in practice or are at leastgenerally considered to be feasible goingforward. Now, we will discuss a few types ofrenewable energy that are still in the testphase. This discussion cannot be exhaustive;rather, it is intended to show that new devel-opments are possible with renewables.

For some time, people have been lookinginto ways to use the enormous power of thesea. From 1960 to 1967, a tidal power plantwith a capacity of 240MW was built at themouth of the Rance River near Saint-Malo,France. It takes advantage of the extremetides using a dam and classic turbines.Unfortunately, there are only a few suchlocations worldwide that are suitable forsuch power plants.

British engineers in Devon, England, havecome up with a new kind of tidal powerplant. Essentially, they put a kind of windmillon the seafloor. Called Seaflow, the planthas already been tested at an output of300kW.28 Ocean waves also contain a lot ofenergy. The most promising approach toexporting this source of energy at themoment is the Pelamis project. Here, threeinterlinking steel tubes float on the waterlike a snake. The waves make the tubesbend against each other, and the motiondrives hydraulics within the tubes, wherepower is generated. Some 750kW systemshave already been sold and some new proj-ects developed.29

Ocean energy has two clear advantages overwind power. First, the tides can be predictedand thereby make a more reliable contribu-tion to our power supply. Second, flowingwater contains far more energy than wind,which means that relatively small systemscan produce relatively large amounts ofenergy. But there is a drawback to all of this:the great forces to be harnessed can also bedestructive. If we are to use ocean energy ona large scale, we will therefore have to comeup with a satisfactory return on our invest-ment.

Solar chimneys are a very different project.Under a giant pane of glass, the sun heatsup air, which rises very quickly up a tower inthe middle. Turbines inside the tower thengenerate electricity. A pilot project with a194m tall tower and an output of 50kWproved successful in Spain in the 1980s – atleast technically, not economically.

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Figure 7.8 (2) New power plant technologies: Seaflow

Source: ISET Kassel

Figure 7.8 (1) New power plant technologies: Solar chimneys

Source: Schlaich, Bergermann and Partner


8.1 Heat pumps

Heat pumps take heat out of the earth,ground water or air and use them forheating purposes. They are therefore sold asenvironmentally friendly heating systems,especially by power providers. But is thistrue?

How they workHeat pumps basically work like reverserefrigerators. While refrigerators take heatout of the inside and emit it on the outside(at the back), the pumps used in heatingsystems send the heat-carrying mediumthrough a heat exchanger underground, forinstance, to collect heat at a low tempera-ture (around 10°C). The heat pump thenbrings that temperature up to around 35°Cand sends the heat into a heating system. Sowhile refrigerators create waste heat whilecooling things down, heat pumps use theheat itself.

The heat can be used in various ways. If ageothermal collector is used, long tubes areinstalled some 2m deep in the earth;another possibility is a downhole heatexchanger (see Figure 8.1) extending downsome 100m. But groundwater and ambientair can also be used. Because cold winter airdoes not contain much heat and groundwa-ter is not available everywhere, most heatpumps in private homes use undergroundheat exchangers.1

The energy that a heat pump itselfconsumes increases the greater the temper-ature difference between the input (thetemperature at the heat source, such asunderground) and the output (the tempera-ture that the heat pump provides to the

heating system or hot water tank). Heatpump systems therefore need quite largeheating radiators, such as for heating, sothat they can work at low temperatures.

Ecological paybackTo increase temperatures, heat pumpsrequire drive energy (W) far below theamount of heating energy (Q) provided bythe system. Q/W expresses the relationshipbetween energy output and input. If thatfigure is three, then the heat pump providesthree times as much heating energy as itconsumes itself. While that may seem like agood performance, if the heat pump runs onelectricity, we need to keep in mind that onlya third of the primary energy used to gener-ate electricity actually reaches your wallsocket (see 1.9). In other words, if theenergy payback of a heat pump is aroundthree or four, the heat pump merely makesup for the energy lost in power generation.

If the pumps are to perform better than acondensation boiler, then the electric heatpump would have to have a paybackexceeding four – which almost neverhappens in practice.2 Heating systems with aheat pump therefore generally perform evenworse in terms of carbon emissions than agood gas-fired heating system, though heatpumps may perform better than oil heaters.3

Heat pumps thus require ideal conditions toproduce acceptable emission values – forinstance, buildings with very low energyconsumption, large-surface heating radia-tors, and a heat source with constantly hightemperatures.

8

8 New Energy Technologies


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New Energy Technologies

8

Figure 8.1 Heat pumps

Source: Energueagentur NRW

Electric heat pump with downhole exchanger: does not offset more carbonemissions than a natural gas heater.


8.2 Solar hydrogen

Hydrogen is not a primary source of energythat could round off the spectrum of renew-ables; rather, it is a secondary energy carrierthat first has to be created from anothersource of energy. If electricity is used to splitwater into hydrogen and oxygen by meansof electrolysis, more energy has to be usedthan can be gained when hydrogen iscombusted.4

Hydrogen can be stored and transportedover large distances if necessary. It can alsoprovide energy in numerous ways. In fuelcells, power and heat can be provided veryefficiently; (catalytic) combustion5 providesdirect heat; and in particular, hydrogen is aprimary candidate for environmentallyfriendly fuels for vehicles. Two advantagesoffered by hydrogen are clear: there is nolack of water; and the only exhaust is water(vapour). There are some technical risks (ofexplosion), but they are not worse than withnatural gas.6 In light of these advantages,scenarios were drawn up for a solar hydro-gen economy in the 1980s (see Figure 8.2).Gigantic solar farms (PV or solar thermal)would produce power in sunny regions tocreate hydrogen by means of electrolysis.The hydrogen would then be shipped else-where to provide an environmentally friendlysubstitute for fossil energy. Back then,‘green hydrogen’ was touted as the ‘energyof the future’.7

Some two decades later, hydrogen remainsthe energy of the future. Some 35 per cent(transport via pipeline) to 50 per cent (liquidhydrogen by ship) of the energy would belost if solar power is converted into hydro-gen and transported from northern Africa tonorthern Europe. The price of solar powerwould effectively rise by a factor of two orthree in the process. The chance that solar

hydrogen will move out of niche marketsand become the dominant energy carriertherefore remains very low.

Hydrogen is not needed to transport solar,wind or hydropower across large distances;modern high-voltage lines are less expen-sive.

This decade, there will also be no need touse hydrogen to store excess solar or windpower to bridge periods of low production.Despite the fast growth of the solar sector,there are only a few hours in a year withaccessible solar and wind power. In the longterm, it might be better to tailor powerdemand to power production (by offeringrates that fluctuate according to supply anddemand, a process known as demandmanagement8) in order to reduce theamount of power that needs to be stored inthe first place.

Overall, Nitsch et al estimate that there willbe no need for hydrogen to store energybefore 2020, if we pursue proper climatepolicy. If we have consistently pursued apath towards a solar economy, we may haveto store some electricity by 2050, with esti-mates ranging from 5 per cent to 38 percent of overall final energy depending onthe specific assumptions.9

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Figure 8.2 Solar hydrogen

Source: Weber, R. Wasserstoff – Wie aus Ideen Chancen warden, IZE Reportagen, 1988

Solar energy

Solar cells

Electricity Hydrogen Applications

Electrolysis

Inverter

Transformer

direct use ofhydrogen

O2 H2

H2O

Hydrogentank

Fuel cell

Electricity

Power generator

Electricity

Heating boiler

Heat

Gas engineMotivepower

For the time being, there is little need for hydrogen to store excess electricity.


8.3 How fuel cells work

Fuel cells have been hot topics in discussionsabout renewable energy. But fuel cells arenot a source of renewable energy them-selves; rather, they are an efficient way ofgenerating electricity (and heat) with lowemissions. The wide variety of different fuelcells makes them especially interesting forsolar energy concepts.

All of the different types of fuel cells10 haveone thing in common: they generate elec-tricity from hydrogen and oxygen. Theoxidizing flame that most people are familiarwith from chemistry lessons basically occursunder controlled conditions in fuel cells.Hydrogen (or a gas such as natural gas andmethanol that contains hydrogen) is inputon one side; oxygen (or ambient air), on theother. At the anode, the catalyst splits hydro-gen into protons, which pass through theelectrolyte, a special membrane that only theprotons can penetrate. The electrons flowout of the fuel cell to the electric appliancebefore passing to the cathode, where theyrecombine with the protons and oxygen toform water.

In this way, the fuel cell directly generateselectric current and heat along with water asa waste product. An indirect process is usedin current central power plants (combus-tion/steam/turbine/generator). Fuel cells aretherefore best thought of as a kind ofbattery that is constantly being ‘recharged’with water and oxygen. Because a singlefuel cell only has a voltage of around 0.7volts, multiple cells are stacked together inpractice.

Fuel cells offer a number of crucial benefits:

• Their electric efficiency is very high, espe-cially under partial load.

• They are extremely clean. If hydrogen isused, the only byproduct is pure water,but even if hydrocarbons are used, nopollutants (such as sulfur dioxide) areemitted.

• They do not have any moving parts andare therefore quiet.

• Different types of fuel cells allow differ-ent fuels to be used – from purehydrogen to natural gas, methanol,biogas and testified coal.

• Their modular design allows them to bebuilt according to specific power require-ments.

Nonetheless, even in 2010, fuel cells stillsuffer from some technical problems andhigh costs; they are still being furtherresearched and undergoing field tests. Serialproduction continues to be postponed, sothis technology should not be expected toplay an important role any time soon.

Fuel cells can be used in many ways.Stationary applications (cogeneration units),mobile applications in the transport sector(‘hydrogen cars’), and small fuel cells forportable appliances (notebook powersupplies, etc.) are some of the mostcommon examples. The first products forsuch applications are already on sale.11

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Figure 8.3 How fuel cells work

Source: The authors

Hydrogen

Oxygen

An

od

e(p

osi

tive

)

Mem

bra

ne

(ele

ctro

lyte

)

Cat

ho

de

(neg

ativ

e)

Water vapour

H2O

H2

1–2 O2

Electron

Proton


8.4 Stationary fuel cells

Fuel cells can be used as a special kind ofcogeneration unit (see 1.9) to provide heatand power to individual homes, but they canalso be used as cogeneration units in indus-try or on the public grid. Below, we discussthe example of fuel cells in individual homesand neighbourhoods.

The prospects initially look good: fuel cellscan be used to replace classic heatingsystems. The house is then heated withwaste heat, and the fuel cell also suppliesthe house with efficiently generated electric-ity, with excess power being sold to the grid.

A number of heating firms and utilitycompanies12 are therefore working inten-sively on this technology. Prototypes arecurrently being tested in practice, but it isnot clear when they will hit the market.13 Inaddition to issues of cost, a number of prob-lems have to be solved first – such as servicelife, fuel type and supply structure – beforefuel cells can become common.

Service lifeCurrently, fuel cells have service lives ofaround 5000 operating hours; the goal is toreach 40,000 hours, equivalent to five yearsof constant operation. Technically, thisincrease could come from strongermembranes and thicker catalyst coatings,but the latter would raise costs because plat-inum is expensive.

The right fuel cell and fuel supplyDepending on the fuel used, a number ofproblems remain to be solved. Hydrogen iscertainly the fuel of choice from the ecolog-ical point of view. Furthermore, it can beused directly in fuel cells. Unfortunately,there is no supply structure for hydrogenyet,14 and the costs of such an infrastructurewould be high. Methanol is toxic, whichlimits the range of possible applications.Furthermore, model calculations haveshown that methanol fuel cells do notreduce carbon emissions in a holistic view.15

The question is therefore why large powerproviders have spent so much time promot-ing fuel cells even as they combat acomparable technology that has beenmarket-ready for years – cogeneration units– with predatory pricing and lobbying. If youare able to make such an investment, wewould recommend that you not wait for fuelcells, but go ahead and purchase a cogener-ation unit today.

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Figure 8.4 The efficiency of fuel cells for domestic power

Source: Authors’ depiction based on Deutscher Bundestag, 14/5054, p86

Natural gas100%

Fuel cell system withnatural gas reformer and

peak load boiler

Losses 20%Electricityca. 33%

Heatca. 47%

The efficiency of fuel cell systems is roughly the same as the efficiency ofcogeneration units


8.5 Fuel cells in mobileapplications

‘The only thing that comes out of theexhaust is water vapour!’ In light of climatechange and smog, such statements seemattractive at first. No wonder most major carmanufacturers have been working on fuelcell cars at some point or another;16 thesecars would have electric drive trains poweredby electricity from fuel cells. A number ofdifferent concepts have been investigated:fuel cells with hydrogen, methanol andnatural gas.

In the mid-1990s, the first prototypes werepresented. Daimler-Chrysler also launched atest fleet of 30 buses and 60 cars in2002/2003.17 Volkswagen has discontinuedits research on hydrogen drive systems andBMW discontinued its field tests on hydro-gen as a fuel for cars with conventionalengines in 2009 .18

Today, no market launch is in sight.19 Onereason is the high cost; fuel cells for cars stillcost around 100 times as much as an inter-nal combustion engine. In addition, there isno hydrogen infrastructure, and the cost hasbeen estimated at €80 billion for a networkof 2000 hydrogen filling stations – and thatwould only cover densely populated areas inGermany. In light of such figures, fuel cellhype has died down considerably.20

Not even the environmental benefits areconvincing if we look at them closely. Whilefuel cell cars are very efficient, especially inpartial load, a lot of energy is needed toprovide the fuel. When we compare fuel cellcars running on various types of fuel toconventional cars in terms of environmentalimpact, the benefits are slight, and technicalprogress with conventional cars is alsoexpected in the years to come.21

One crucial aspect is often overlooked whenassessing hydrogen-powered fuel cells. Ifrenewable electricity is used to generatehydrogen for a fuel cell in a car, the carmakes do with less conventional fuel,leading to 190g fewer emissions of climategases per kilowatt-hour.22 But because thatkilowatt-hour was not sold to the grid, otherpower plants will have to generate it,increasing emissions by 590g (see Figure8.5). In a holistic view, the use of ‘greenhydrogen’ does not actually reduce emis-sions in our current power supply system,but rather increases emissions of climategases.23

If at all, hydrogen produced from renewablepower for fuel cell cars is a very long-termoption for the Solar Age. The highly detailedpublications about research into and tests ofemission-free fuel cell cars24 therefore shouldnot mislead us into believing that the acuteproblems in our transport system can besolved this way. Car travel needs to beavoided more often, conventional cars needto become more efficient and emit lesspollution, public transport needs to be usedmore often, and speed limits need to bereduced.

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Figure 8.5 Mobile applications: Will hydrogen fuel cells help the climate?

Source: Authors’ depiction based on Wuppertal Institut für Klima, Umwelt, Energie GmbH

CO2 equivalents/kWh600g

400g

200g

0g

–200gGreateremissions fromthe additionalpowergenerated infossil fuel plants

Lower emissionsin transportwhen hydrogenfuel cells replacegasolineengines

Greater netemissions fromthe use of solarhydrogen infuel cells

Even if renewable electricity is used to produce hydrogen for use infuel cells in cars, the carbon impact is negative.

590g

400g

190g


9.1 The potential in Germany

The previous chapters discussed varioussources of solar energy and the componentswithin a solar energy supply. In this chapter,we provide a more holistic overview – whatshare of our energy supply can the varioussources of renewable energy have, and howmuch energy can they provide?

The supply of solar energy is gigantic (see1.6). However, the theoretical potential cannever be completely exploited because avail-ability depends on time and location, theefficiency of the technologies used and otheraspects. After these limitations have beentaken into account, the technical potential ismuch lower than the theoretical even beforewe have discussed economic feasibility.

A number of studies have been produced onthe technical potential of renewables inGermany, with varying results. In 2004, acomprehensive study conducted by a numberof renowned research institutes came to thefollowing conclusions1 (all figures per year;potential under greater nature conservationrequirements in parentheses):

Power generation (in TWh)Hydropower 25 (24)Onshore wind 65 (45–55)Offshore wind 110 (110)Photovoltaics 105 (105)Biomass 85 (70)Geothermal2 66–290 (66–290)

Heat (in PJ)Biomass 525 (425)Solar thermal 1040 (1040)Geothermal 1175 (1175)

Fuels (in PJ)Biomass 490 (320)

This potential is currently only used to alimited extent. Of the 25TWh of hydropowerpotential, 21 have already been exploited,but the only other forms of energy utilizedto a great extent are biomass for heat(around 300 of 525PJ) and more recentlyonshore wind power (40 of 65TWh).3

The total potential of renewable power is350–719TWh, roughly equivalent to 62–127per cent of current German powerconsumption (2003: 585TWh). In otherwords, a renewable supply of power ishardly a utopia; the potential is there – wesimply need to use it.

Depending on the type of biomass used, therenewable potential for heat lies between42 per cent and around 60 per cent of thefuel consumption level of 2003 (roughly5300PJ). If the tremendous conservationpotential in space heating is exploited, thatshare would increase.

In terms of current consumption, the poten-tial for fuels is the lowest. But even if allbiomass is dedicated to fuel production, wewould only be able to cover a third of ourcurrent consumption in the best case. Whilewe can import biofuels, we will not be ableto achieve a renewable fuel supply unless weaccept less mobility and greater vehicle effi-ciency (see 5.10).

Overall, a holistic view reveals that a solarstrategy can only be successful if we greatlyincrease energy efficiency and conservation(see 1.8).

9

9 Current Use and Potential


141

Current Use and Potential

9

Figure 9.1 Technical potential of renewables in Germany and ecologically optimizedscenario

Source: DLR, ifeu, Wuppertal Institute, 2004

Power generation (in TWh/a)

Heat generation (in TWh/a) Fuels (in TWh/a)

350

300

250

200

150

100

50

0

350

300

250

200

150

100

50

0

Geo

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Biom

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Win

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wer

Off

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Onshore

Sola

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erm

al

Phot

ovol

taic

s

Biom

ass

Hyd

ropo

wer

Biom

ass

Geo

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9.2 The future has alreadybegun in Germany

Since the beginning of the 1990s, produc-tion of renewable energy has grownconsiderably in Germany. Wind power is themost impressive example. By 2005, 14 yearsafter the first feed-in tariffs were offered,wind power had increased 100-fold since1992. Photovoltaics is also booming. From1990 to 2005, the amount of solar powergenerated in Germany increased by a factorof 1000.4 But other types of renewableenergy have also grown at rates that wouldmake other industries envious (see Figure9.2).

This boom was the result of specific policies:

• The Power Feed-in Act of 1991 and itssuccessor, the Renewable Energy Act(EEG, see 11.9) ensure that producers ofrenewable power get a return on theirinvestment in renewable power genera-tion.

• The 100,000 Roofs Programme providedcrucial upfront financing for photo-voltaics from 1999 to 2003. Germanynow has companies all over the countrywith the expertise to install solar powerarrays. In addition, the cost of the manu-facture of PV arrays has droppedconsiderably, thereby paving the way forfurther growth.

• Part of the proceeds from the EcologicalTaxation Reform were devoted to theGerman government’s Market IncentiveProgramme, which had an annualbudget of around €200 million (2005). Inaddition to solar thermal systems, energyfrom biomass was also supported.

• A growing number of tradespeople arediscovering solar as a business field andworking to convince their customers topurchase solar equipment. To supportthem in this endeavour, Germany imple-mented such national campaigns as‘solar power – now’s the hour’, ‘solarheat plus’5 and ‘heat from the sun’, aninformation campaign across Germanyabout solar thermal.

For a number of reasons, the renewableenergy sector will continue to grow quicklyin the next few years:

• New production plants for solar cells andsolar panels have increased supply.Production capacity for solar powertechnology has grown more than tenfoldsince 1999.6

• In June 2009, the EU’s RenewablesDirective took effect with the goal ofcovering 20 per cent of final energyconsumption by 2020 from renewables.

• At the level of the EU, all utility compa-nies are obligated to show consumershow their power is generated.7 As aresult, the debate about where powercomes from has been revived. A numberof households and businesses thereforedecide to purchase clean power, whichwould help increase renewable powerproduction (see 12.2).

• Solar thermal systems are now of veryhigh quality according to Germanconsumer protectionists.8

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Figure 9.2 Germany, the transition has begun: Power and heat from renewables

Source: BMU, Erneuerbare Energien in Zahlen, 2009

Power generation in 1995, 2008 and 2009 (in TWh/a)

40

35

30

25

20

15

10

5

0Hydropower Wind power Biomass Photovoltaics

20.7 20.4

1995

2008

2009

Heat generation in 1997, 2008 and 2009 (in TWh/a)

105

100

90

80

70

60

50

40

30

20

10

0Biomass Solar thermal Geothermal

1997

2008

2009

19.0

97.5

105.2

0.74.1 4.7

1.64.6 5.0

1.5

40.6 38.6

0.7

22.824.5

0.01

4.46.6

48.5


9.3 EU votes for renewables

In its White Paper for Strategy and ActionPlan for renewables,9 the EuropeanCommission stated in 2001 that renewableshave not been sufficiently used in the EU; ittherefore calls for urgent action in policiesfor the European Union.

The Commission believes there are severalreasons why a comprehensive strategy topromote renewables can no longer be donewithout:

• Currently, the EU imports 50 per cent ofits energy. If nothing is done, theCommission estimates that this sharewill rise to 70 per cent by 2020.

• If the EU does not manage to increasethe share of renewable energy consider-ably (from the current level of 6 per centto more than 12 per cent), the EU willhave a hard time fulfilling its environ-mental protection obligations incompliance with both European andinternational agreements.

• The Commission holds that renewableenergy is an important future market.Since other countries, such as the US andJapan, are currently implementing meas-ures to support their domesticrenewables industries, the EU believesthere is a great danger that Europeanindustry might lose its leadership posi-tion in this sector. ‘Unless we have aclear, comprehensive strategy followedup by legislation, there will be delays inthe growth of renewables.’10 TheCommission also feels that a ‘long-term,reliable framework for the growth ofrenewables’ is an important requirementfor companies to make investments.

Against this background, the EU adopted agoal in 2001 of increasing the share ofrenewables in total energy consumption to12 per cent by 2010. As the White Paper putit:

Considering all the important benefits ofrenewables on employment, fuel importreduction and increased security ofsupply, export, local and regional devel-opment, etc. as well as the majorenvironmental benefits, it can beconcluded that the Community Strategyand Action Plan for renewable energysources as they are presented in thisWhite Paper are of major importance forthe Union as we enter the 21st century.11

In the autumn of 2001, the EU thereforeadopted its Directive on the Promotion ofElectricity from Renewable Energy Sources,which states that the share of renewableelectricity within the EU is to increase from13.9 per cent in 1997 to 22 per cent in2010.12 By 2007, renewable power genera-tion within the EU-15 had increased to 16.6per cent.

In 2009, the EU adopted more ambitiousgoals. The share of renewables in totalenergy consumption is to increase to 20 percent by 2020. Furthermore, biofuels are tocover at least 10 per cent of total gasolineand diesel consumption.13

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Figure 9.3 The EU’s dependence on energy imports is growing

Source: Kommission der Europäischen Gemeinschaften, Grünbuch, 2001

Under the status quo . . .

50 per centenergy imports

70 per centenergy imports

50 per centdomestic supply

EU 1999 EU 2020

... the EU’s dependence on energy imports will grow.

30 per centdomestic supply


9.4 Expanding renewables inthe EU

A look at the various EU member statesreveals considerable differences in the use ofrenewables, mainly as the result of differentgeography. For example, countries with tallmountains have much more hydropowerpotential than flat countries. It thereforecomes as no surprise that Austria (65 percent) and Sweden (44 per cent) get a lot oftheir electricity from hydropower, whilehydropower is negligible in The Netherlandsand Denmark, which each have only 0.1 percent hydropower.14

But the differences in the potential ofrenewable energy cannot simply beexplained by the differences from oneEuropean country to the other. For instance,France, the UK and Ireland have the bestconditions for wind power. A wind turbine inIreland can produce twice as much electric-ity as one in an average location in Germany.Nonetheless, Germany produced four timesas much wind power as Ireland and the UKtogether in 2008, and installed wind capac-ity was about five times greater.15

Unsurprisingly, solar thermal is used insouthern Europe more often than in north-ern European countries like Sweden. Forinstance, Greece made up about 14 per centof the collector area installed in EU in 2008.It thereby only came in third, however,behind Germany, which made up about 40per cent of the collector area installed inEurope with 11.3 million square metres. Interms of per capita installed collector area,Austria came in first with a bit more collec-tor area than Greece. In contrast, sunnycountries such as Italy and Spain do not evenhave 5 per cent of the solar thermalmarket.16

Within the EU, photovoltaics has boomed inthe past few years. In 2004, roughly 1GWwas installed, but that figure had grown by2008 to 9.47GW. More than 90 per cent ofthe systems are in Germany (56 per cent)and Spain (36 per cent), both of which havefeed-in tariffs. In contrast, sunny Portugaland Greece only made up 0.7 and 0.2 percent of the European market, respectively.

Overall, renewables covered some 9 per centof final energy consumption within the EU in2006. Just over half of that was biomass,primarily wood and waste wood. In Finland,Sweden and Latvia, biomass makes up alarge part of the national primary energy pie.But in terms of absolute volume, biomass isthe largest in Germany (151TWh) andFrance (135TWh) in 2007.17

In addition to natural conditions, policies inthe member states determine how muchrenewable energy is produced. Anotherfactor is domestic fossil energy resources,decisions for or against nuclear power, andgeneral attitudes about energy.18

In 2004, the European Commissionreviewed renewables targets for 2010.Denmark, Germany, Finland and Spain werefound to be on the right path.19 In 2007,Germany and Denmark had already reachedtheir targets for 2010 for renewable electric-ity, while France and Italy had not increasedtheir share of renewable electricity at allfrom 1997 to 2007 (See Figure 9.4).

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Figure 9.4 Expanding renewables in Europe: Power generation in EU-15

Source: BMU: Erneuerbare Energien in Zahlen, 2009

Renewable electricity as a percentage

Belgium

Denmark

Germany

Finland

France

Greece

UK

Ireland

Italy

Luxembourg

Netherlands

Austria

Portugal

Sweden

Spain

0 20 40 60 80 %

Target value for 2010

Renewable electricity in 1997

Renewable electricity in 2007


9.5 Renewables worldwide

Renewable energy currently covers some 17per cent of global primary energy demand.Traditional biomass (firewood for cookingand eating) makes up the largest piece ofthat pie; unfortunately, such practices causeirreversible damage to forests, and thesmoke from open fires is a health risk.20

Researchers and industry are therefore nowworking on second-generation biomass,which is both sustainable and environmen-tally friendly.

Water power makes up the second biggestblock of renewable energy. Worldwide, itprovides 90 per cent of renewable electricity.Wind and solar power are small by compari-son, though they are growing quickly. From2000–2008, grid-connected solar arraysgrew globally by 60 per cent per year,compared to 20–30 per cent per annum forwind turbines. Policies in Japan, Germanyand Spain produced strong growth for grid-connected photovoltaic arrays. These threecountries alone made up around 80 per centof the 13GW of grid-connected solar capac-ity installed by 2008. But photovoltaics is alsoused outside of the Organisation forEconomic Co-operation and Developmentcountries. In regions without grid access,millions of Solar Home Systems (see 3.3)provide electricity for domestic consumption.Many countries (India, China, Egypt, Brazil,Peru, etc.) have comprehensive support poli-cies. In Bangladesh alone, a project will install1.3 million Solar Home Systems. There hasalso been tremendous progress in the plan-ning and construction of solar thermal powerplants over the past few years. In 2008, 8GWwas either in planning or under construction,6GW of which was in the US alone.21

Micro-hydropower, wind power andbiomass cover roughly the same amount of

power production. China comes in first withmicro-hydropower; indeed, the Chinesehave more than half of global installedcapacity, often to supply power to a villagewithout grid access.

In 2008, the US, Germany and Spain had thegreatest installed wind capacity, but coun-tries such as India, Italy and China have alsonow discovered this source of environmen-tally friendly power (see Figure 9.5).

China is also the leader in solar thermalenergy. Simple systems are manufacturedlocally at low prices, making them affordablealready without any further subsidies. Notsurprisingly, China has more than 65 percent of global installed capacity.22 Israel alsouses solar thermal arrays to a large extent;indeed, it is the only country in the worldwhere solar hot water systems are requiredfor all new buildings.23

Worldwide, some 79 billion litres of biofuelswere produced in 2008, equivalent toaround 3 per cent of global fuel consump-tion. The leading ethanol producers areBrazil and the US (see 5.9), with Germanyand the US being the leader for biodiesel(around 12 billion litres worldwide).

Efforts are being made around the world toexpand renewable energy. In 2008, someUS$120 billion was invested in this field, andthat figure does not include largehydropower, which entailed a furtherUS$40–45 billion. Far more was nonethelessinvested in conventional energy: someUS$150 billion (in 2004). Worldwide, some2.4 million jobs had been created in therenewable energy sector by 2006, but thisfigure has increased dramatically sincethough reliable global figures are not yetavailable.24

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Figure 9.5 Renewables worldwide

Source: REN21: Renewables Global Status Report 2009

Renewable electricity (in a select number of countries, excluding hydropower)

Inst

alle

d c

apac

ity

in g

igaw

atts Photovoltaics, grid-connected

Geothermal

Biomass

Wind power

Micro hydropower

Share of solar hot water/heating capacity existing, top 10 countries, 2007

European Union 12.3%

Turkey 5.8%

Japan 4.1%

Israel 2.8%

Brazil 2.0%

United States 1.3%

Australia 1.0%

India 1.2%

Jordan 0.5%

Other 2.4%

China 66.6%

Worldtotal

Devel-oping

countries

EU-27 China UnitedStates

Germany Spain India Japan

30028026024022020018016014012010080604020

0


9.6 A long-term solar scenariofor Germany

In the Introduction (1.7), we mentioned anearly scenario for the transition to the SolarAge –the Institute for Applied Ecology’sEnergy Transition study from 1980. Today,three decades later, the strengths and weak-nesses of various sources of renewableenergy – and especially their potential – areeasier to describe. We also now have morecomprehensive studies providing scenariosfor a sustainable solar energy economy.

In 1998, the Wuppertal Institute published aconcept for a solar supply of energy forEurope.25 They found that there are no prin-cipal technical or financial hurdles tocovering more than 90 per cent of ourenergy demand with renewable resources by2050. In fact, we could even get all of ourenergy from renewables.

The German Aerospace Centre and theFraunhöfer Institute for Solar Energy Systemsalso published a long-term solar scenario forGermany in 1997.26 It was updated in 2004to take better account of ecologicalaspects.27 By 2050, the following targetsshould be reached:

• Total energy demand is to drop by some51 per cent through the incrementalimplementation of efficient technology.28

• Renewables are to be expanded signifi-cantly to cover nearly 45 per cent ofdemand by 2050.

• Nuclear power is to be phased outbefore 2030 and fossil energy will mainlybe consumed in cogeneration units.

Different sources of renewable energy willexpand at different rates.

By 2020, wind energy and biomass willmake up the largest share of the renewablepie. Solar thermal collectors, photovoltaicsand geothermal will not make up significantpieces of the pie until then despite fastgrowth rates (see Figure 9.6). Fuel frombiomass will grow prudently becausestationary consumption of biomass willremain less expensive and reduce carbonemissions more in the beginning.

From 2020 to 2050, the share of renewablesdoubles in this scenario, with solar thermal,photovoltaics and imports of solar power(either from photovoltaics or concentratedsolar power) posting the greatest growth. By2050, carbon emissions will have beenreduced by 80 per cent compared to thelevel of 1990. By then, the potential ofhydropower, biomass and wind poweronshore will have largely been exhausted,but the potential of other sources of renew-able energy will still offer considerablegrowth potential.

Of course, any scenario with a horizon of 40years must be taken with a pinch of salt.Nonetheless, such scenarios show the possi-bilities, costs and time frames in which thepotential of individual sources of renewableenergy can likely be tapped.

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Figure 9.6 A long-term scenario for Germany: Renewables as a part of primary energyconsumption

Source: DLR, ifeu, Wuppertal Institute, 2004

Nature Conservation Plus II scenario

Primary energy (PJ/a)

4,000

3,500

3,000

2,500

2,000

1,500

1,000

500

0

Import of renewablesGeothermalSolar collectorsBiomass

PhotovoltaicsWindHydropower

2000 2010 2020 2030 2040 2050


9.7 The 100 per cent target

As previous sections have demonstrated, wecan get all of the energy we need fromrenewables. Nonetheless, it will still takeseveral decades for this target to be reachedin many areas. It is therefore crucial forfurther progress towards the Solar Age thatwe not lose sight of the target: completelyphasing out nuclear and fossil energy. Oneimportant first step is for individual commu-nities, regions and countries to attain a 100per cent renewable energy supply – or worktowards one for the foreseeable future.29 Wealready have some encouraging examples.

The bioenergy village of Jühnde –100 per cent biomassThe village of Jühnde near Göttingen,Germany, has been providing its 850 inhabi-tants with power and heat using almostexclusively renewable energy since 2005. Acommunity-owned biogas unit (700kW) anda woodchip-fired heating plant (550kW)provide the energy. Heat is distributedthrough a network of pipes with a totallength of 5.5km. These units are fired exclu-sively with local resources, which boosts thelocal economy. Biogas comes from 800 cowsand 1400 pigs on nearby farms, while grass,garden waste and dedicated energy crops(rapeseed, corn and sunflowers) are alsoused. The village’s cogeneration unit gener-ates some 4 million kilowatt-hours of powereach year.

Güssing – renewables provideeconomic growthGüssing is a town in eastern Austria. Localcompanies were taking advantage of theclose border to Hungary, with the result thatlocal jobs were being lost. In 1988, theBurgenland region had become the poorestregion of Austria. In 1990, the communitycouncil of Güssing therefore resolved to getall of its energy from renewables.

Over the years, buildings have been reno-vated to reduce energy consumption, abiodiesel unit was installed, two districtheating networks have been set up, andAustria’s largest wood-fired biomass unitwent into operation. Because the town hadpiped heat to spare, it attracted 50 newbusinesses, which created more than 1000new local jobs.30

In the past few years, some 90 communitiesand regions in Germany have set a goal of100 per cent renewables. They are workingto improve regional added value, increaseenergy security and protect the climate. Aresearch project at the University of Kassel isstudying which factors helped Germany getto 10 per cent and how that knowledge canbe shared to bring the country to 100 percent.31

Iceland already gets around 75 per cent ofits primary energy consumption from renew-ables. The island has more hydropower andgeothermal energy than it can use.

To reach the 100 per cent target, the trans-port sector will have to be restructured.Hydrogen will have to be made from renew-able electricity as a fuel for vehicles. The firstpilot projects with cars and buses32 and aship33 have already started. Unfortunately,the economic crisis that started in 2008 hasslowed down progress.

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Figure 9.7 Bioenergy village of Jühnde: 100 per cent biomass

Source: Authors’ depiction based on IZNE, Bioenergiedörfer, Göttingen, 2006

Biogas unit

Cogeneration unit

Peak load boiler(heating oil or

rapeseed diesel)

BiogasHeat

Green electricity

Electricity

The village of Jühnde

Heat

Woodchip-firedheating plant


10.1 What do we do when thesun isn’t shining?

Sceptics often point out that renewable elec-tricity is intermittent. The question then ishow industry is to manufacture when thesun is not shining. This problem must betaken seriously. Power production andconsumption always have to match on apower grid. And because wind and photo-voltaics fluctuate daily and hourly, they leaveholes that have to be filled.

But first we have to point out that a countrythe size of Germany is almost nevercompletely covered with clouds and withoutwind at the same time. By spreading powergeneration systems over a large area(Germany/the EU) and by using differenttypes of renewable energy, the problem ofintermittency is reduced.

Furthermore, some types of renewableenergy, such as large run-of-river plants, canbe used basically all the time. And storagedams allow energy to be stored to providefor low production at other times. Biogasunits connected to cogeneration systemscan also help balance power consumptionand production, as can power generatedfrom biomass in the heating plants.

Researchers have also studied this problemintensively. For instance, the GermanAerospace Centre has worked with theFraunhöfer Institute for Solar Energy Systemsto see how power demand can be coveredin a system of mainly renewable energysources.1 The researchers assumed that 25per cent of power would come from cogen-eration in 2050, with 60 per cent comingfrom renewables. They also assume that this

would be the same quality of power that wehave today.

The researchers found that the remainingfossil fuel power plants would be running atfar lower capacity. In the reference year(1994), 55GW of power plant capacity wasin operation more than 4500 hours a year,but that figure would fall to below 15GW by2050. In other words, future power plantswill have to be easy to ramp up and down ifwe are to compensate for fluctuations inrenewable power production, which canonly be controlled to a limited extent. Thebest option here is gas turbines andcombined cycle plants.2

To match power consumption and produc-tion, the researchers also propose moreadvanced methods of demand managementthan are used today.3 Appliances such as airconditioners, refrigerators and water heaterscan be switched off for brief periods tobridge times when renewable powerproduction is dipping.

The authors of the study do not believe thatsignificant amounts of electricity storage(such as in hydrogen) will be needed in theforeseeable future.

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Figure 10.1 What do you do when the sun isn’t shining? Annual solar and wind patterns

Source: Kohler, Leuchtner, Müschen, Sonnenenergiewirtschaft, 1987

Wind Solar

Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec

100%

80%

60%

40%

20%

0%

The fluctuations in the energy supply from solar and wind partiallycompensate for each other


10.2 How can we store largeamounts of electricity?

Up to 2007, it was no major problem for thegrid to absorb wind and solar power, eventhough they are intermittent. But today,there are times when more renewable elec-tricity is generated than is needed, especiallywhen power consumption is low and a lot ofwind power is being generated. As renew-able energy continues to grow, the situationwill become more common.

Furthermore, there will also be times whennot enough renewable electricity is availableto cover demand.

There are various ways to store significantamounts of excess electricity in such situa-tions so that it can be available when powerproduction is lower later.4

Pumped storage plants are a well under-stood technology. They consist of twobasins, one above the other, connected bypipes. Excess electricity is used to pumpwater from the bottom basin into the topone. When demand exceeds production, thewater is then let down into the lower basinagain; on its way, it drives hydropowerturbines. Germany already has more than 30such power plants with an efficiency of upto 85 per cent and an overall capacity of6GW. The potential for these power plantsis, however, already largely exhausted inGermany, though there is potential forexpansion in Switzerland and Scandinavia.

Compressed air energy storage (CAES) is lesswell known. In this technology, excess elec-tricity is used to compress air up to 100 barin subterranean salt caverns. Wind power isneeded, the compressed air essentiallyserves the same function as the compressorstage of the gas turbine, which reduces the

turbine’s natural gas consumption by 40–60per cent (see Figure 10.2).5 The firstcompressed air power plant (in the world)was set up just outside of Bremen, Germany,in 1978.6 It only achieved an efficiency of 42per cent, but modern systems have efficien-cies up to 55 per cent. Researchers are nowworking to store the heat from thecompressed air so they can feed it back to beout flowing air wind power as needed. Ifthey succeed, efficiency is expected to riseup to 70 per cent.

Although there has been a lot of mediacoverage about storing excess electricity inhydrogen, this option is not effective. Ifhydrogen is made from water by means ofelectrolysis and then converted back intoelectricity in a fuel cell, the overall efficiencyis only around 25 per cent (see Chapter 8).7

A number of other approaches still in thetest phase focus on using existing appli-ances/applications to store electricity. Oneexample8 is hybrid cars, which have both aninternal combustion engine and an electricmotor powered by batteries. These cars caneasily be converted into ‘plug-in hybrids’ sothat they can be charged from a wall socket.Excess electricity could then be stored inthousands of car batteries, but the carscould also provide electricity when need be.If a large number of such relatively smallbatteries work together, we end up with away to store a large amount of electricity.For instance, 100,000 plug-in hybrids couldstore or generate around 1000MW of elec-tricity.

Large refrigerated warehouses can also beused to store electricity. When there is excesselectricity, they can cool down a bit more,and when less renewable electricity is avail-able they simply stay off longer.

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Figure 10.2 How much energy can be stored? Energy storage with compressed air systems

Source: Fritz Crotogino, KBB Underground Technologies GmbH, Hannover

CompressorsEngine/generatorGas turbineCavern

Naturalgas

Air

Compressed air energy storage in Huntorf (Northern Germany)


10.3 Can carbon emissions notbe avoided lessexpensively?

Every time fossil energy is burned, carbondioxide (CO2) is emitted. Along with othergreenhouse gases, CO2 causes the green-house effect, which is changing our climateand increasing the average temperature onthe Earth. There are basically four ways toprevent carbon emissions.9

1 Making fuel consumption more efficientand conserving energy.

2 Using fuels with less carbon content(such as natural gas instead of oil and oilor gas instead of coal).

3 Increasing the efficiency of energyconversion (for example, by makingpower plants more efficient and usingcogeneration instead of getting electricityfrom conventional condensation plants).

4 Using more renewable energy.

Each of these actions entails costs, on theone hand, and a number of benefits (in addi-tion to lower carbon emissions) on the other.To correctly determine the carbon avoidancecosts, these costs and benefits have to beweighed off against each other – which isnot easy.

Furthermore, we have to keep in mind whatangle we come at the calculation from. If wehave a macroeconomic view, the results willbe different than those calculated by privateinvestors or utility firms. Furthermore, theexternal costs of our energy supply (see11.3) must be included in the calculation.Although attempts to calculate carbonavoidance costs all have their drawbacks,10

we will take a look at the general ideabelow.

The carbon avoidance costs are much higherfor photovoltaics than for wind energy, solarthermal or energy conservation. In otherwords, the cost of avoiding the emission ofa ton of carbon is several times greater thanfor other technologies at present.

Under German feed-in rates, however, thesituation looks different for an averageGerman homeowner, who also has easyaccess to low-interest loans for PV invest-ments. Carbon avoidance costs are thereforevery low for such investors. But whatever thecase, investors generally do not base theirdecisions on carbon avoidance costs.

The benefit that investors get from photo-voltaic arrays is not limited to the moneythey get in return for their solar power, butalso extends to the feeling of having made auseful investment that is good for the envi-ronment, helps foster a young industry, andprovides a little bit of independence fromutility companies.

Such households may have been able tohave the same positive environmentalimpact with energy-saving technologies at alower cost, but the fact that they chose aphotovoltaic array shows that subjectiveassessments of costs and benefits are notthe same thing as theoretical macroeco-nomic assessments of costs based purely oneconomics.

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Figure 10.3 Can CO2 be offset less expensively in some other way? CO2 avoidance costs (ineuros per ton)

Source: The authors

Insulation in old buildings

Power conservation, such as efficient appliances

Cogeneration

Wind power

Solar thermal

Photovoltaics

Negative carbon avoidance costs

= cost savings from climateprotection

High carbon avoidance costs

= additional costs fromclimate protection

Hydropower

Carbon offsets are not the only issue: despite the high carbon avoidancecosts, solar energy is very popular


10.4 What is the energypayback?

With wind turbines and solar arrays gettingbigger all the time, some wonder whetherall of the materials used (‘grey energy’) areworthwhile – or, put differently, do we investmore energy in such systems than they willbe able to generate?

The term to understand here is ‘energypayback’. It is an indication of how long thesystem needs to produce the energyinvested in it. After that time, it beginsproducing a ‘surplus’. If a system can remainin operation longer than it needs to pay backthe original energy investment, the energypayback is positive.

Energy payback not only depends on manu-facturing, but also on how the system isused. For example, a wind turbine in windylocations will produce more power, therebyforeshortening its energy payback. Pick andWagner11 have calculated the energypayback of a wind turbine under differentwind velocities and different tower heights.They found that it took the turbine between3.3 months on the coast (wind velocities of6.87m per second) and 6.2 months for aturbine inland (65m up, with winds at5.91m per second). The Institute of AppliedEcology came to similar conclusions.12

The energy payback of a solar thermalsystem depends on the material used, theamount of sunshine and the solar coveragerate – but also on the heating system itpartially offsets. If the heating system is oldand inefficient, the collectors will pay forthemselves within less than six months. Butif a condensation boiler is offset, the energysavings are lower and the energy payback islonger. Depending on the material used andthe amount of sunlight, energy paybackgenerally ranges from 0.6–2 years.13

With the crystalline solar cells generally usedtoday in photovoltaic arrays, the energypayback is generally around three to fouryears north of the Alps and two years southof the Alps depending on solar conditionsand what is included in the calculation. Butthese figures are falling all the time, and by2010 systems north of the Alps have proba-bly already reached an energy payback ofonly two years.14

In conclusion, energy payback depends on anumber of factors and is hard to state ingeneral. But all of the available data clearlyshow that systems running on renewableenergy produce several times as muchenergy as was invested in them. Their energypayback is therefore clearly positive.

In contrast, nuclear and coal plants alsorequire a fuel in addition to the materialsand energy for construction. Because theseplants produce less energy (as electricity)than is contained in the fuels consumed, weare always putting more energy into theseplants than we get out of them. Their energypayback is therefore always negative.

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Figure 10.4 Comparison of service life with energy payback

Source: Institut für Elektrische Energietechnik Berlin, 1996, and Photon, Sept 2005

Energy payback is an indication of how long a system needs to generate theenergy needed for its manufacture

Wind power

Photovoltaics

Solar thermal

Energy payback

Service life

0 5 10 15 20 25 30 35

Time in years


10.5 Are renewables job killers?

Studies about how renewables will affectthe job market are controversial for a goodreason. While the number of employees atcompanies manufacturing wind power andsolar equipment – and even at suppliers –can be stated quite exactly, it is much harderto demonstrate downstream effects, whichcertainly occur, but are impossible to empiri-cally demonstrate.15

In a study on how the German job marketwill change when we switch to renewables,the Institute of Applied Ecology not onlyassumed that renewables would offset someof our fossil energy, but also all nuclearpower. This sustainable energy approachwas expected to create some 200,000 jobsover the long term because energy conser-vation technologies and renewable energywould replace energy imports.16

Current events in Denmark confirm thesefindings. There, the number of peoplereceiving unemployment or welfare benefitsfell from 14 per cent to 6 per cent, mainlybecause nearly 65,000 jobs were created inthe renewables sector. In the wind sectoralone up to 1999 more than 20,000 newjobs were created.17 Exports of wind turbineswere one reason.18 Likewise, by the autumnof 2008 some 280,000 jobs had beencreated in Germany in the fields of renew-able energy and energy efficiency.19

The jobs created offer two crucial benefits:

1 To the extent that the jobs created arerelated to a domestic market, they arenot dependent upon globalization.Renewable energy sources and efficientenergy consumption systems are gener-ally produced and used locally. A largepart of the work performed takes placein local trades and engineering firms.

2 The jobs created do not entail anyfollow-up costs (such as road construc-tion); on the contrary, they lower socialcosts by reducing environmental impactsand social conflicts.

Another benefit that is often overlooked hasto do with innovation and growth potentialbrought about by the growth of the domes-tic sales market. The European Commissionhas understood this aspect and thereforeexpects the growth of domestic markets forrenewable energy and a doubling of theshare of renewable energy within the EU toprovide European industry with great oppor-tunities for exports and growth. ‘Annualexports are expected to reach €17 billion peryear by 2010, possibly leading to thecreation of up to 350,000 additional jobs.’20

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Figure 10.5 85,000 wind power jobs (2008)

Source: Eigene Dartstellung nach: VDMW and BWE: Windenergie in Deutschland

Planners, experts

85,000 jobs in the windpower sector in

Germany (2008)

Concrete sector

Steel sector

Transportation,logistics

Manufacture ofsystems andcomponents

Service andmaintenance

Operation

Financial services


10.6 Is the Solar Age the end ofpower monopolies?

In Germany, eight companies dominated thepower market up to 1998, when the marketwas liberalized. That year, RWE,PreussenElektra, VEAG, EnBW, BayernwerkAG, VEW, HEW and BEWAG generated 85per cent of the electricity in Germany. Theymainly had two ways of marginalizing smallcompetitors:

• Predatory pricing kept highly efficient,environmentally friendly cogenerationunits off the market.21

• The Feed-in Act (11.9), which hadlevelled the playing field for wind powerand hydropower, was considered uncon-stitutional, and numerous court caseswere filed.

Liberalization further concentrated power ina smaller sector – VEBA and VIAG(PreussenElektra) merged in 1999 to becomeE.ON; RWE and VEW also merged.22 Overall,only four large conglomerates (RWE, E.ON,EnBW and Vattenfall) currently dominate thepower market in Germany.

In our energy transition, local resourceswould be used and power plant structureswould be distributed. Here, more localresponsibility – and political input – isneeded. To what extent have these require-ments been fulfilled?

Current data allow us to draw some conclu-sions.23 First, the good news: small firms andprivate investors currently make up some 90per cent of all renewable power generatorsin Germany. On the one hand, that figureclearly demonstrates how committed privateinvestors are to paving the way towards theSolar Age; on the other hand, it also showshow reluctant some power providersremain.

A look at the amount of electricity generatedwith renewables shows a clear trend in thepower market. Utility companies – be theylarge conglomerates, regional private firms ormunicipal utilities – used to be the only onesrunning power plants. And because utilitieswere the ones operating large hydropowerdams, these firms also were responsible for alot of the renewable electricity generated. Asrecently as 2000, they still made up 60 per centof the market. But the strong growth in windenergy, biomass and solar power have broughtabout a change; nowadays, private investorshave taken the lead. When it comes to thesethree types of renewable power, more than 70per cent of the power generated is owned byprivate investors (see Figure 10.6).

The share of utilities in renewable powercontinues to drop. By 2005, the figure hadfallen to 35 per cent. At the same time, themarket segment of renewables continues togrow. From 1999–2005, the amount ofrenewable electricity generated more thandoubled, reaching a 10 per cent share ofenergy consumption in 2005.24 But takentogether, these two trends mean that newmarket players are at work on the powermarket, and the influence of monopolies canbe expected to drop somewhat. But as soonas large offshore wind farms start going up,this trend could reverse because only largefirms with deep pockets can finance suchprojects. A change in taxation also meansthat relatively few wind turbines are nowbeing put up as community projects.

The new market segments of electricity fromsolar, wind and biomass may still only berelatively small players, but they are growingvery quickly. At the moment, furtherchanges in energy policies may shift powerproduction further into the control of corpo-rations, especially if Germany’s feed-in ratesspecified in the Renewable Energy Act arefundamentally revised.

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Figure 10.6 The Solar Age: The end of power monopolies? The share of private powergenerators as of 2004 in Germany

Source: Authors’ depiction based on VDW-Projektgruppe Strombilanzen, 2006

Photovoltaics Wind power Hydropower Biomass

542 25,214 3,611 6,974Share ofelectricitygenerated byprivate citizensin millions ofkWh

Power from private systems (including mining companiesand production industry)

Power from utility plants

96% 99%

17%

73%


11.1 Research funding – notmuch money for the sun

Germany has helped fund energy researchacross the following fields:1

• Fossil energy and power plant technol-ogy (extraction and refinement of coaland other fossil energy sources, firingtechnology, coal liquefaction and gasifi-cation, etc.).

• Nuclear technology (reactor safety,storage of radioactive waste, etc.).

• Nuclear fusion.• Renewables and energy efficiency (the

photovoltaics, wind power, biomass,geothermal, fuel cells, energy-savingindustrial processes, heat storage, etc.).

From 1956–1998, the German ResearchMinistry devoted some €23 billion to energyresearch. Funding was only provided forrenewable energy and energyefficiency/conservation after the first oilcrisis, i.e. starting in 1974. By then, theGerman Research Ministry had already spent€2.6 billion researching nuclear energy. Thedistribution of funds for energy researchfrom 1974–1999 is shown in Figure 11.1.2

The chart clearly shows the following:

• At nearly €15.3 million, the Germangovernment spent nearly five times asmuch researching nuclear energy than itspent on renewables and energy effi-ciency/conservation.

• Even after the 1992 UN Conference onthe Environment and Development inRio de Janeiro, which called for sustain-able economics, research expenses fornuclear power remained far above thefunding for renewables research.

• For many years, the amount of moneyspent on fusion research has beenroughly equivalent to the funding forrenewables even though experts do notbelieve that a fusion reactor will beworkable before 2050. Furthermore, it iscompletely unclear whether any fusionreactor will ever be able to provide elec-tricity at competitive prices.3

From 2001–2003, Germany provided anadditional €51 million per year for researchinto renewables and energy efficiency aspart of its Future Investment Programme.This research covered such things as fuelcells, drive technologies powered by renew-able energy, geothermal, offshore wind,high temperatures solar thermal and energy-optimized construction.4

In the 5th Energy Research Programme, thefollowing funding was set aside for2005–2008: €460 million for fusion; €421million for renewables (including bioenergy);€455 million for efficient energy conversion;and €219 million for nuclear energy (safetyand storage research).5 The funding fornuclear research has clearly been reduced,but more money was still provided for fusionthan for research and development relatedto renewables.

Within the EU, research funding still clearlyfavours nuclear energy. In the 6th ResearchFramework Programme from 2003–2006,two thirds of the budget went to nuclearresearch.6 In the 7th Research FrameworkProgramme from 2007–2011 €2.7 billion isdedicated to nuclear research.7

11

11 Promoting Renewable Energy


167

Promoting Renewable Energy

11

Figure 11.1 Federal funding for energy research in Germany

Source: Authors’ depiction based on Energieforschungsprogramm der Bundesregierung, Berlin, 2005

Research funding in the millions of euros per year1,000

750

500

250

0

74 76 78 80 82 84 86 88 90 92 94 96 98 99

Year

NuclearFusionFossil energySolar and efficiency

Current energy research funding inmillions of euros (2005–2008)

Nuclear energy (nuclear safety and finalstorage)Fusion researchRenewables (including bioenergy)Efficient energy conversion

219

460

421

455


11.2 Start-up financing isneeded

Because many types of renewable energyare not yet competitive with the prices of(subsidized) conventional energy sources,political support is needed for the transitionto the Solar Age. Only the widespread use ofnew technologies can reduce costs andprovide incentives for further development.The reliability of political support is especiallyimportant, for without it companies will bereluctant to make new investments, set upnew sales channels, train staff to reduceinstallation time and streamline production.In return, practical experience from thewidespread use of renewables will promotefurther development.

Such a self-supporting trend was attainedfor wind power in the 1990s. The goal ofenergy policy therefore has to be to bringabout and maintain self-sustaining furtherdevelopment with other renewables. In along-term solar scenario from 1997,8 agroup of experts forecast that some €39billion would be needed by 2010, but theenergy costs that would be offset amount to€29 billion. In other words, some €10 billionin start-up financing would save around€700 million per year over 14 years in thisscenario.

At first glance, €700 million a year mightseem like a lot, especially in light of currentbudget deficits. Yet, far greater subsidies arealready made available in energy policy (seeFigure 11.2). In 2005, the subsidies fordomestic anthracite in Germany amountedto around €2.7 billion,9 and the tax exemp-tion for kerosene is equivalent to some €8billion each year.10 In comparison, Germany’simportant 100,000 Roofs Programme topromote photovoltaics only cost around€100 million a year.11

In 2000, Germany’s Renewable Energy Act(EEG) found a way to provide sufficientfunding to grow renewables without being aburden on the state budget: feed-in rates.For instance, in 2004 some €3.6 billion infeed-in rates was paid.12 The value of thepower sold to the grid that year (38.5 billionkilowatt-hours) amounted to around €2.3billion,13 leaving us with a cost of around€1.3 billion, a figure that has been risingsince. But because these feed-in rates gener-ally automatically drop over time (systemsconnected to the grid at a later date receivelower compensation), the total cost of feed-in rates is expected to start dropping inaround 2015.

In light of the positive environmental effectsthat renewables have and in light of thetremendous subsidies in conventionalenergy, it is not hard to justify this start-upfinancing.

What we still do not know is how to provideeffective start-up financing for solar heat inthe best way. One way could be the methoddescribed in 11.15. If renewables are tobecome competitive with fossil energy,ecological tax reform must be continued andimproved (see 11.4).

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Figure 11.2 Annual subsidies in the energy sector

Source: The authors

Subsidies for coal in Germany in 2005

Forgone tax revenue from exemption on kerosene in 2005

Current solar funding (German Market Incentive Programme 2005)

100,000 Roofs Solar Power Programme (1999–2003)

For comparison: Costs for EEG feed-in rates (2004)

2,700 million €

8,000 million €

200 million €

100 million €

1,300 million €


11.3 Internalizing external costs

Energy is relatively affordable for individuals,but energy consumption can cost societydearly. A study14 conducted by Prognos onbehalf of the German Economic Ministryback in 1992 found that current pricingwould eventually reduce, if not completelyundermine, our prosperity.

• The environmental damage from ourcurrent energy consumption (acid rain,human health, oil disasters, nucleardisasters and the greenhouse effect) iscurrently not priced in. The costs areincurred either during production orconsumption, but they are not coveredby those who caused them. Instead, thisdamage – also called ‘external costs’ – ispaid for either by certain segments ofsociety or by society as a whole (forinstance, when harvests are reduced,insurance premiums are raised or taxesincrease).

• In October 2006, British economist SirNicholas Stern published a study thatdrew a lot of attention. Based on simula-tions, he found that the costs and risksof climate change would reduce globaldomestic product by at least 5 per cent ifwe continue with business as usual. If wetake a wider spectrum of risks and theirconsequences into account, the reportfound that the damage might evenincrease to 20 per cent or more of globaldomestic product.

Clearly, energy is sold at prices below what itshould actually cost. As a result, moreenergy is consumed than is necessary; moreinvestments in efficient appliances andrenewable energy would be made if externalcosts were included in energy prices.

Indeed, the external costs of human activitynot contained in market prices can evenexceed production costs.

Back when Prognos was working on itsstudy, the Fraunhöfer Institute for Systemsand Innovation Research found that conven-tional coal plants entail enormous costs notincluded in power prices. The researchersassumed that the coal plants under investi-gation have scrubbers in compliance withthe standards that still apply today.Specifically, they found that a kilowatt-hourcaused societal costs ranging from 1.6–6.5eurocents per kilowatt-hour; this amount isnot included in power prices. In other words,power generated with fossil energy causessome €4.5–19 billion of damage each year inGermany, and those costs are covered bysociety as a whole.15 What kind of sensedoes it make from the perspective of ournational economy to sell energy cheaplyupfront so that we have to pay for it dearlyafterwards?

The external costs of nuclear power are evengreater when we include their societal costsand risks.16

The exclusion of external costs not onlymeans that too much energy is consumed,but also that investments are made on thebasis of these incorrect prices. Our currentenergy supply strategy, with its allegedly lowcosts, can in fact entail much higher totalcosts for society than a solar economy,which may have greater internal costs at themoment, but will always have very lowexternal costs.17 If we stick to our currentprice system, we will simply be continuingthis large-scale mismanagement. Germanyhas taken a step in the right direction withits Ecological Taxation Reform and theRenewable Energy Act, but we havecertainly not gone far enough.

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Figure 11.3 External costs of nuclear energy

Source: Solar-Fabrik AG

Why OfficerAdam dreamsof the Sun

Officer Adam has an unenviable task.Once again, he has to protect a traintransporting nuclear waste. But thistime, the effort requires more policeofficers than ever, and the event willcost the public around 50 million euros.

Yet, the police would not need to betied up with such things if we usedsolar energy instead. Solar energy isenvironmentally friendly and cannot beexhausted. Most importantly, it doesnot produce radioactive waste.

For the price of one shipment ofnuclear waste, we supply 100,000square meters of solar panels. Enoughto provide Officer Adam and 4,000 ofhis colleagues with electricity – forseveral generations.

The time is right for the Sun. Thereasons are also obvious. Get involved.


11.4 Ecological taxation reform– protecting jobs and theenvironment

In most cases, electricity and heat fromrenewable sources are still more expensivethan conventional power and heat forvarious reasons:

• The external costs of the consumption offossil fuels are not included in the price(see 11.3).

• Some of the technologies for renewablesare still being developed, and large-scaleproduction – which would bring costsdown – is not yet ready.

• When renewables are used, new tech-nologies replace fossil energy. Thisrenewable technology largely entailsmanual labour, which is very expensive inGermany and other industrial countries,partly because it is highly taxed.

• Fossil energy and nuclear energycontinue to receive generous subsidies(see 11.1 and 11.2).

This is where ecological taxation reformcomes in. A tax on fossil and nuclear energyand other raw materials with environmentalimpact makes the use of these materialsmore expensive, thereby indirectly makingthe production of efficient equipment andrenewable energy less expensive in compari-son.

A switch from fossil energy to renewableenergy and efficient technologies results in anumber of positive effects:

• Toxic emissions and emissions of heat-trapping gases (especially CO2) dropwhen less fossil energy is consumed.

• Our dependence on fossil energy, whichis very great in Germany and in the EU asa whole, is reduced.

• Because the growth of renewablescreates more jobs than are lost when lesscoal, oil and natural gas are consumed(see 10.5), jobs are created.

• Lower unemployment rates reduce thesocial cost of unemployment when thestate does not have to spend as much onunemployment benefits, does not loseso much tax and Social Security revenue,and does not have to cover illnessbrought about by unemployment.

One common misconception about ecologi-cal tax reform (ETR) is that it raises theoverall tax level. In fact, the very concept ofETR is that the tax level be kept the same.The goal is to shift taxation from labour,which we want to have and is available insufficient quantities, to scarce resources,which we want to use efficiently.Furthermore, properly designed ETR alsoensures that the poor are not detrimentallyaffected, which was unfortunately not thecase in the first stages of ETR in Germany.

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Figure 11.4 How ecological tax reform works

Source: The authors

Higher taxes onnatural products

Lower environmental

impact

Lower external costs

Lower payroll taxes

More jobs

Lower social costs(such as

unemployment)

Overall tax burdenremains unchanged

Higher standard of living

Reduction of costs to society

Ecologicaltaxationreform


11.5 Ecological taxation reformin increments

On 1 April 1999, Germany began its ecolog-ical taxation reform. A tax was added tofuels, electricity, natural gas and heating oil,and the surcharge for power and fuels wasincreased each year for five years.

The tax ratesStarting with a tax rate of 1.02 eurocentsper kilowatt-hour on electricity (April 1999),the tax was increased by 0.26 eurocents perkilowatt-hour at the beginning of the nextyear. In January 2003, the last stage beganwith the fourth tax hike. Overall, the tax onelectricity for households and small busi-nesses amounts to 2.05 eurocents perkilowatt-hour.

Up to the end of 2002, businesses involvedin production, agriculture and forestry paid a20 per cent lower surcharge.18 Energy-inten-sive large firms could receive even largerreductions. Since 1 January 2003, businessesinvolved in production, agriculture andforestry have paid 60 per cent of the totalrate, equivalent to 1.23 eurocents per kilo-watt-hour.

The surcharge on fuels (gasoline and diesel)was increased by 3 eurocents per litre eachyear; it currently amounts to around 15eurocents per litre.

There is no tax on natural gas and heating oilwhich is burned in cogeneration units19 topromote power generation in such units.

Overall, some €20 billion in tax revenue wascollected and devoted to stabilizing andlowering rates for pension funds, i.e. non-wage labour costs were offset.

Ecological taxation reform raised energytaxes in predefined increments, allowingconsumers and businesses to take futurechanges into account when decisions aremade about consumption and investments.Cars with better gas mileage, home insula-tion, efficient appliances and energyefficiency in production all pay for them-selves faster thanks to ecological taxationreform.

Three studies on the effects of ecologicaltaxation reform on the environment and thejob market found that ecological taxationreform was effective. Some 250,000 newjobs were created, and 20 million tons ofCO2 was offset.20

Nonetheless, ecological taxation reformmust be continued and further optimized.Climate change and scarce fossil resourcesare worsening faster than expected.Additional stages of ecological taxation areneeded to ensure that investments todayprepare us for the necessities of tomorrow.

Figure 11.5 shows the trend in demand foroil if we switch to a renewable energysystem over the long term. Without ecolog-ical taxation reform, demand skyrockets, butif we increase taxes on fossil energy demanddrops considerably. Here, the financing forrenewable energy is easier to get.

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Figure 11.5 Eco-taxes reduce start-up financing for renewable energy

Source: Langniß et al, 1997

Required startup financing

Overall need for funding (depending on energy prices)

With constant energy prices

With slightly rising energy prices (+2 per cent per year forelectricity, +4 per cent per year for oil and gas)

With quickly rising energy prices (+3 per cent per year forelectricity, +5 per cent per year for oil and gas)

2000 2015


11.6 Investment bonuses forsolar thermal systems

In the 1990s, widespread support wasoffered for solar thermal systems inGermany. By 1997, the country had installednearly 200,000m2 of collectors, with theGerman states providing 77 per cent of thebonuses.21 Surveys showed that most of thesystem owners would not have installedtheir systems yet without this support.22 Thebonuses clearly led directly to these invest-ments. At the same time, these campaignsalso clearly ramped up the market; mostGerman solar installers said they installedtheir first solar thermal arrays between 1992and 1996.23 Overall, these campaignsreached their goals. A large number of newsolar thermal systems were installed, techni-cal expertise became widespread, and pricesdropped.24

In the light of types of governmentalbudgets, the design of efficient supportstrategies for the future is especially impor-tant, as we see below based on the exampleset by two German states: Hessen andBaden-Württemberg.

From 1992 to 1995, both of these Germanstates provided investment bonuses for solarthermal systems. Baden-Württembergoffered about DM2000 deutsche marks(€1022) per single-family home, whereasHessen offered up to DM3000 (€1534, butnot exceeding 30 per cent). The number ofsystems installed grew by 77 per cent inHessen and 193 per cent in Baden-Württemberg.25 Clearly, this policy led togreat market growth in those years.

In 1996, things changed when specialfederal funding was provided for solarthermal systems on new buildings. Hessenresponded by changing its support; tocompensate for the lower system costs,support was cut by a third, and funding wasconcentrated on existing buildings. Despitethese two restrictions, the number of solarthermal arrays that took advantage of thesebonuses increased by an additional 14 percent from 1995–1997. Overall, this strategywas efficient and successful.

In Baden-Württemberg, the governmentchanged in 1996. The new centre-rightcoalition turned the solar bonuses into low-interest loans that could be used incombination with the federal bonus. Theoutcome was very different. Up to then,most solar investors had been homeownerswho wanted to do something good for theenvironment with their savings and tookadvantage of the bonus. Loans were of nointerest to them. The loans were thereforeonly used for new buildings in combinationwith the federal funding, and the volumewas low. As a result, the solar market plum-meted. From 1995–1997, the collector areainstalled with this funding dropped by 54per cent (roughly down to the level of 1992,see Figure 11.6), while the number of solarthermal arrays nationwide grew by morethan 40 per cent.26 This politically motivatedswitch pulled the rug out from under thesolar sector.

At present, Germany provides investmentbonuses for solar thermal systems from itsMarket Incentive Programme.

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Figure 11.6 Upfront bonuses for solar thermal more effective than loans

Source: Landtag Baden-Württemberg, 12/1840, 3635

Funding for solar thermal arrays in Baden-Württemberg

Supported collector area in m2

40,000

30,000

20,000

10,000

0

Funding isswitched toloans

1992 1993 1994 1995 1996 1997 1998

The market collapsed in 1996 when the incentive to promote solar thermalsystems was switched from upfront investment bonuses to low-interest

loans in the state of Baden-Württemberg. In contrast, the market grew bymore than 50 per cent thoughout Germany from 1995 to 1997.


11.7 Solar energy in rentalapartments – a problemchild

A solar strategy restricted to user-ownedproperty does not go far enough. Mostmulti-family dwellings and rental complexeswould remain unaffected. Yet, such build-ings offer tremendous potential forinexpensive solar heat. On the one hand,large collector areas reduce the cost per kilo-watt-hour; on the other, the large number ofusers means there is always demand.Systems then have better capacity utiliza-tion, and the useful energy yield per squaremetre of collector increases.

Despite these clear benefits, solar thermalsystems are rarely used on multi-familydwellings and rental complexes; at present,more than 90 per cent of all such systemsare installed on single-family dwellings andduplexes. One main reason is theowner/user conflict: building owners are theones who have to make the upfront invest-ment in solar arrays, but tenants are theones who benefit when utility costs godown. Landlords can only raise the rent tocover the investment, as is done for otherrenovation work. Because there is no speciallegal basis for such renovations, few land-lords take advantage of the option. Instead,landlords and housing management firmssimply do without solar energy, leaving thepotential of solar power largely untapped onsuch properties.27

Solar heat contractors are one option. Here,landlords/housing managers have the servicecompany install and operate the solar array(and possibly the heating system). Based onthe difference between investment costsand operating costs, the contractor thencalculates the price for heat that can bepassed on to the tenant. This business model

gets around the owner/user conflict and isbecoming a common service offered inGermany, such as by Berlin’s EnergyAgency.28 In addition, the price of solar heatmust continue to be brought down to aprice that is competitive on the market.

For the transitional period until solar arrayspay for themselves without any specialfunding, there are various ways to promotethe use of solar thermal and apartmentcomplexes. On the one hand, specialfunding can be provided;29 on the other,building codes can make the use of solarthermal systems mandatory. The first optionwas first implemented in Berlin. The city’ssenate resolved in its Solar ThermalOrdinance of 1995 to require the installationof solar thermal arrays to cover 60 per centof annual heat consumption in all new build-ings with central heating systems.30 Housingassociations fought against the regulationand the government decided not to enforcethe ordinance.31 But the city of Barcelona,Spain, has since had greater success with asimilar ordinance (see 11.14).32

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Figure 11.7 The problem child: Solar energy for tenants

Source: The authors

The owner/user dilemma(here, taking the example of solar thermal arrays for

rented apartments)

Tenants

enjoy the benefits(hot water fromthe Sun)

Landlords

pay for theinvestments butcannot necessarilypass on all of theextra costs

Solutions:

– special funding for solar in the rental sector– solar heating contractors– mandatory solar thermal arrays on new buildings

as part of building code


11.8 Compensation for solarpower with a return oninvestment

Before feed-in rates were offered for solarpower starting on 1 April 2000, there was atremendous difference between the cost ofsuch systems and the amount paid for solarpower. In 1999, around 8 eurocents perkilowatt-hour was paid for one kilowatt-hour. If array owners sold all of their powerto the grid, they would get just under €1500over 20 years for a 1 kilowatt-peak system(20 years at 900kWh/year at 0.08 €/kWh =€1440). But back then, such a system wouldhave cost around €10,000 and thereforenever have even come close to paying foritself.

To provide a proper return, the Solar EnergyAssociation of Aachen came up with theidea of offering feed-in tariffs for solarpower at the beginning of the 1990s. Thecost of a kilowatt-hour of solar power froma properly installed array would then providea slight profit margin in addition to coveringinvestment costs and operating costs. Therates were specified at the time of gridconnection for a period of 20 years. Andbecause the cost of new solar powersystems was dropping (see 3.5), newlyinstalled systems would receive slightly lowerfeed-in tariffs. At the end of the 1990s,some 90 eurocents per kilowatt-hour waspaid.

Feed-in tariffs differ from other supportprogrammes common at the time in onecrucial respect: the funding does not applyto the installation of the system itself, butrather to the power produced. This systemhas a number of clear advantages:

• Money is only paid if the system actuallyproduces electricity. Here, the incentive isto get the system back up and runningwhenever there is a malfunction.Because owners have to pay the invest-ment costs themselves, there is anincentive to keep them down. As aresult, prices drop.

• The funding does not come from thepublic budget; rather, utilities pass thecosts on to all power consumers, insur-ing that the programme remainsimplemented when politicians look forthings to cut from the budget.

The principle behind feed-in tariffs is basedon one already applied by utilities, whocalculate the retail electricity rate based onvarious costs of different kinds of powerplants. When solar power is added to thesources of electricity, power prices onlyincrease slightly.

In 1999, some 20 municipal utilities offeredfeed-in tariffs. None of the large conglomer-ates did. Figure 11.8 shows that feed-intariffs for solar power gave photovoltaics atremendous boost in the beginning.

The basic idea behind feed-in tariffs is togive investors in solar power systems areturn on their investment, an idea that waslater adopted in the Renewable Energy Actwhen it was revised in 2004.

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Figure 11.8 Feed-in rates for solar power get photovoltaics started in Germany

Source: Solarförderverein Aachen

Installed photovoltaic capacityper customer in Watts

22

20

18

16

14

12

10

8

6

4

2

0

In comparison,RWE’s Green Powerrates and KESS andall of RWE’s arraysin Germany at the

launch of theprogramme on

July 1, 1996

1 A

ug 9

3

17 D

ec 9

3

1 M

ay 9

5

12 M

ay 9

5

19 J

un 9

5

1 Ju

l 95

1 A

ug 9

5

1 Ja

n 96

1 Ja

n 96

1 Ja

n 96

1 Ja

n 96

1 Ja

n 96 1 Ja

n 96

1 Fe

b 96

1 Ju

n 96

1 N

ov 9

6

Beginning of programme

Photovoltaic arrays– before feed-in rates (front row)– after feed-in rates (back row, end of 1998)

Freis

ing

Hamm

elbur

gRe

msc

heid

Soea

stAac

hen

Lam

goBo

nnGüt

erslo

hHalt

em Roth

Fürst

enfe

ldbr

uck

Nurem

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Blom

berg

Pfor

zheim

Lübe

ckW

edel

RWE


11.9 From the Feed-in Act to theRenewable Energy Act(EEG)

The rollout of the Feed-in Act at the begin-ning of 1991 marked a turning point in thehistory of wind power in Germany. For thefirst time, grid operators were required bylaw to pay a floor price for renewable powersold to the grid. The rates paid were basedon the average power prices for all retailcustomers in the previous year.

Grid operators were obligated to pay 90 percent of that figure for electricity from windpower and solar arrays, 80 per cent forpower from biomass and small hydrostations with a capacity up to 500kW, and65 per cent for power from hydro plantswith a capacity ranging from 500kW–5MW.

For instance, Germany’s Bureau of Statisticscalculated that the average price per kilo-watt-hour in 1997 was 9.4 eurocents, so therate paid for wind and solar power in 1999was 8.4 eurocents per kilowatt-hour. In2000, 0.2 eurocents less was paid for a kilo-watt-hour of wind power because theliberalization of the power market hadbrought power prices down in most areas,thereby reducing the base price for 2000.

Potential investors were unsure about whatfeed-in rate they would get in the future fortheir renewable power. To provide moreclarity and hence more investment incentivesfor renewables, feed-in rates were madeindependent of the retail rate when the lawwas revised.

Another change was brought about by therevision of the Energy Act in the version thattook effect on 29 April 1999. Legislatorshave adopted a special rule for the Feed-inAct, stipulating that utilities no longer had tocompensate for power if the renewableenergy exceeded 5 per cent of the utility’stotal power sales, with the obligation fallingon the supplier between the utility and theproducer. And if the supplier in-betweenalso had 5 per cent renewables in its totalsales, it also did not have to pay for anyadditional power.

This rule – called the ‘duel 5 per cent ceiling’back then – was introduced in order to limitthe financial burden on individual powerproviders. By then, a large number of windturbines had been installed on the northernGerman coast, so power distributors in theseareas were more affected by the law thanother power companies.33

But this ceiling was not a good way to solvethe problem, and it would have sloweddown the further growth of the windmarket. So when the law was revised in2000, the Renewable Energy Act did awaywith that rule (see 11.10).

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Figure 11.9 From the Feed-in Act to the Renewable Energy Act

Source: BMU, Erneuerbare Energien in Zahlen, 2006

Feed-in rates in themillions of euros

TWh/a sold to the grid

Feed-in rates under theFeed-in ActFeed-in rates under theRenewable Energy Act

1991 1993 1995 1997 1999 2001 2003 2005

5,000

4,500

4,000

3,500

3,000

2,500

2,000

1,500

1,000

500

0

60

50

40

30

20

10

0

Compensation


11.10 The Renewable EnergyAct (EEG)

From both an ecological and economicalviewpoint, the Feed-in Act (see 11.9) neededto be revised after the liberalization of thepower market. Its successor was theRenewable Energy Act (EEG), which cameinto force on 1 April 2000. The EEG wasrevised in 2004, with feed-in rates beingadjusted.34 This law differs in a number ofimportant ways from the Feed-in Act of 1991:

• The feed-in tariffs are originally paid outby network operators, but the fees paidare later equaled out at the national levelbetween network operators so that allnetwork operators and power customersare equally affected.35

• The rates paid are no longer linked to theretail power rate, but rather vary accord-ing to the type of renewable energy inquestion in order to allow for a return oninvestments in renewable systems runproperly. The rates paid remain constantfor 20 years.36

• To ensure that the rates keep up with thefalling cost of renewables, the compen-sation for solar arrays, wind turbines andbiomass facilities decreases automaticallyaccording to a calendar schedule (called‘degression’ in financial jargon);compensation remains stable, however,for 20 years once a system is installed.

The EEG has the following floor prices forfacilities that went into operation in 2007:

Hydropower: Here, 9.38 eurocents per kilo-watt-hour is paid for systems up to 500kW,whereas systems with an output of501–5000kW receive a floor price of 6.45eurocents per kilowatt-hour.37

Biomass: Here, compensation also dependsupon the size of the system, with 10.99

eurocents per kilowatt-hour being paid forsystems up to 150kW, 9.46 eurocents perkilowatt-hour being paid for systems up to500kW, 8.51 eurocents up to 5MW, and8.03 eurocents for larger systems.38 The floorprice increases if power mainly comes fromrenewable resources in a cogeneration unit.39

Wind power: The floor price for systemsconnected in 2007 is 8.19 eurocents perkilowatt-hour in the first five years. Afterthat, compensation depends on the qualityof the location. In good locations, only 5.18eurocents is paid starting in the sixth year,but the rate is not reduced at all in worselocations. The annual degression for systemsconnected at a later date is 2 per cent. Therules for offshore systems also differ.40

Geothermal: The rates paid for power fromthe geothermal systems also depend uponsystem size, ranging from 15 eurocents perkilowatt-hour in systems up to 5MW downto 7.16 eurocents per kilowatt-hour insystems larger than 20MW. The annualdegression is 1 per cent starting in 2010.

Photovoltaics: The greatest improvementshave been made in photovoltaics. Instead ofthe 8.5 eurocents that used to be paid underthe Feed-in Act for a kilowatt-hour of solarpower, now rates between 51.8 eurocents(solar façade) and 37.95 eurocents (ground-mounted systems) are paid. Starting in2006, compensation drops automatically by6.5 per cent per year for new ground-mounted arrays.

The EEG has given investors a fair, reliableframework and led to a boom in renewableenergy. At the beginning of 2010, the newgoverning coalition in Germany proposeddrastic one-off cuts in the feed-in tariffs forsolar power. For the current tariffs, seehttp://de.wikipedia.org/wiki/Erneuerbare-Energien-Gesetz.

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Figure 11.10 The Renewable Energy Act: Feed-in rates for new systems connected to thegrid in 2007 (eurocent/kWh)

Source: The authors

up to 150 kW up to 500 kW up to 5 MW >5 MW

Hydropower1 9.38 9.38 6.45 special rule

Waste and mine 7.33 7.33 6.36 special rulegas2

Biomass2 10.99 9.46 8.51 8.03

up to 5 MW up to 10 MW up to 20 MW >20 MW

Geothermal3 15.00 14.0 8.95 7.16

up to 30 kW up to 100 kW >100 kW

Photovoltaicson roofs and noise 49.21 46.81 46.30barriers4

as solar façades4 54.21 51.81 51.30ground-mounted5 37.95 37.95 37.95 special rule

No project ceiling

Wind power6

Onshore 8.19 for at least five years (max. 20 years), Offshore 9.10 5.18 c/kWh afterwards for at least 12

years, special rule

Automatic annual rate reductions 1 1.0 4 5.0for systems connected after 2007 2 1.5 5 6.5in % 3 1.0 6 2.0

(starting in 2010)


11.11 The EEG as a model forother countries

Germany’s Renewable Energy Act (EEG) hasnot only brought about a boom in renew-able power in Germany, but also led anumber of countries to copy Germany’ssuccess in their own legislation; not onlyGerman wind power and solar power equip-ment, but also the policy itself has become ahot export item.

In addition to practically all of Europe – fromSpain to Portugal, France, Austria, Ireland,The Netherlands, Greece, Italy and the UK –countries such as Thailand and Pakistan havealso adopted this model, as have regionssuch as Ontario, Canada and the US state ofVermont. China also now offers feed-in ratesfor renewable energy, including biomass andsolar energy.

A growing number of countries are adoptingfeed-in rates. At the beginning of 2006, theGlobal Status Report found that 41 coun-tries and states had adopted feed-in rates.41

Often, these feed-in rates are part of apackage of policy instruments.42 In 2009, atleast 64 countries now have some type ofpolicy to promote renewable power genera-tion.43

Since 2010 Britain also has a feed-in tariff.The programme, like the successfulprogrammes it was modeled after, wasdesigned to ‘set tariffs at a level to encour-age investment in small-scale, low-carbongeneration.’44

The global boom in renewable energy canbe expressed in system capacity or, perhapseven better, in dollars and cents. Total invest-ments in renewables only amounted toUS$30 billion in 2004, but that figure hadincreased to US$120 billion in 2009.Renewables have clearly become a sectorworth billions, and the industry is growingfar faster than other industries.

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Figure 11.11 German feed-in rates abroad: Countries with feed-in rates for renewableelectricity

Source: The authors


11.12 Photovoltaic arrays as a‘blight’ on the landscape

Under the feed-in rates paid in Germany, it isattractive for investors to set up ground-mounted arrays in the field. Such systemsoffer a number of benefits.45 On the onehand, there are economies of scale; on theother, solar cells can be oriented optimally toface the sun, and the modules do not heatup as much when they have air behindthem, which increases overall efficiency.Furthermore, maintenance is easier to do onthe ground than on roofs or façades.

Some concerns about nature conservationare unfounded. For instance, the standsused to install the panels do not haveconcrete foundations and do not seal thesoil. And the shade cast by the panels moveswith the sun just like it does with trees, sothe land under the solar panels can still beused for grazing.

But one major bone of contention is thecharge that large ground-mounted arraysare a blight on landscapes. The argument issimilar to the one against wind turbines.46

German law was therefore revised in 2004to provide a greater incentive for solarpower on buildings, where plenty of space isstill available, but field systems are still possi-ble. From 2004–2009, roughly 12 eurocentsper kilowatt-hour more was paid for build-ing-integrated solar arrays than forground-mounted systems (see 11.10). Inspring 2010, the German governmentproposed to completely do away with feed-in tariffs for ground-mounted arrays onfarmland; in addition, support for arrays onbrownfields would also be drastically cut.

SitingFeed-in rates are only available, however, ifthe solar array is approved in the local landdevelopment plan. Since 1 September 2003,land development plans have included sitesset aside for solar arrays. The public isinvolved in the process to ensure the great-est possible public acceptance. Oneconsequence of this policy is that solar arrayscannot be built on land against a commu-nity’s wishes.

Site restrictionsFeed-in rates are only paid if the solar arrayis on disused or contaminated land, includ-ing disused farmland, which can be madeecologically valuable again if a solar array isinstalled.47 One example of such a ground-mounted array is the 3.4MW solar plant inBorna, Saxony, where 22ha of a former coalbriquette plant was converted (see Figure11.12).48 Since German law does not provideany special compensation for solar arrays onnormal green areas, much less ecologicallysensitive land, solar arrays are not installedthere. Without feed-in rates, systems in suchareas would never pay for themselves.

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Figure 11.12 Solar on disused land

Source: Geosol Gesellschaft für Solarenergie mbH

In 2006, a 3.44MWp solar array was installed on the grounds of a formercoal briquette plant in Borna


11.13 Quotas and requests forproposals

There are generally two policy designs topromote renewable power production. Thefirst is floor prices for power sold to the grid(see-in rates). Here, the market decides whatthe volume is; if the floor price is highenough, a lot is invested, but if the floorprice is too low, little or nothing is invested.

The second type of policy does not set theprice, but rather the volume in quotas orrequests for proposals.

When quotas are imposed, utility companiesare obligated to get a certain percentage oftheir power sales from renewable sources.Power generators get certificates to demon-strate that they have sold a certain unit ofrenewable power (such as a certificate for10,000kWh). Companies that produce morethan the quota requires can sell certificatesto those who do not produce enough. Theprice for the certificates depends on supplyand demand. Quotas require a regulatorybody, which monitors the issuing of certifi-cates and imposes penalties if quotas are notfulfilled.

In requests for proposals, the policy stipu-lates a target volume, such as additionalannual wind power production of 300GWh.Investors can then submit proposals forsome of that volume, and the least expen-sive bidders get the contracts.

Proponents of such policies consider themmore efficient than feed-in rates becausethey are allegedly more competitive, andonly the cheapest projects go online.

Are they right? Without a doubt, they are intheory. But in practice, volume-based poli-cies have more often discouraged thanencouraged the growth of renewables.

While Denmark and Spain have had a grandsuccess expanding their renewables marketswith floor prices, the UK, Ireland and Francedid not go anywhere with their quota poli-cies, which is why they have all switched tofeed-in rates.

Although we cannot compare these twopolicy types in detail here, a decade of dataclearly shows that countries with floor prices(feed-in rates) installed several times morewind power in 2004, for instance, thancountries with volume targets.

The German state of Baden-Württemberg –roughly the size of Connecticut and withsimilar solar conditions – alone had1074MW of solar online at the end of 2008,producing around 1 billion kilowatt-hours ofelectricity. In comparison, the US had a totalinstalled PV capacity of only 800MW at theend of 2008, a full 25 per cent less than tinyBaden-Württemberg – a fact that the USsolar sector likes to hide by claiming:‘Installed solar power capacity in the US roseby 17 per cent to 8775MW in 2008.’49

However, that figure includes all kinds ofsolar, including pool heating, etc., none ofwhich is included in the figure for Baden-Württemberg.

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Figure 11.13 Quota systems and feed-in rates: Which is more effective?

Source: Bundesverband WindEnergie

Additional installed wind power capacity in 2004

50.47 Spain 2,065

24.59 Germany 2,037

23.86 Austria 192

12.2 Netherlands 197

22.21 Portugal 226

8.47 Greece 90

3.83 Italy 221

4.05 UK 240

2.32 France 138

Watts per inhabitant In megawatts

Countries with floor prices (feed-in rates)

Countries with quota systems


11.14 Solar thermal arraysrequired on new buildings

In Germany, a Market Incentive Programmehas promoted solar thermal arrays and woodpellet heating systems over the past fewyears. Rising oil prices brought abouttremendous growth here, but the growthalso put a strain on public budgets (whichwere financing these investment bonuses).Nonetheless, renewable heat still did notgrow as fast as renewable electricity, whichwas supported by feed-in rates. For instance,the share of renewables on the heat marketonly grew from 5.1–5.4 per cent from2003–2005, while the share of renewableelectricity rose from 8.1–10.2 per cent.50

Faster growth is therefore needed in theheating sector if we are to enter the SolarAge.

One way to step up this transition is to makesolar thermal systems mandatory on newbuildings. In Germany, the small town ofVellmar just outside of Kassel was the first totake this step. In 2001, the Osterberg neigh-bourhood required solar thermal arrays in itsurban planning code.51 Some 1000m2 ofcollector area had to be installed on approx-imately 350 new buildings. Hamburg laterwent even further in its Climate ProtectionAct, which required solar collectors in urbanplanning. Some 5500 apartments now get30 per cent of their hot water from solarthermal systems.

In Spain, Barcelona went much further. SinceAugust 2000, the Solar Ordinance52 hasrequired all residential complexes with atleast 16 apartments to get at least 60 percent of their hot water from solar thermalarrays. Swimming pools even have to get100 per cent. This rule does not apply for asingle neighbourhood, as in the Germanexamples, but rather all over the city. In thebeginning, the construction sector opposedthe ordinance, but there is now widespreadacceptance of the mandatory solar arrays.Since the end of 2000, installed collectorarea has grown more than tenfold.53 OtherSpanish communities, including Madrid andSeville, quickly followed suit, and in October2006 a nationwide ordinance took effectwith somewhat lower requirements: all newbuildings and renovation projects mustensure that 30–70 per cent of hot water isprovided with solar energy. The nationalobligation does not override stricter ordi-nances in individual communities.

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Figure 11.14 The success of mandatory solar arrays in Barcelona

Source: Quilisch and Peters, Solarthermie in Katalonien, 2005

Collector area in m2

25,000

20,000

15,000

10,000

5,000

02000 2001 2002 2003 2004

By requiring new buildings to have solar thermal systems, Barcelonaincreased installed collector area more than tenfold from 2000 to 2005


11.15 Feed-in tariffs for heat inGermany?

In 2005, the new coalition under the leader-ship of Chancellor Angela Merkel agreed tofocus on the market potential of renewableheat by continuing the Market IncentiveProgramme with the addition of other policyinstruments such as a Renewable Heat Act.54

In May 2006, Germany’s EnvironmentalMinistry produced a consultation paperlisting four possible models:55

1 Investment bonuses.2 Tax incentives.3 Models of usage (with or without a rule

for compensation).4 The Bonus Model (feed-in tariffs for

heat).

The first two are basically well known policyinstruments that depend upon the currentbudget situation. It is therefore unclearwhether they will be able to provide thenecessary continuity in policy support givenstrong growth.

In the ‘models of usage’, operators ofheating systems and heating networks areobligated to get a certain share (such as 10per cent) of the heat they use or marketfrom renewables. If that is not possible oreconomically feasible, they must apply forexemption. Israel and Spain have alreadyproven the success of this approach (see11.14).

The drawback of this approach is the paper-work. In addition, large systems and districtheating networks, which tend to be lessexpensive, also receive less support.

In the Bonus Model (feed-in tariffs for heat),generators of renewable heat use the heatthemselves or sell it to third parties. For theheat they generate, they receive a bonusspecified by law on top of the priceconsumers usually pay for fossil energy; thebonus covers the additional cost of renew-able heat. The value of the bonus dependsupon the technology used.

Sellers of fossil fuels have to cover thesebonus payments according to their share ofthe market; they pass on these extra costs asa surcharge on the oil and gas they sell (seeFigure 11.15). Operators of small systemsreceive an upfront, one-off investmentbonus instead of ongoing bonus payments.

The bonus model does not depend upon thestate of the public budget and can thereforeprovide reliability. By tailoring the amount ofthe bonus to what each technology needs,special incentives can be created for differ-ent types of district heating networks. Thepublic sector plays a minor role; for instance,it determines market shares and preventsfraud. The bonus payments could befinanced with a slight surcharge on the priceof fossil fuels. The German EnvironmentalMinistry estimated that this surcharge couldamount to around 1 per cent (0.65 euro-cents per litre of oil) in 2010 and that figurewill only rise to 2.5 per cent by 2020.56

Overall, the bonus model provides benefitsfor long-term expansion, and somewhat lesspaperwork is involved than in the model ofuse. As of 2010, the concept had not beenimplemented in Germany.

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Figure 11.15 Proposal for feed-in rates for Germany: Heat providers receive bonus forenvironmental service

Source: The authors

Solar heat generator

Conventional heatgenerator 1

Conventional heatgenerator 2

Conventional heatgenerator N

Additional costfor solar heat andother renewablessource of heat

Cost offossil heat

... and passes those costs onas a surcharge on the price

of fossil fuel.

Covers additional cost of solar heat...

Oil and gas wholesaler


11.16 Emissions trading

A distinction is made between two basictypes of policy instruments in environmentalpolicy: on the one hand, we have command-and-control approaches, which tellcompanies how much they can emit, whatexactly they can emit, and what kind ofequipment may be used; on the other, wehave free-market instruments, such as taxes,levies and emissions trading.

The idea behind emissions trading is to findthe least expensive way of reducing emis-sions of carbon dioxide (CO2) and otherheat-trapping gases. Here, a governmentdecides what the maximum carbon emis-sions can be among emitters (currently onlylarge energy companies) to protect theclimate. These companies then either haveto reduce carbon emissions in their ownplants so they can reach the goal them-selves, or they have to purchase ‘emissionscertificates’ from other companies that havemore certificates than they need. Becausethe overall emissions volume is clear, amarket price for carbon emissions results. Ifthe target is very ambitious, the price forcarbon certificates will be higher than ifcompanies can reach the target withoutgreat investment. Based on the price ofcarbon, emitters will decide whether it ischeaper to change something in-house orpurchase certificates from third parties. Intheory, supply and demand allows carbonemissions to be reduced in the cheapest wayhere. Emissions trading is therefore consid-ered to be economically efficient.

Emissions trading began in Germany in 2005after the EU had adopted its EmissionsTrading Directive in 2003, which obligatedEU member states to begin emissionstrading.57 The EU has insisted on emissionstrading because there was a general consen-sus that the EU would otherwise not fulfill itsobligations in the Kyoto Protocol, in whichthe signatories agreed to reduce their emis-sions from 2008 to 2012 to a certain targetthat differed from one state to another.Overall, the EU agreed to reduce its carbonemissions by 8 per cent over the referenceyear of 1990. Within the EU, the variousmember states have agreed to variousreduction targets; Germany’s is 21 per cent.

The Kyoto Protocol was ratified by thenecessary majority and went into effect on16 February 2005; it is binding under inter-national law.58

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Figure 11.16 How emissions trading works

Source: The authors

Emissions in 1990 as reference value: 100 per cent

Target emissions in 2008:79 per cent

Company A Company B

Emis

sio

ns

Emis

sio

ns

Company A isover the targetvalue and has topurchasecertificates.

Company B isbelow the targetvalue and can sellcertificates.

ExchangeCertificates are sold on the

certificate exchange.


11.17 Clean DevelopmentMechanism (CDM)

In the Kyoto Protocol (see 11.16), the signa-tory states agree to reduce emissions ofheat-trapping gases by specified amounts.The first reduction period runs from2008–2012.

Globally, it does not matter to the climatewhich country reduces its emissions by howmuch. Economically, it makes the most senseto reduce carbon emissions where it coststhe least. To allocate funding most effi-ciently, the signatories to the Kyoto Protocolagreed to use ‘flexible mechanisms’ to reachthe targets. For instance, one country canpurchase emissions certificates from anotherto fulfill its obligations.

Another instrument that can be used bothfor EU obligations and within the KyotoProtocol is the Clean DevelopmentMechanism (CDM). Here, the industrialcountries that have agreed to reduce theiremissions (called Annex I countries) caninstead invest in projects in industrializingand developing nations (non-Annex I coun-tries) and have the emissions reductionscredited to their own home country to theextent that these investments protect theclimate and focus on sustainable develop-ment.

This system is expected to provide animpetus for investments in renewables andenergy conservation in newly industrializedand developing nations. Investment projectsand hydropower, wind power, reforestation(carbon sinks) and methane gas from wastethereby have another source of revenue:proceeds from the sale of carbon certificates(Certified Emission Reduction Units or CER).

Although this instrument can make a differ-ence in climate protection, the CDM doesnot go far enough to help newly industrial-izing and developing nations achieve asustainable energy supply. Other aspects oftheir energy supply systems also have to beimproved, such as feed-in tariffs for renew-able energy, fewer subsidies in the energysupply system, less red tape, etc.

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Figure 11.17 How the Clean Development Mechanism works: An example

Source: The authors

offsets fossilpower

credit note forCO2 certification

invests in wind power

Industrial firmAnnex 1 country

(industrialized country)

Credit for carboncertificates

CDM Executive Boardregisters projects and

certificates

Wind power project

in non-Annex 1 country (developing

countries)


11.18 A cornucopia ofinstruments

Over the long term, renewable energy canand must make up a large part of our energysupply. Growth therefore has to be fast, andthere is no looking back. All of the tech-nologies at our disposal must be promoteduntil they are competitive. The properapproach is to use instruments that providestart-up financing until renewables becomecompetitive on their own.

The important role that Ecological TaxationReform has played alongside Germany’sFeed-in Act, the distribution of researchfunding, feed-in tariffs and investmentbonuses has already been discussed.

In addition, there are other ways of support-ing these policies and adjusting the policyinstruments to specific technologies andtarget groups so that renewables developquickly.

• Targeted marketing raises awarenesswhere it is needed most and clears upmisconceptions. The German EnergyAgency has already taken a few steps inthis direction with its information portaland efficiency campaign.59

• On the supply side, some tradespeoplestill have reservations. Further trainingseminars, such as the Swiss RAVELprogramme60, and nationwide demon-stration projects could help dispel someunfounded concerns.

• To ensure the efficiency of the fundingmade available, individual policy instru-ments must be adjusted both to thepreferred target group and the specifictechnologies to be supported. Systemswith a small investment volume andprivate users are easy to reach withinvestment assistance. Systems with

outputs that are easy to measure (inparticular, power generators connectedto the grid) can easily be paid for withfeed-in tariffs.

• To provide incentives for fast investmentsin renewables, the rates offered shoulddrop into the future. Furthermore, a setamount is better than a percentagebecause the former puts greater pressureon manufacturer costs.

The most important thing about successfulsupport, however, is continuity and reliabil-ity. Nothing is worse for the growth ofrenewable energy than announcementsabout new policies that are then postponedor sorely underfunded, so that only thepeople at the front of the line are served.This effect is even worse when investmentsupport entails a lot of red tape and iscontingent upon a construction permit forthe project before financing can be finalized.

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Figure 11.18 Using different policy instruments

Source: The authors

Feed-in Upfront Low- Operating Risk fundrates bonuses interest costs

loans bonus(FITs for heat)

Small hydropower � �Wind power �Photovoltaics � � �Small solar collector arrays �Large solar collector arrays � �Electricity from � �biomass

Heat from biomass � � �Geothermal � � � �


11.19 Phasing out nuclear

The 1986 reactor catastrophe in Chernobylfinally made everyone realize what the risksof nuclear power are. But climate changehas since made it clear that our currentenergy supply system also poses tremendousrisks. The energy sector is taking advantageof this new situation to play one risk offagainst the other; in the process, nuclearenergy is now being sold as a way to combatthe greenhouse effect. After all, the argu-ment goes, nuclear energy offsets fossilenergy, thereby reducing carbon emissions.

While correct on the surface, this claimleaves out a number of important issues. Forinstance, under the Schroeder governmentGermany resolved to decommission itsnuclear plants after 32 years of service.While we are waiting for the remainingplants to be shut down, power providershave a great incentive to increase sales inorder to keep future technologies fromgetting started. As a result, they are nottelling people how to conserve energy,which would lower demand, nor are theyimplementing renewables themselves.

If Germany shut down its nuclear plantssoon, the result would be great innovationand production in new energy technologies.The markets for sustainable energy tech-nologies would grow quickly, which beliesthe claim that we would only increasecarbon emissions by doing away withnuclear power. In 1996, the Institute ofApplied Ecology demonstrated in a phase-out scenario that there would only be atemporary increase in emissions if nuclearwere phased out completely, but thatincrease would quickly be compensated ifpower production facilities are completelyrevamped. Indeed, even if all of Germany’snuclear plants were switched off within a

year, four years later overall carbon emis-sions would be back at their original level61

provided that Germany implements anenergy policy focusing on greater efficiencyand renewables.62

Phasing out nuclear power plants wouldtherefore speed up the transition to theSolar Age. And there would be anotherbenefit – the risk of nuclear energy would bedone away with without increasing thegreenhouse effect.

Nuclear energy is a dying branch of powergeneration. Over the past 15 years, moreplants have been taken off-line than havebeen connected. And that trend willpresumably continue in years to come. Onliberalized energy markets, power providerscan hardly be expected to be interested inbuilding nuclear plants for economicreasons. Such plants are simply too expen-sive up front and take too long to complete.On closer inspection, it turns out that largeenergy conglomerates actually do not wantto expand nuclear energy, but merely keepthe ones already in operation running –despite the considerable risks.

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Figure 11.19 Phasing out nuclear

Source: Öko-Institute, 1996, EUtech and Greenpeace: Klimaschutz: Plan B, 2007

While a quick phaseout of nuclear power would increase carbon emissions inthe short term, emissions would actually drop even faster than under thestatus quo over the mid to long term if an energy transition policy focusingon efficiency and renewables were pursued. A recent study conducted byEUtech and Greenpeace confirms these findings.

The results are taken from a study conducted by the Institute of AppliedEcology based on figures from 1996

CO2 emissions in millions of tons per year

–25%

The German government’sreduction target for 2005

1,000

900

800

700

600

500

400

300

200

100

0

1990

1992

1994

1996

1998

2000

2002

2004

2006

2008

2010

2012

2014

2016

2018

2020

TrendEnergy transition


11.20 Renewable energy hereand in the developingworld

In previous sections, we have focused on themain instruments and steps towards asustainable energy supply in Germany. Inplaces, we have also mentioned how impor-tant renewable energy can be forsustainable development in the developingworld.

As difficult as it has been for us to switch tosolar energy, it is even harder for developingcountries to switch to a sustainable energysupply in light of their far worse economicsituation.63

• Environmental protection does not play amajor role in these countries, which facemore urgent economic and social prob-lems, such as widespread poverty.

• Generally, no capital is available forinvestments in renewable energy andefficient technologies.

• There is a great lack of proper trainingfor a sustainable energy supply and toolittle expertise about how a sustainabilitystrategy can be turned into policy.

• For social reasons, energy is often subsi-dized, making renewable energy andefficiency technology unaffordable.

Despite these upfront obstacles, renewablesand energy efficiency are just as important inthese countries on the path to sustainableeconomic development.

Often, electricity from Solar Home Systems ischeaper in areas without grid access than itwould be to expand the grid (see 3.3 and3.4). In such cases, solar energy can quiteeasily improve standards of living for thepoorest of the poor at the same time as itmarks a major step towards sustainable

development. However, for psychologicaland economic reasons the success of renew-able energy in off-grid applications dependson the success of such applicationsconnected to the grid. Otherwise, renewableenergy will be stigmatized as a ‘technologyfor the poor’, preventing it from being usedeverywhere and becoming a crucial part ofenergy policy. An economically feasible strat-egy that creates jobs and opens up newindustrial sectors will only be possible ifrenewables are used on a large scale.

The widespread use of renewable energy inthe developing world is still not possiblebecause of the relatively high cost. It istherefore the obligation of industrializedcountries to reduce the cost of renewables inorder to make these technologies moreinteresting for the developing world.Furthermore, the experience gained inGermany and elsewhere with certain policyinstruments can be passed on to these coun-tries.

This approach is successful, as a number ofinternational projects demonstrate. TheRenewable Energy Act is already used in anumber of countries as a sort of template,and some types of renewable energy – suchas wind turbines – are already competitivewithout any subsidies as their pricescontinue to drop and oil prices continue torise (see 6.6).

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Figure 11.20 Renewables for off-grid applications

Source: triolog, Frauenhöfer ISE, Solar-Fabrik AG


12.1 Everyone loves the sun

As we have seen in previous chapters,renewables have only been able to conquera limited number of market segments, suchas solar heating for outdoor swimming pools(2.1) and multi-family dwellings, windpower in good locations, and Solar HomeSystems in the Third World (3.3). In othercases, proper policies (especially feed-intariffs) and changes in the general businessenvironment are needed to attain therequired growth levels. Wherever solarenergy is not yet competitive with otherenergy sources, it pays to conduct marketingcampaigns to raise awareness about theadditional environmental benefits ofexpanding renewables.

In this chapter, we present a number ofexamples. All of these successful marketingstrategies share one thing: a focus on thewidespread acceptance of solar energy andother types of renewable energy in a largemajority of the population. Back in the1970s, German politicians responded to thefirst oil crisis by arguing that we shouldmove away from our dependence on asingle energy source to have a broader mixconsisting of nuclear energy, coal, oil, gas,and renewables. Today, there is almost nosupport for nuclear energy, and fossil energyhardly plays a role in the forecasts for futureenergy supply. A majority of the populationwants to have their future energy come fromrenewables (see Figure 12.1).1 A greatmajority (74 per cent) even wants thecurrent support in Germany to be main-tained.2 A slightly smaller share of thepopulation, but nonetheless a clear majority(around 70 per cent), is willing to pay morefor electricity from renewables.3

Along with the public’s willingness to paymore, the positive image that renewableshave is clearly utilized in the examplesdiscussed in the rest of this chapter. Forinstance, people are clearly willing to:

• Pay more for green power, just as theyare willing to pay more for organic food(see ‘Green electricity’ 12.2, Solarbrokers 12.4).

• Invest in solar, wind and biomass plants(see ‘Community systems’, 12.3).

Combinations of completely different prod-ucts – such as shares in solar arrays andseason tickets to football matches – havealso already proven successful on the market(see 12.9).

The examples discussed are not exhaustive.Rather, they are intended to serve as startingpoints, possibly even leading to new market-ing ideas. In fact, we would be interested asthe authors to hear about your new ideas.

12

12 Good Marketing – Successful Projects


207

Good Marketing – Successful Projects

12

Figure 12.1 Public support for renewables

Source: Forsa, 2005

What source of energy should play a major role in Germany’spower supply over the next 20 to 30 years?

Answers in per cent*

100

80

60

40

20

0

*Percentages add up to more than 100 per cent because multiple answerswere possible

Sola

r en

erg

y

Win

d p

ow

er

Hyd

rop

ow

er

Geo

ther

mal

Bio

mas

s

Nat

ura

l gas

Oil

Nu

clea

r p

ow

er

Co

al


12.2 ‘Green electricity’

On 29 April 1998, Germany’s new EnergyIndustry Act went into force. Since then, allpower customers have been able to choosetheir power provider and type of electricity.Companies responded quickly by starting tooffer ‘green electricity’. Some even believethat the liberalization of the power market isa first step towards the energy transitiondescribed by the Institute of AppliedEcology; they believe that consumers arevoting with their feet by moving away fromnuclear energy and towards renewables attheir own wall sockets.

What are we to make of the concept of‘green electricity’? How does it differ fromgood old electricity? First, we must keep inmind that the electricity itself is exactly thesame in both cases. The only difference ishow the power is produced. So what are themost important things that make electricity‘green’?4

• To begin with, ‘green electricity’ shouldcome from renewables to the greatestextent possible. Other types of technolo-gies, however, such as distributedcogeneration, also considerably reducethe environmental impact and can be alegitimate part of a green electricitypackage.

• More importantly, the production facili-ties that make this ‘green electricity’should be newly installed. If old equip-ment is used, then consumers are merelybeing asked to pay more for systems thatwere already up and running anyway. Ifsubscribers of green power do not forcecompanies to install additional systems,the overall environmental impact ofpower generation does not improve. Theonly thing that does improve is thepower provider’s bottom line; after all,

the same electricity was already sold at alower price to the general customerbase.

• Because the product that green powercustomers purchase is identical tonormal electricity, customers must becertain that the qualifications for thislabel are properly enforced. In otherwords, we need reliable certification andlabels for ‘green electricity’.

• Furthermore, we have to make certainthat the amount of green power solddoes not exceed the amount generated;such review should be a part of certifica-tion.

• Other criteria also offered in the ‘greenelectricity’ packages, such as ‘full service’and simultaneous generation,5 are,however, not as important.

‘Green electricity’ is a matter of trust.Generally, providers want to show that theyare a part of a ‘sustainable energy sector’.But customers nonetheless have to take acloser look at what they are supporting.Some companies that offer green electricityactually originally filed suit against the Feed-in Act. Others continue to support nuclearpower strongly. In addition, some municipalpower providers still do their best to preventcogeneration units from being connected tothe local grid. Such companies are merelyoffering ‘green electricity’ to improve theirimage; otherwise, these companies areclearly pursuing business practices thatdamage the climate.

In other words, even a product label canonly cover certain aspects of a company as awhole.6

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Figure 12.2 Green power from utilities

Source: The authors

Nuclear plantsGas turbinesCoal plants

HydropowerWind

Solar powerCogeneration

Grid

Consumption


12.3 Not everyone owns theroof over their head –community solar arrays

Financing is not the only obstacle towardsrenewables. For instance, a lot of peoplehave the money but don’t have a good roof:

• Roughly half of Germans do not owntheir own homes.

• Just under 20 per cent of the rest live inapartments with shared roof space, andPV arrays generally cannot be installedon such roofs without the consent of allthe owners, which often proves to be anobstacle to investments in practice.

To make it easier for such people to startusing solar and tap unused potential, theidea of community solar arrays was devel-oped. Essentially, private investors buyshares of arrays set up in good locations.

There are a number of benefits:

• The community arrays are set up inoptimal sites, which insures good solaryield. There is no lack of space on indus-try roofs and public buildings.

• Because of the system size, the specificcosts are low.

• By breaking down the cost of a largearray into a large number of shares,people with average incomes can alsoget involved.

Three groups/partners have to cometogether in a community solar project:7

The owners

• pay for the investment and• receive compensation (minus trusteeship

and overhead).

The solar firm

• plans and installs the array and• provides service and maintenance.

The management

• draws up the installation and mainte-nance contracts on behalf of the owners,

• oversees installation until the final billhas been paid,

• applies for public funding and• manages provisions and allocates

income.

A number of such community projects havealso come together for wind power,hydropower and biomass.

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Figure 12.3 Community projects for solar power

Source: The authors

Organizing community solar power projects

Owners– pay for investments– receive compensation (minus

overhead)

Trustees– apply for funding– sign installation and maintenance

contracts– follow-up project and pay

purchase price– handle bookkeeping for revenue– manage provisions

Solar firm– plans project and installs array– performs maintenance and

operation

Benefits of community-owned systems– optional sites provide good returns– lower costs from larger systems– investment shares make projects affordable


12.4 Solar brokers

Back in 1995, the Municipal Utility of Zürichconducted a representative survey of 3500randomly selected customers. Seven percent of them stated that they would beinterested in paying more for solar power. Toserve that demand, a solar power exchangewas created in Zürich. At the exchange, themunicipal utility serves as a broker betweensupply and demand, i.e. between solarpower producers and buyers of solar power(both private homes and businesses). Toensure that the cheapest solar power istraded, the municipal utility issued a requestfor proposals for solar power. The utility thenchose the 12 least expensive providers/ofsolar arrays from the 21 bids tendered. Theaverage solar price from these bids was 1.2Swiss francs per kilowatt-hour. The utilitythen signed a power purchase agreementwith the solar power producers for 20 years.If demand for solar power were to dropduring this timeframe, the extra costs wereto be passed on to all of the utility’scustomers.

At the beginning of 1997, the solar powerwas then offered to these customers at cost— at the price of 1.2 Swiss francs per kilo-watt-hour. Demand exceeded expectations.The utility was not able to provide enoughsolar power. By the end of 1997, the supplyof solar power was being rationed to keepup with demand. As a result, the utilitystarted another round of requests forproposals to cover demand. In this secondround, the price of a kilowatt-hour of solarpower fell below 1 Swiss franc, bringingdown the overall cost to 1.11 Swiss francsper kilowatt-hour starting in 1999.

In September 1999, the utility had 5,690customers purchasing just under800,000kWh of solar power under contract.A total of 33 arrays with a collective outputof 1.1MW supplied the solar power. By thesummer of 2003, that figure had grown to68 arrays with an output of 2.3MW. Thissuccessful model was copied in other partsof Switzerland and abroad. It quicklybecame a role model at more than tenpower providers in Switzerland, and some ofthe projects were very successful.8

The Municipal Utility of Zürich was pleasedthat other firms were copying its SolarPower Exchange. But the firm alsocomplained that a number of the copieswere not close enough to the original:‘When other power providers sell watereddown products under the name Solar PowerExchange – which we unfortunately cannotpatent – they are misleading customers anddamaging not only their own image, butalso the idea itself. Unlike our stockexchange, solar customers on some othersimilar exchanges are simply financing solararrays that had already been built.’9

By 2010, the price of a kilowatt-hour of solarpower on the Zürich Solar Power Exchangehad fallen to 0.70 Swiss francs (withoutVAT).10

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213


12

Figure 12.4 Solar brokers: The example of Zürich

Source: Elektrizitätswerke Zürich (CH)


12.5 Service brings in newcustomers for all-in-onepackages

The installation of a solar thermal array isquite a task for homeowners. You have toget information, compare technicalconcepts, choose one, see what it wouldcost, compare the offers, pick someone todo the job, find out about what publicfunding is available, apply for it and thenkeep an eye on your system for decades tomake sure it is properly functioning – quite alot of tasks these days, when people do nothave a lot of time. Here, municipal utilitiescould step in and perform all of this as aservice to win over some new solar friends.

For instance, utilities can offer theircustomers turnkey solar arrays at a fixedprice. The price would include consultingservices, planning and applications for publicfunding. To the extent necessary, the utilitycould even work with local contractors. Theutilities could issue calls for tenders and havequalified contractors perform the work. Inthis way, the utility would do all of the workfor the investor up to the point where thearray goes into operation. Homeownerswould then pay a fixed price for an arraythat will provide hot water practically forfree for the next 20 years.11

In Germany, the municipal utility of Ettlingen(40,000 inhabitants) offers such an all-in-one service to both homeowners andbusinesses. Launched in 1996, theprogramme installed more than 100 solarthermal systems within the first two years, afigure that had risen to more than 400 bythe end of 2005. By 2003, the utility hadgenerated some €2.6 million of additionalorders for local contractors. Customers arethe first to benefit, but satisfied customersare also good for the utility because they donot move to the competition. In this respect,promoting solar energy is a good idea forthe utility.

The utility also offers another service forrenewable heat. Even though it is a naturalgas supplier itself, the municipal utility ofEttlingen also supplies its customers withwood pellets of only the best quality toensure smooth, low-emission operation –and certainly also to retain customers.

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12

Figure 12.5 Service wins over new customers: All-in-one packages

Source: The authors

Energy service firms

Provide support whenapplying for funding

Inspect workperformed by

installers

Put system intooperation Warranties

Delivery andinstallation ofcomplete array

Issue of requests forproposals and signing

of contracts

Consulting


12.6 Investing in climateprotection

When we talk about climate protection, weare not only talking about solar energy, butabout energy in general. While it is nice toimagine how all buildings will one day benefitfrom solar energy, a sustainable energy supplywill not be possible unless we reduce ourexcessive energy consumption dramatically.

The ECO-Watt project shows how energyconservation and solar energy work together.

Initiated by the Institute of Applied Ecologyand developed in cooperation with theFraunhöfer Institute for Solar Energy Systems(ISE), the project aimed to prove that energyconservation already pays for itself a lot of thetime. The idea was to exploit the conservationpotential in a school in order to finance theinstallation of a solar array from the energysavings. In July 1999, the first ‘negawattplant’ in Germany financed by means ofcommunity contracting went into business.

In June 1998, the project began looking forinvestors via two local firms: Freiburg’sEnergy and Solar Agency (Fesa) and ECO-Watt. By November 1998, a total of€245,000 had been collected. Some 100investors, including a number of parents andteachers from the Staudinger School, werepart of the project.

Some €280,000 was invested in new light-ing, controlled circulation pumps, moreefficient heating and ventilation controls,two solar arrays, modern demand manage-ment and water conservation. The work wasdone by a local contractor in cooperationwith a subsidiary of ECO-Watt dedicated tothis project. The city of Freiburg paid thefirm the difference between the old and thenew energy costs for a period of eight years.

Eight years after the project started, it canclearly be considered a success. Some 1.5million kilowatt-hours of electricity, 5.5million kilowatt-hours of heat and 77 millionlitres of water were saved. Investors werenot the only ones to benefit from thesavings; the school also received €79,000from the energy savings. Investors had a 6per cent return on their investments.12

About 2650 tons of CO2 was avoided overthe contract term. This means someone whoinvested €5,000 in the project saved 53 tonsof CO2 over the eight years. This roughlyequals the average CO2 emissions accountedfor by a German citizen over a five-yearperiod. There are other positive environmen-tal impacts as well. The efficient fluorescenttubes in the new lighting contain 90 per centless mercury than their predecessors. Also,the same level of illumination is nowprovided by a smaller number of lights thatuse tubes with longer service lives, reducingthe number of tubes that have to be replacedeach year by more than 75 per cent – a majorimprovement for the school caretakers.13

Along with the technical planning, teachersand the parents/teachers association wereinvolved in the project. After all, one of theproject’s goals was not only to reduce energyconsumption, but also to make people awareof how they waste energy so that the new,efficient technology would be furtherbolstered by improved consumption patterns.

The project shows that climate protectiondoes not have to be expensive; on thecontrary, it already pays for itself in manycases. Solar thermal energy was used, aswas, to a lesser extent, photovoltaics. Profitmaximization was not the main goal –investing in a sustainable energy future was.And that goal can only be reached whenenergy conservation is combined with solarenergy.

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12

Figure 12.6 Climate protection as a good investment

Source: The authors

The ECO-Watt project at the Staudinger School

– Investors– silent partners (parents at the

school, citizens, etc.)– equity capital from ECO-Watt

– ROI up to 6 percent

– Principal repaidin eight years

– ECO-Wattinvest in energy / waterconservation and solar energysystems for the school

– Energy savingsThe city pays ECO-Watt the differencebetween old and new utility bills foreight years.

– Benefitsthe school also benefitsfrom the savings

– Investment capital


12.7 Utilizing new leeway

The liberalization of the power market (see1.10) has also brought about some positivechanges. For instance, compensation forpower from solar arrays and small cogenera-tion units (up to 50kW) has beenconsiderably improved.

In light of these changes, the ECO-Wattproject described in section 12.6 was furtherdeveloped. In cooperation with Ö-Quadrat,the Wuppertal Institute came up with aconcept for schools called the 100,000WSolar Initiative.14

The basic idea behind this concept is toinstall 50W of solar power per pupil andsave 50W in lighting demand per pupil at aselect group of schools in the German stateof North Rhine Westphalia. Overall, 100W ofconventional power would then be offsetper pupil. A school with around 1000 pupilswould then represent a 100,000W solarnegawatt plant.

Furthermore, the project managed to getutility companies onboard. In the renovationof the Aggertal School, the renovation ofthe lighting system, the installation of a43kW solar array, hydraulic support forheating circuits15 and pump renovation wasfinanced with investments from communitycontracting. The power supply for theAggertal school comes from a 50kW cogen-eration unit, which also supplies a schoolwith heat at a price competitive with naturalgas.

Overall, the school currently produces farmore electricity than it consumes. Theenergy conservation measures brought theoriginal annual power consumption of120,000kWh down to around 65,000kWh.The solar array produces some 35,000kWhper year; the cogeneration unit, an addi-tional 230,000kWh. As a result, the schoolnow emits 70 per cent less carbon than itdid before renovation. In a second project atthe Willibrord School in Emmerich, carbonemissions were even reduced by 85 percent.16

In the summer of 2003, these two projectswere featured in the Future Energy initiativein the state of North Rhine Westphaliabecause of the example they set.

The investors, most of whom are parentsand teachers at the school, get more than 6per cent return on their investments over aterm of 20 years. In the meantime, 4 schoolprojects are ongoing under the solar&savelabel.17

Germany’s Renewable Energy Act was onething that made these projects possible;another thing was the CogenerationModernization Act. In addition, ecologicaltaxation reform has increased the price ofelectricity, but cogeneration units areexempt from the tax on gas, providing abetter return on investments.

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12

Figure 12.7 Renovation of the Willibrord School as a community project: Carbon emissionswere reduced by 85 per cent in 2005

Source: The authors

Tons CO2/a

Before renovation

After renovation

100%

14%

1,000

800

600

400

200

0

–200

–400Heating

(gas)Heating/cogen (gas)

Powerconsumption

Carboncredits for

power fromcogen

Carboncredits for

photovoltaicpower

Sum


12.8 Using new technologies

Worldwide, some 1.6 million people dowithout electric light today – more than inthe 1880s, when Thomas Edison inventedlightbulbs.18 These people make do with oillamps and candles to light their homes, anoption that is not only expensive, but alsodangerous to the environment andhazardous to people’s health.

• Oil lamps give off a lot of soot, whichbuilds up indoors and can lead to respi-ratory diseases and cancer. Furthermore,a low level of light makes indoor workless efficient and impairs vision over thelong term.

• Because oil lamps give off very little light,the carbon emissions of this lightingtechnology are relatively high – roughly20 times higher than conventional light-ing with electricity from coal and oilplants. If lighting instead comes fromsolar power, the CO2 emissions from oillamps can be reduced by some 80kg peryear.

Electric lighting therefore clearly reduces theenvironmental impact even as it improvesstandards of living. In regions with no gridaccess, solar power and compact fluorescentlighting (‘Solar Home Systems’, see 3.3) arecurrently the least expensive way of provid-ing lighting to households. Nonetheless, thehigh cost keeps them from becoming morewidespread.

Recently, white light emitting diodes (LEDs)were developed and will soon further reducethe cost of solar lighting considerably, whichwill make solar lighting available to morepeople. Because white LEDs make do withso little electricity, both the solar panel andthe battery can be smaller, reducing theoverall system cost. In addition, LEDs areharder to break and have a service life of upto around 100,000 hours, roughly 10 timeslonger than compact fluorescent bulbs and100 times longer than conventional lightbulbs.

The cost of efficient solar LED lighting with afocusing lens is already clearly lower thanthe cost of conventional lighting, such as oillanterns, candles and battery-operatedtorches.19 Efficient technology and solarenergy can therefore bring light to remoteregions of the world with funding coming inthe form of microcredit.

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Figure 12.8 Solar lamps replace oil lamps: Benefits for people, environment and climate

Source: The authors

Good light improveslearning environment

Climate gases areavoided

No toxic emissions

No risk of fire

Opportunities for services and small

businesses


Preface

1 Die Zeit, 2 November 2006, p26.2 German Solar Industry Association (2006)

Statistical Figures of the German SolarIndustry, June 2006.

3 Renewables Global Status Report, 2009, p9.4 Neue Energie, March 2010, p94.5 Die Zeit, 2 November 2006, p26.

Chapter 1

1 Handelsblatt, 13 October 2006.2 BP Statistical Review of World Energy, June

2006.3 For example, US oil specialist Professor

Kenneth P. Deffeyes declared 24 November2005 to be World Peak Oil Day, the day whenglobal oil production peaked. Taken fromEnergiedepesche, March 2006, p.4. See alsowww.peak-oil.de and Heinberg, R. (2004) TheParty’s Over: Oil, War and the Fate ofIndustrial Societies, New Society Publishers,Canada.

4 BP Statistical Review of World Energy, June2006.

5 Statistisches Jahrbuch für die BundesrepublikDeutschland 2006, p467.

6 For example, the European Commission andthe International Energy Agency (IEA) warnedtheir member states about the unreliability ofRussian energy giant Gasprom as a reaction tothreats made by the firm’s CEO. FinancialTimes, 20 April 2006.

7 This list is not intended to be exhaustive. Seealso Institute of Applied Ecology (2005) RisikoKernenergie: Es gibt Alternativen!, Institute ofApplied Ecology, Freiburg.

8 See ‘Geisterflug auf der Geisterbahn’, DieZeit, 10 August 2006.

9 Germany is by no means alone in Europe indoing so. Denmark, Greece, Ireland, Italy,Luxembourg, Austria and Portugal haverenounced nuclear power. In 1984, Swedenresolved to phase out nuclear, and Spainimplemented a moratorium to prevent theconstruction of additional nuclear plants inthe same year.

10 Institute of Applied Ecology (2005) Risiko

Kernenergie: Es gibt Alternativen!11 The Institute of Applied Ecology puts the

figure ‘at 40 years, whereas Greenpeace saysthe figure could reach 65 years. Institute ofApplied Ecology (2005) Risiko Kernenergie: Esgibt Alternativen!; www.greenpeace.de/themen/atomkraft (February 2006).

12 Rechsteiner, R. (2003) Grün Gewinnt: DieLetzte Ölkrise and Danach, Orell Füssli, Zürich,especially pp39–45.

13 Schneider, M. (2005) The Status of NuclearPower in the World, presentation in Brussels,7 November 2005.

14 Bernward Janzing in Badische Zeitung, 10January 2007.

15 Arbeitsgemeinschaft Energiebilanzen, January2006, www.ag-energiebilanzen.de.

16 Bundesanstalt für Geowissenschaften andRohstoffe (2006) Reserven, Ressourcen andVerfügbarkeit von Energierohstoffen 2005,Hannover. Nonrenewable energy is catego-rized into two groups: reserves and resources.The reserves are proven and affordable withcurrent technology. The volume thereforedepends on current energy prices. Resourceshave either been proven but are currently notaffordable, or they have not been proven butare geologically probable.

17 Geothermal is an exception (see 7.5–7.7). Itcan round off solar power.

18 In addition, land and water do not heat up atthe same rate, which also causes air turbu-lence.

19 Scheer, H. (1993) Sonnenstrategie: Politikohne Alternative, Munich, p109.

20 Lehmann, H. and Reetz, T. (1995)Zukunftsenergien: Strategien einer neuenEnergiepolitik, Birkhäuser Verlag, Berlin.

21 Krause, F., et al. (1980) Energiewende:Wachstum and Wohlstand ohne Erdöl andUran, Frankfurt.

22 Deutscher Bundestag (1990) Schutz der Erde:Eine Bestandsaufnahme mit Vorschlägen zueiner neuen Energiepolitik, Bonn, especiallyvol 2, p158ff.

23 von Weizsäcker, E., Lovins, A. B. and Lovins, L.H. (1998) Factor Four: Doubling Wealth,Halving Resource Use – The New Report tothe Club of Rome, Earthscan, London.

24 Nitsch, J. (2007) Study commissioned by

222

Notes


German Ministry for Environment, NatureConservation and Nuclear Safety (BMU),February 2007.

25 Umweltbundesamt: Wie private Haushalte dieUmwelt nutzen – höherer Energieverbrauchtrotz Effizienzsteigerungen, Hintergrund-papier, November 2006

26 This example was used by Stryi-Hipp, G. inSonnenenergie frei Haus - Solarthermie andPhotovoltaik nutzen, presentation on 22January 1997, Bonn.

27 Irrek, W. and Thomas, S. (2006) Der EnergieSparFonds für Deutschland, Düsseldorf.

28 The amount of heat that dissipates frompower plant cooling towers is greater thanthe heat used to keep apartments and officeswarm in Germany.

29 The Verband der Elektrizitätswirtschaft(VDEW) wrote in their annual report of 1996that they had had a survey conducted, whichfound that the 50 largest power providers hadfaced the challenge of businesses wanting togenerate their own power in nearly 2000cases from 1994–1996. With flexible pricing,the power providers were able to persuadethe businesses not to generate their ownpower in most cases.

30 Bundesverband Kraft-Wärme-Kopplung,Stellungnahme zur Novellierung des Kraft-Wärme-Kopplung-Gesetzes, September2006.

31 Traube, K. (2005) Potentiale der KWK.Bundesverband der Kraft-Wärme-Kopplunge.V., January 2005.

32 In least-cost planning, the cost of implement-ing energy conservation is compared to thecost of expanding power plant capacity andthe grid. The goal is to choose the cheaperoption.

33 The ecological taxation reform and theRenewable Energy Act have brought about alot of change here.

34 Around 38 per cent in 2006.35 Süddeutsche Zeitung, 7 September 2006.36 Main-Spitze, 5 October 2006.37 A private household in Freiburg with an

annual consumption of 3500kWh paid€778.55 if power came from the local utility(Badenova); the cheapest offer in Germanywould have been €570 (Flexstrom, 3600-Paket). The green of power offers fromLichtblick and EWS-Schönau (Watt ihr spart)were also cheaper than the local utility at€730.39 and €748, respectively. www.stro-mauskunft.de

38 An energy service provider not only sellspower and gas, but also works to make surethat these energy sources are used as effi-ciently as possible, for instance by financingpower conservation consulting services andcampaigns for efficient power consumption.

39 See Hennicke and Seifried (1996) DasEinsparkraftwerk, Berlin, Basel, Boston.

40 Wirtschaftsminister Riehl quoted in Taz, 5October 2006.

41 On the one hand, coal and heating oil, whichhave been exempt up to now, should betaxed, but the number of exemptions shouldalso be reduced (kerosene, net-metering,refineries, agriculture, etc.). To prevent furtherredistribution effects, the tax rate for theproduction sector should be raised slightlymore than the rate for private consumers.

42 Irrek, W. and Thomas, S. (2006) DerEnergieSparFonds für Deutschland,Düsseldorf

43 For example in England, Denmark and somestates in the US.

44 See Wuppertal Institute (2001)Energieversorger auf dem Prüfstand,Wuppertal.

45 Energy conservation contracting is a contrac-tual agreement between a firm (contractor)and a building owner. The contractor makesthe investments and performs the workneeded to conserve energy in the building.The building owner then pays the contractorthe difference between the old and the newenergy costs to cover the contractor’sexpenses. The building owner does not haveto invest, does not run any risk, and nonethe-less benefits from the success of renovations.

46 Part of a sustainable energy sector is thatresources are not consumed faster than theycan ‘grow back’.

47 Just because conservation measures wouldpay for themselves does not mean that theyare actually implemented.

48 May, H. (2006) ‘Kostensenker vom Dienst’,Neue Energie, October 2006, p14.

49 PROKON (2006) Der Wind hat sich gedreht,Sonderveröffentlichung, Itzehoe.

50 Joint press release of UBA and BMU on 17October 2006 on the launch of the newCentre of Competence for Climate Impactand Adjustments.

223

Notes


Chapter 2

1 For further details, see Schüle, R., Ufheil, M.and Neumann, C. (1997) ThermischeSolaranlagen: Marktübersicht, Ökobuch Verlag,Staufen bei Freiburg, p. 41ff. See also DeutscheGesellschaft für Sonnenenergie (2006),Nutzerinformation Solarthermie, Munich.

2 This calculation is based on a heating oil priceof 6 eurocents per kilowatt-hour (roughly 60eurocents per litre); in addition, it is assumedthat the price of heating oil will increase by 3per cent per year. Because prices rose from1998–2006 by a much higher average of 13per cent, no financing costs were calculatedfor. Under these assumptions, the savings inthe heating oil costs amount to €4800 over20 years. If the system replaces an electricwater heater, the savings amount to €10,200over 20 years; Bundesverband Solarwirtschaft(2006) Zeitung für Solarwärme.

3 The share of solar arrays used for spaceheating rose to around 45 per cent in 2006 asa share of newly installed systems;Bundesverband Solarwirtschaft (2006)Zeitung für Solarwärme.

4 Thermochemical heat storage opens up newperspectives. Five times as much heat can bestored as in a conventional hot water tank ofthe same volume. Here, reversible chemicalreactions take place; for instance, a solid canabsorb a fluid. In addition to the greaterenergy density, one major benefit is that theheat is stored for a long time practicallywithout any losses. For a presentation of suchstorage projects, see ThermochemischeSpeicher, BINE-Projektinfo 2/01.

5 R. Kübler and N.Fisch (1998) ‘Energiekonzeptfür die Zukunft. Neckarsulm Amorbach –solare Nahwärme in der 2. Generation’,Solarenergie vol 1, pp36–37; Berner, J. (2001)‘Sommersonne für den Winter: Langzeit-Wärmespeicher haben ihre Tauglichkeitbewiesen’, Sonnenenergie Nov. 2001,pp16–19; see Rentzing, S. (2006) ‘CooleSonne’, Neue Energie, vol 4, pp38–43.

6 Rentzing, S. (2006) ‘Coole Sonne’, NeueEnergie, vol 4, pp38–43.

7 For details on the process, see Hindenburg,C., et al (1999) ‘Kühlen mit Luft’,Sonnenenergie, vol 1, pp 39–41.

8 The dew point is the temperature at whichthe gas part of a gas/vapour mixture (air withwater vapour here) is completely saturated.

The water vapour condenses when thetemperature drops.

9 Hindenburg, C., et al (1999) ‘Kühlen mit Luft’,Sonnenenergie, vol 1, pp39–41.

10 Rentzing, S. (2006) ‘Coole Sonne’, NeueEnergie, vol 4, pp38–43.

11 W. Mühlbauer and A. Esper (1997) ‘SolareTrocknung’, Sonnenenergie vol 6, pp35–37;Köpke, R. (2002) ‘High tech by low cost’,Neue Energie, vol 2, pp38–41.

12 In Europe north of the Alps, sludge can beaffordably desiccated with solar energy inlarge air collectors that resemble green-houses. Bux, M. (2002) ‘SolareKlärschlammtrocknung – eineernstzunehmende Option?’, Baden-Württembergische Gemeindezeitung, vol 4,pp145–147.

13 Brake, M. (2006) ‘Luftkollektoren heizenWohnhäuser. Warme Luft von der Sonne’,Sonnenenergie, September 2006, pp30–36.

14 BUND (2005) Vorbildliche Energieprojekte vonKreisen and Kommunen in Hessen, Frankfurt.

15 ‘Start für Parabolrinnenkraftwerk’,Solarthemen, 8 June 2006, p4; Keller, S.(2006) ‘Es geht voran’, Sonnenenergie, July2006, pp32–37; Pitz-Paal, R. (2006) SolareKraftwerke, presentation at the Quo vadisSolarenergie symposium, Freiburg, 15September 2006.

16 REN21: Renewable Global Status Report,2009 Update, www.ren21.de. See alsonreldev.nrel.gov/csp/solarpaces.

17 www.desertec.org18 In July 2006, construction of a 1.5MW

demonstration unit was begun in Jülich,Germany; Badische Zeitung, 5 July 2006.

19 Klaiß, H. and Staiß, F. (1992) SolarthermischeKraftwerke für den Mittelmeerraum,Springer-Verlag, Heidelberg; Pitz-Paal, R.(2006) Solare Kraftwerke, presentation at theQuo vadis Solarenergie symposium, Freiburg,15 September 2006.

Chapter 3

1 See Leuchtner, J. and Preiser, K. (1994)Photovoltaik-Anlagen, Marktübersicht1994/1995, Institute of Applied Ecology,Freiburg, p13ff, and current reports in Photon(www.photon.de).

2 Leuchtner, J. and Preiser, K. (1994)Photovoltaik-Anlagen, Marktübersicht 94/95,Institute of Applied Ecology, Freiburg, p56f;

224



Weithöner, H. (2003) ‘Aus alten Zellen neuemachen: Deutsche Solar steigt in Freiberg indas PVRecycling ein’, Sonnenenergie, March2003, pp41–43.

3 Kilowatts-peak describes the peak output of aphotovoltaic array; i.e. the electricity gener-ated under full sunlight.

4 Stryi-Hipp, G. (Bundesverband Solarwirtschafte.V.) (2006) ‘EEG-Novelle und regnerativesWärmegesetz – Chancen und Heraus-forderungen für die Deutsche Solarindustry’,presentation, July 2006.

5 In sparsely populated rural areas, a gridconnection can cost thousands of US dollars.Gabler, H. and Preiser, K. (1999) ‘Photovoltaik– ein Baustein zur nachhaltigen Entwicklungnetzferner Regionen’, ForschungsverbundSonnenenergie (c/o DLR), Nachhaltigkeit andEnergie, Themen 1998/1999, Cologne,pp28–31.

6 REN21: Renewables 2005: Global StatusReport, Washington 2005, p32f.

7 Schmela,M. (1999) ‘Kleinvieh macht auchMist: Wo sich in unseren Breiten Solarstrom-Anlagen rechnen’, PHOTON, vol 2, pp44–51.

8 International Solar Energy Society (2002)Sustainable Energy Policy Concepts (SEPCo),study conducted on behalf of the GermanMinistry of the Environment, NatureConservation and Reactor Security, Freiburg.For further information, seewww.ises.org/shortcut.nsf/to/ICNFINAL.

9 Microgrids provide power to a village notconnected to the country’s power grid. Withinthe small grid, power can be generated fromfossil energy (such as a diesel engine), fromsolar energy, or by a combination of differenttechnologies.

10 Professor J. Luther, director of the FraunhöferInstitute for Solar Energy Systems until 2006,in an interview in Bild der Wissenschaft, vol 9,2006, pp96–99; BINE (2005) ‘Photovoltaik –Innovationen bei Solarzellen and Modulen’,Themen-Info, vol 3, Bonn.

11 One reason was a lack of solar silicon. In themeantime, this bottleneck has been resolved,partly by the opening of production plants forsolar silicon.

12 www.solarwirtschaft.de/medienvertreter/pressemeldungen/meldung.html?tx_ttnews[tt_news]=12944&tx_ttnews[backPid]=737&cHash=64a1a4abfd.

Chapter 4

1 See Steimer, G. and Lohbihler, I. (1998)Energiekonzepte für zukunftsfähigeNeubauten, Freiburg, pp9 and 11.

2 The stipulations in Germany’s EnergyConservation Ordinance (EnEV) cannot bedirectly compared to those of its predecessorbecause the new limit values applied toprimary energy consumption in a building. Inother words, they also take account the typeof fuel used and the efficiency of the heatingsystem. The previous ordinance only specifiedlimit values for heating energy demand.

3 Goetzberger, A. and Wittwer, V. (1986)Sonnenenergie, Stuttgart, p132ff.

4 The U-value of a building component indi-cates how much power (how many watts) islost over an area of 1m2 for every degree oftemperature (1K).

5 For examples, see www.solarbau.de,www.energie-projekte. de andwww.baunetz.de/infoline/solar.

6 Ebök (Tübingen) (1998) Energieeinsparungbei Neubausiedlungen durch privat- andöffentlich-rechtliche Verträge, Cologne.

7 Stadt Köln; Ministerium für Arbeit, Soziales...NRW: Planen mit der Sonne, Arbeitshilfen fürden Städtebau, Düsseldorf, Cologne 1998,pp12 and 48: The authors estimate 0.1 euro-cents per kilowatt-hour offset.

8 The example is taken from Ranft, F. and Haas-Arndt, D. (2004) Energieeffiziente Altbauten,Cologne, p122ff.

9 As of March 2007; for current information,see www.kfw.de.

10 Germany’s Energy Conservation Ordinance isnot based on heating demand, but rather setsa limit on primary energy consumption, whichalso takes account of how heat is generated.The installation of a solar thermal array or awood pellet stove can therefore help youreach the targets in Germany’s EnergyConservation Ordinance.

11 One factor in determining indoor comfort isthe surface temperature of walls. In poorlyinsulated buildings, people might feel coldeven though room temperature is highenough simply because the walls are cold.

12 Russ, C. et al (1996) Energetische Sanierungeiner Typenschule in Plattenbauweise unterVerwendung Transparenter Wärmedämmung(TWD), Fraunhöfer Institute for Solar EnergySystems, annual report, p18.

13 Switchable glazing is another option. If hydro-gen or oxygen is in between the panes ofglass, a thin layer of wolfram oxide will turn

225

Notes


either dark blue or transparent. Solarthemen,15 February 2001, p7.

14 Optimized multi-layer polycarbonate boardscan also be used for this purpose. BINE (1996)Transparente Wärmedämmung zurGebäudeheizung, profi info 1/96, Bonn.

15 Fachverband Transparente Wärmedämmunge.V., www.fvtwd.de.

16 Germany’s Energy Conservation Ordinancestipulates the limit on primary energyconsumption in buildings, not heating energyconsumption. Depending on the technologyused, 15kWh/m2*year (the passive housestandard) is equivalent to 20–40kWh/m2*year). A KfW-40 building (the requiredenergy standard for funding from Germany’sKfW Bank) is roughly equivalent to the passivehouse standard. BINE (2003), themeninfoII/03, Energieeffiziente Einfamilienhäuser mitKomfort, Bonn, p2.

17 Cost Efficient Passive Houses as EuropeanStandards (CEPHEUS). Under project numberBU/0127/97, this project was funded as partof the EU’s 5th Framework Programme andjointly conducted by Germany, France,Austria, Sweden and Switzerland.

18 Köpke, R. (1999) ‘The next generation: Passiv-Solar-Häuser setzen neue Maßstäbe beimEnergiesparen’, Neue Energie, vol 4,pp34–35.

19 Witt, J. and Leuchtner, J. (1999) Passivhäuser:Nischenprodukt oder Zukunftsmarkt? EineMarktpotentialstudie, presentation at the 3rdPassive House Conference 19–20 February1999, Bregenz.

20 IG Passivhaus press release on 6 August 2005;www.ig-passivhaus.de

21 BINE (1994), Energieautarkes Solarhaus,project number 18, Bonn 1994; FhG ISE(1992) Das energieautarke Solarhaus,Freiburg.

22 Today, this building is used by the FraunhöferInstitute for Solar Energy Systems as aresearch and institute building.

23 www.solarsiedlung.de. 24 This was the original concept, but the solar

thermal array was left out for reasons of cost.

Chapter 5

1 Fritsche of the Institute of Applied Ecologyputs the potential at 700PJ; Kaltschmitt puts itat 940PJ; Fritsche, U. (2004) Bioenergie,Nachwuchs für Deutschland, Institute of

Applied Ecology; ‘Biomasse – Potenziale inDeutschland’, Energiedepesche, vol 2, 2004,p18.

2 Some 4.4 million hectares (roughly 25 percent of our current agricultural land) ofenergy crops could provide 1200PJ, equiva-lent to around 9 per cent of primary energydemand. Fritsche, U. (2004) Bioenergie,Nachwuchs für Deutschland, Institute ofApplied Ecology. The FachagenturNachwachsende Rohstoffe (FNR) putsGermany’s biomass potential at 17.4 per centof the country’s primary energy consumption,a figure somewhat higher than Fritsche’s. FNR(2005) Basisdaten Bioenergie Deutschland,Gülzow.

3 Thomas, F. and Vögel, R. (1989) GuteArgumente: Ökologische Landwirtschaft,Beck’sche Verlagsbuchhandlung, Munich.

4 Fachverband Biogas e.V.5 Fachverband Biogas press release on 1

February 2007.6 FNR (2005), Basisdaten Biogas Deutschland,

Gülzow.7 Bensmann, M. (2007) ‘Freie Fahrt für

Fermenter’, Neue Energie, vol 1, pp52–55.Bensmann, M. (2005) ‘Mächtig Gas geben’,Neue Energie, vol 2, pp50–52.

8 Dederer estimates that a 180kW biogas unitwould need 77ha, at 13 tons of dry corn perhectare. For grass (8t TM/ha), a full 137hawould be needed. Dederer, M. (2005)Wirtschaftlichkeit von Biogasanlagen, presen-tation at the Biogas-Tagung der Akademie fürNatur- and Umweltschutz, Stuttgart, 19October 2005.

9 BMU (ed) (1999) Erneuerbare Energien andNachhaltige Entwicklung, Bonn, p56.

10 Böttger, G. (2010) ‘WachstumsmarktHolzenergie’, Sonnenenergie, January/February 2010, p26ff; Sowie, Neue Energie,vol 2, p74. At www.ECOTopTen.de, theInstitute of Applied Ecology presents especiallyenvironmentally friendly wood pellet heaters.

11 The Sunmachine creates heat with woodpellets, and a Stirling engine then convertspart of the heat into electricity, www.sunma-chine.de.

12 Forstabsatzfonds (2003) Holzenergie fürKommunen, 3rd edition, Bonn, p10.

13 Manufacturers report that 50–70 per cent ofpellet heaters are sold in combination withsolar thermal systems. Riedel, A. (2007) ‘Einstarkes Tandem’, Sonnenenergie, March2007, pp20–22.

226



14 KEA (1999) Faltblatt Klimaschutz durchHolzenergie, Karlsruhe.

15 Forstabsatzfonds (2003) Holzenergie fürKommunen, 3rd edition, Bonn, p88ff.

16 Neumann, H. (2006) ‘Feinstaub kratzt zuUnrecht am Holzimage’, Moderne Energie &Wohnen, vol 1, pp67–70; Bensmann, M.(2006) ‘Schreckgespenst Feinstaub’, NeueEnergie, vol 7, pp48–51.

17 Lewandowski, I. and Kaltschmitt, M. (1998)‘Voraussetzungen and Aspekte einer nach-haltigen Biomasseproduktion. Akademie fürNatur- and Umweltschutz Baden-Württemberg: Biomasse’, UmweltschonenderEnergie- and Wertstofflieferant der Zukunft ,vol 27, pp19–38.

18 Alt, F. (1999) Schilfgras statt Atom: NeueEnergie für eine friedliche Welt, Piper.

19 ‘Hier keimt die Power’, Neue Energie, vol 4,2006, pp47–49.

20 Schreiber, E. (2005) ‘Schweden gibt Biogas!’,Solarzeitalter, vol 3, pp25–26.

21 Chancen and Perspektiven flüssigerBioenergieträger in Deutschland, conferencereport of 14 February 2003, Böblingen.Newsletter March 2003 from the BiomasseInfo-Zentrums (BIZ), Stuttgart.

22 In 2005 some 1.3 million hectares of rapeseedwas planted in Germany, roughly 727,000haof which was used to produce biodiesel.Approximately half of that was on disusedland. Information based on personal contactwith Dr A. Weiske, Institut für Energetik andUmwelt, Leipzig, 9 November 2006.

23 FNR (2006) Biokraftstoffe, eine vergleichendeAnalyse, Gülzow, p20.

24 Since 1 August 2006, there has been a tax of9 eurocents per litre on biodiesel; it isexpected to rise to 45 eurocents per litre by2011. Pure vegetable oil has also been taxedsince 2008. The tax on biodiesel quicklyreduced sales, partly also as a result of loweroil prices. Germany’s Biofuels and RenewableFuels Association says that biodiesel was nolonger competitive starting at the beginningof 2007, and 25 per cent of Germany’sbiodiesel production capacity has alreadybeen decommissioned or stopped; pressrelease on 20 February 2007.

25 FNR (2005) Basisdaten Biokraftstoffe,Gülzow; Neue Energie, vol 2, 2006, p35.

26 German Bundestag 14/8711.27 FNR (2006) Biokraftstoffe, eine vergleichende

Analyse, Gülzow, p22.28 Das Bioethanol wird nicht direkt verkauft,

sondern dem Benzin beigemischt (bis 10%)oder zum Oktanverbesserer ETBE umgewan-delt und dann dem Benzin beigemischt.Bensmann, M. (2009) ‘Alkohol-Diät’, NeueEnergie, vol 5, p72ff.

29 Nitsch, M. and Giersdorf, J. (2006)Biokraftstoffe zwischen Euphorie and Skepsis– am Beispiel Brasilien, Solarzeitalter, vol 2,pp36–41; Sieg, K. (2005) ‘ZuckersüßeAlternative’, Neue Energie, vol 3, pp81–85.

30 Flex-fuel vehicles are necessary because moresugarcane than would be used to producesugar, thereby reducing the supply of ethanol,if sugar prices are high and oil prices are rela-tively low. In such cases, flex-fuel vehiclescould simply run on normal petrol.

31 Nitsch, M. and Giersdorf, J. (2005)Biotreibstoffe in Brasilien, FU Berlin,Volkswirtschaftliche Reihe 12/2005, BerlinJune 2005, p12.

32 Neue Energie, vol 5, 2009, p74.33 To attain the EU’s target of 5.75 per cent

biofuels as a share of the petrol market by2010, some 2.1 million tons of ethanol areneeded – roughly equivalent to 1 millionhectares of wheat fields or around 400,000haof sugarcane.

34 Moser, S. (2003) ‘Biomasse – Karriere einesSchmuddelkindep’, Bild der Wissenschaft, vol5, 2003, pp66–69.

35 FNR (2006) Biokraftstoffe: Eine vergleichendeAnalyse, Gülzow, p30.

36 For the time being, however, BTL productionrequires absolutely dry wood; processes basedon straw are not optimal. Bensmann M.(2006) ‘Den Königsweg finden’, NeueEnergie, vol 5, p63.

37 Bringezu, S. and Steger, S. (2005) Biofuels andCompetition for Global Land Use, conferencedocumentation from the Heinrich BöllFoundation: Bio im Tank, Berlin, p62ff.

38 EU-15 takes up some 35 million hectares ofland for food production outside of its ownterritory, roughly twice as much farmland as inall of Germany. That figure does not includeimports of animal feed. Overall, EU citizensuse roughly a sixth of the land they need forfood production outside of the EU. Bringezu,S. and Steger, S. (2005) Biofuels andCompetition for Global Land Use, pp5 and 67.

39 ‘If the world were to adopt such consumptionand supply patterns (including the 60 Mtoebiofuel equivalent), there would no longer beany relevant amount of natural grassland,pampa or prairie. Outside of forests there

227

Notes


would be crop land intensively cultivated byploughing and fertilization – a green desertaround the globe. Certainly a theoreticalscenario. The question is to which extent itmay become reality.’ Bringezu, S. and Steger,S. (2005) Biofuels and Competition for GlobalLand Use, p69.

40 Klute, M. (2007) ‘Fremdwort Nachhaltigkeit’,iz3w, no 298, January/February 2007, p34;‘Biodiesel-Import in der Kritik’, Neue Energie,March 2006, p29.

41 For example, rotating crops provides ecologi-cal benefits and greater yields in Germany.Bensmann, M. (2004) ‘Im Kessel Buntes’,Neue Energie, vol 8, pp50–51.

42 Berger, T. U. (2005) Mobilität durchLebensenergie, conference documentation ofthe Heinrich Böll Foundation: Bio im Tank,Berlin, p5.

Chapter 6

1 ‘Bundesverband Windenergie’, SüddeutscheZeitung, 8 December 1998. In the past fewyears, the price of a kilowatt-hour of windpower has hardly dropped. Improved systemtechnology, however, allows slightly morepower to be generated per installed kilowatt.Erfahrungsbericht zum EEG, DeutscherBundestag 14/9807, pp10–15.

2 DLR, IFEU, Wuppertal Institute (2004) Ökolo-gisch optimierter Ausbau der Nutzungerneuerbarer Energien in Deutschland,Forschungsvorhaben im Auftrag desBundesministeriums für Umwelt, Naturschutzund Reaktorsicherheit, Stuttgart, Heidelberg,Wuppertal, p164f.

3 Süddeutsche Zeitung, 8 August 1997. 4 For example, Baden-Württemberg’s governor

Erwin Teufel attempted to prevent theconstruction of two wind turbines in August2003 on Schauinsland Mountain although theturbines had basically already been completedbased on a construction permit. (LandtagBaden-Württemberg, 13/2395)

5 We realize how little space wind turbinesneed when we compare that space to thearea required by other renewables. Forinstance, a modern wind turbine (1.8MW,1800 hours running at full capacity per year)generates some 3.2 GWh per year. To gener-ate the same amount of electricity,photovoltaics would need around 5.4ha, anarea roughly 200m by 270m, with 60 per cent

of the area being covered (1000kWh per10m2 of panels). If the power is generatedfrom biomass, roughly 200ha of energy cropswould be needed, roughly 40 times the areaof photovoltaics. This calculation does notinclude the energy input for corn, forinstance, but the share of heat generated isalso not included.

6 BMU (ed) (1999) Erneuerbare Energien andNachhaltige Entwicklung, Bonn, p22.

7 Weinhold, N. (2006) ‘Die Flaute im Kopf’,Neue Energie, vol 2, pp39–42.

8 In Denmark, this has already happened withthe resolution to phase out nuclear powerand the adoption of clear energy policy goals,such as volume targets for wind power.

9 www.wind-energie.de.10 BMU (ed) (1999) Erneuerbare Energien and

Nachhaltige Entwicklung, Bonn, p31.11 Abo-Wind, press release on 4 September

2002.12 Erneuerbare Energie vol 5, 2005, p40.13 Neue Energie, 2/2002, p. 2114 Exports of wind turbines are extremely impor-

tant for Denmark today. The country’s onlyexport item that brings in more revenue ispigs. Naturstrom-Magazin, vol 1, 2001. Butsince the law changed in Denmark in 2001,Danish manufacturers have only been able tosell a few turbines domestically. See NeueEnergie vol 4, 2003, p44.

15 Press release from the BMU, 16 May 2006.16 www.wwindea.org/home/index.php?option

=com_content&task=blogcategory&id=21&Itemid=43.

17 www.wind-energie.de.18 Press release from the BWE, 27 January 2010.19 The New York Times, 9 October 2006.20 Of course, economic viability also depends on

the rates paid for power from onshore andoffshore wind turbines.

21 Most of the systems are larger than 2MW,www.offshore-wind.de.

22 REN21 (2009) Renewables Global StatusReport, 2009 Update.

23 www.dena.de/f i leadmin/user_upload/Download/Dokumente/Projekte/ESD/netzs-tudie1/dena-grid_study_summary.pdf.

24 http:/ /www.dena.de/en/topics/energy-systems/projects/projekt/grid-study-ii.

25 Lönker, O. (2006) ‘Flaute fällt aus’, NeueEnergie, vol 3, pp42–45.

26 ‘Bundesverband Windenergie: Repowering –weriger ist mehr’, Hintergrundinformation.2005.

228



27 Press release from the BWE, 27 January 2010,www.wind-energie.de.

Chapter 7

1 For an overview of turbine technology andtypes of hydropower, see LandesinitiativeZukunftsenergien NRW, Wasserkraftnutzung,Düsseldorf, no date.

2 BP Statistical Review 2006,www.bp.com/statisticalreview; BMU (2006)Erneuerbare Energien in Zahlen, Berlin.

3 WWF Deutschland (2004) Wasserkraft –weltweit von hoher Bedeutung, Berlin;Köpke, R. (2004) ‘Auf ewig heiß’, NeueEnergie, vol 10, pp85–91.

4 Landesinitiative Zukunftsenergien NRW,Wasserkraftnutzung.

5 www.energiedienst.de.6 Verband der Deutschen Elektrizitätswirtschaft.7 Staiß, F. (ed) (2001) Jahrbuch Erneuerbare

Energien , Stiftung Energieforschung Baden-Württemberg, Bieberstein.

8 For instance, a small firm from Karlsruhe(Hydro-Watt) found a way to get old watermills to produce as much as 30 per cent morepower. The water mills used to run atconstant speed because the generatorrequired that speed for a connection to thegrid. But modern electronics allows the speedof water mills to be adjusted to the actualamount of water. A frequency converterensures that the frequency of the power soldto the grid is the right one; Neue Energie, vol5, 1999.

9 The Wikipedia list of the world’s largest powerplants now shows nine such plants with anoutput exceeding 5000MW, with four othersunder construction. www.wikipedia.de.

10 The great criticism of hydro plants has reducedthe amount of funding that the World Bankprovides for storage dam projects.Nonetheless, China continues to build storagedams, and the country now has roughly half ofall major storage dams in the world.Kreutzmann, H. (2004) ‘Staudammprojekte inder Entwicklungspraxis: Kontroversen andKonsensfindung’, Geographische Rundschau,vol 12, pp4–9.

11 Badische Zeitung, 31 May 2003.12 As in biogas units, the anaerobic decomposi-

tion of biomass releases methane, hydrogensulfide and ammonia.

13 Kohlhepp, G, (1998) ‘Große

Staudammprojekte in Brasilien’,Geographische Rundschau, vols 7–8,pp428–436.

14 Blume, G. (2006) ‘Eine neue Mauer’, Taz, 22May 2006.

15 REN21, Global Status Report 2005, p8f.16 Sanner, B. (2002) ‘Das Geothermiezeitalter

wird eingeläutet’, Erneuerbare Energien, vol2, pp52–55.

17 The geysers produce 7784GWh of power peryear, see http://iga.igg.cnr.it/geoworld.

18 www.geothermal-energy.org/210,welcome_to_our_page_with_data_for_indonesia.html.

19 In Reykjavik, pavements and car parks arekept free of snow with geothermal heat.

20 www.nea.is/geothermal/electricity-generation.21 BINE (2001), ‘Geothermie’, basisEnergie 8,

February 2001.22 Zukunftsenergien aus Nordrhein-Westfalen,

Düsseldorf 2002, p52.23 This kind of geothermal power production

does not use boiling water (as is common inconventional power plants), but rather a fluidwith a lower boiling point (such as purehydrocarbons). Such an ORC process cangenerate electricity starting at temperaturesabove 100°C.

24 Levermann, E. M. (2004) ‘“Heißer Strom” aus2.200 Meter Tiefe’, Sonnenenergie, May2004, pp32–34.

25 Geothermal electricity generation in Soultz-sous-Forêts ; BINE-Projektinfo 04/2009,www.bine.info/en.

26 ‘Bad Urach erschließt gigantischeEnergiequelle’, Schwäbische Zeitung, 27 April2002.

27 ‘Am Oberrhein boomt die Erdwärme’,Badische Zeitung, 23 December 2004.

28 Marter, H. J. (2002) ‘Strom aus der Tide’,Neue Energie, vol 11, pp60–62; (2003) ‘Rotorunter Starkstrom’, Neue Energie, vol 8,pp58–60; and (2005) ‘Lange Wellen’, NeueEnergie, vol 10, pp84–88; (2004) ‘Seaflow –Strom aus Meeresströmungen’BINEProjektinfo, vol 4

29 Graw, K. U. (2006) ‘Stand and Perspektivender Nutzung der Meeresenergie’,Energiewirtschaftliche Tagesfragen, vol 3,p59ff. Starting in 2008, a Pelamis system wasto provide power for 2000 homes off theOrkney Islands. The Scottish government plansto provide nearly €20 million for this project;Strom von der Seeschlange; www.energiepor-tal24.de on 28 February 2007;www.pelamiswave.com/content.php?id=159

229

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Chapter 8

1 BINE (2001) ‘Geothermie’, basisEnergie 10,December 2001.

2 Auer, F. and Schote, H. (2008) Nicht jedeWärmepumpe trägt zum Klimaschutz bei,Schlussbericht des zweijährigen FeldtestsElektro-Wärmepumpen am Oberrhein, Lahr2008, www.agenda-energie-lahr.de.

3 ‘Wärmepumpen durchgefallen’,Energiedepesche, March 2001.

4 It follows that the environmental impact ofhydrogen mainly depends on how it is created(with power from coal plants, nuclear poweror renewable energy).

5 In catalytic combustion, hydrogen directlyreacts with air in contact with a catalyst (suchas platinum) at relatively low temperatures.Catalysts are therefore very efficient and havevery low emissions, especially of nitrous oxide.

6 The drawbacks are just as apparent, however.If hydrogen is to be ‘green’, it will have tocome from renewable energy. Unfortunately,because renewable electricity is still relativelyexpensive and so much energy is lost inconversion, green hydrogen would be evenmore expensive.

7 An exhibition of the LandesgewerbeamtBaden-Württemberg and the DeutscheForschungs- and Versuchsanstalt für Luft andRaumfahrt (1988/1989) had the same title;see Scheer, H. (ed) (1987) Die gespeicherteSonne: Wasserstoff als Lösung des Energie-and Umweltproblems, Serie Piper, Munich; ormore recently Rifkin, J. (2002) Die H2-Revolution, Campus Sachbuch.

8 Seifried, D. (1986) Gute Argumente: Energie,Munich.

9 Nitsch, J., Dienhart, H. and Langnis, O. (1997)‘Entwicklungsstrategien für solare energie-systeme. Die rolle von wasserstoff inDeutschland’, in EnergiewirtschaftlicheTagesfragen, vol 4, pp223–229; Dirschauer,W. (2003) ‘Wasserstoff – kein königsweg derenergieversorgung’, EnergiewirtschaftlicheTagesfragen, vols 1–2, pp87–89; Fischedick,M. and Nitsch, J. (2002) Langfristszenario füreine Nachhaltige Energienutzung inDeutschland, Forschungsbericht Bundes-ministerium für Umwelt, Berlin.

10 Pehnt, M. (2002) EnergierevolutionBrennstoffzelle? Perspektiven, Fakten,Anwendungen, Weinheim 2002

11 For example, in the autumn of 2006,

Taiwanese electronics firm Antig produced acharging device powered by a fuel cell for smallappliances. The sales price of around US$2000,however, will mean that the device is onlyaccepted in a small number of niche applica-tions; www.initiative-brennstoffzelle.de, 13October 2006.

12 The utilities expect that they will own fuelcells, take the power on the grid, sell the heat,and thereby enter the heating market.

13 Vaillant’s estimate, www.initiative-brennstof-fzelle.de (November 2006), IBZ-Nachrichten,December 2008; www.ibz-info.de

14 But things will not change overnight; there isalso a lack of technical standards for hydro-gen lines to residential areas, for instance.Deutscher Bundestag, 14/5054.

15 Deutscher Bundestag, 14/5054, p102.16 Deutscher Bundestag, 14/5054, p46.17 Erste Brennstoffzellen-Flotte geht in den

Praxistest, Dpa, 7 October 2002.18 ‘Wasserstoffantrieb als Auslaufmodell’,

Solarzeitalter, vol 4, 2009, p106,www.eurosolar.org.

19 In 2006 the German Ministry ofTransportation estimated that the marketmaturity of fuel-cell cars will take about tenyears, Badische Zeitung, 31 October 2006.

20 Langer, H. (2003) ‘Brennstoffzellen-Tagung:Verhaltene Äußerungen zu denMarktchancen’, Sonnenenergie, January2003, p. 34f. And there is another obstacle:switching vehicles to fuel cell drive trains willrequire considerable changes in industry (suchas engine construction).

21 In a cost/benefit analysis, Germany’sEnvironmental Protection Agency found thatemissions reductions and resource protectionwould be much cheaper if classic drivetrainswere optimized than if vehicles wereequipped with fuel cells. DeutscherBundestag, 14/5054, p65.

22 Measured as CO2 equivalent.23 The use of renewable electricity to produce

hydrogen is counterproductive in terms ofclimate policy as long as the specific emissionsof merit-order power are above 190g CO2-eq/kWh. See Ramesohl, S., et al. (2003)Bedeutung von Erdgas als neuer Kraftstoff imKontext einer nachhaltigen Energieversorgung,Wuppertal Institute for Climate, Environmentand Energy, Wuppertal.

24 DaimlerChrysler (2003) Umweltbericht.

230



Chapter 9

1 DLR, IFEU and Wuppertal Institute (2004)Ökologisch optimierter Ausbau der Nutzungerneuerbarer Energien in Deutschland.Forschungsvorhaben im Auftrag desBundesministeriums für Umwelt, Naturschutzand Reaktorsicherheit, Stuttgart, Heidelberg,Wuppertal. The authors make a distinctionbetween two different types of potential. Inthe basic version, they determined the techni-cal, structural potential that takes account ofthe main requirements for nature conserva-tion, such as connections of wind farms innature conservation areas. In the NatureConservation Plus version, lower potential wasdetermined under stricter nature conservationrequirements (indicated in parentheses here).In the values indicated, a middle scenario wasgiven for biomass, which can be used in anumber of ways. In scenario A (100 per centstationary use), the potential is 180TWh forelectricity and 1130PJ of heat; in the otherscenario (100 per cent fuels), all biomass usefor fuels would amount up to 1000PJ.

2 In the version without the use of heat incogeneration units, the figure is 290TWh;with heat usage, the potential of geothermalelectricity drops to 66TWh.

3 BMU (2009) Erneuerbare Energien in Zahlen,Berlin, June 2009.

4 BMU (2006) Erneuerbare Energien in Zahlen,Berlin, May 2006.

5 www.solarwaerme-plus.info.6 Bundesverband Solarwirtschaft, June 2006.7 Resolution of the European Parliament on 13

March 2002; Deutscher Bundestag 14/9670.8 Here, 16 systems were tested, 15 of which

were found to be good or very good. StiftungWarentest, vol 4, 2002.

9 Kommission der EuropäischenGemeinschaften, Energie für die Zukunft:Erneuerbare Energieträger, Weißbuch für eineGemeinschaftsstrategie and Aktionsplan.

10 Kommission der EuropäischenGemeinschaften, Energie für die Zukunft:Erneuerbare Energieträger, Weißbuch für eineGemeinschaftsstrategie and Aktionsplan, p8.

11 h t t p : / / e u ro p a . e u / d o c u m e n t s / c o m m /white_papers/pdf/com97_599_en.pdf.

12 Directive 2001/77/EC of the EuropeanParliament and Council on 27 September2001. Official Journal of the European UnionL283/33 on 27 October 2001.

13 RL 2009/28/EG.14 Data from 2002; Reiche, D. and Bechberger,

M. (2005) ‘Erneuerbare Energien in den EU-Staaten im Vergleich’, EnergiewirtschaftlicheTagesfragen, vol 10, pp732–739. The largeshare of hydropower also indicates whySweden and Austria actually had lower sharesof renewable power in 2003 then they had in1997; less precipitation means less electricityfrom hydropower.

15 Reiche, D. and Bechberger, M. (2005)‘Erneuerbare Energien in den EU-Staaten imVergleich’, p732f; BMU (2006) ErneuerbareEnergien in Zahlen, Berlin.

16 Reiche D. and Bechberger, M. (2005)‘Erneuerbare Energien in den EU-Staaten imVergleich’, p732f; BMU (2006) ErneuerbareEnergien in Zahlen, Berlin.

17 BMU (2009) Erneuerbare Energien in Zahlen,Berlin, p51.

18 Reiche, D. and Bechberger, M. (2005)‘Erneuerbare Energien in den EU-Staaten imVergleich’, pp732–739.

19 Because Italy and Luxembourg passed newlaws in March 2004, the European commis-sion has not performed any reviews.Commission communiqué: The share ofrenewable energy in the EU. {SEK(2004) 547}26 May 2004.

20 In a review of literature, researchers Ezzati, M.and Kammen, D. found that some 1.5–2million deaths were the result of smoke fromsolid fuels worldwide in 2000. (2005) REN21Renewable Energy Policy Network:Renewable Energy 2005 Global Status Report,Washington, DC, Worldwatch Institute, p29.


22 China made up some 80 per cent of globalgrowth in collector area in 2004. REN21(2005) Global Status Report 2005, p25.

23 REN21 (2005) Global Status Report 2005,p25.


25 Lehmann, H., et al. (1998) Long-TermIntegration of Renewables Energy Sourcesinto the European Energy System, The LTIResearch Team, Physica Verlag.

26 Langniß, O., Luther, J., Nitsch, J. andWiemken, E. (1997) Strategien für eine nach-haltige Energieversorgung – Ein solaresLangfristszenario für Deutschland, Freiburg,Stuttgart.

231

Notes


27 DLR, IFEU and Wuppertal Institute (2004)Ökologisch optimierter Ausbau der Nutzungerneuerbarer Energien in Deutschland.Forschungsvorhaben im Auftrag desBundesministeriums für Umwelt, Naturschutzand Reaktorsicherheit, Stuttgart, Heidelberg,Wuppertal.

28 In this calculation, power from renewables iscompared to the primary energy that wouldhave been needed to produce the sameamount of electricity in thermal power plants(substitution method).

29 REN21 (2005) Global Status Report.30 www.eee-info.net31 DeNet (2009) Wege in eine erneuerbare

Zukunft, Kassel, www.100-ee.de.32 Köpke, R. (2004) ‘Auf ewig heiß’, Neue

Energie, October, pp85–91.33 ABC News (2008) ‘Iceland moves to hydrogen

power for ships’, 23 January 2008,www.abc.net.au.

Chapter 10

1 Langniß, O. (1997) Strategien für eine nach-haltige Energieversorgung – Ein solaresLangfristszenario für Deutschland,Freiburg/Stuttgart, p37.

2 Systems in which a steam turbine is hookedup behind the gas turbine. These systems aregenerally powered with gas or with gas andcoal.

3 See glossary.4 Lönker, O. (2005) ‘Zukunftsspeicher’, Neue

Energie, April, pp30–36.5 Engel, T. (2006) ‘Der Ausbau erneuerbarer

Energien braucht keine Speicher sondernVerbraucher’, DGS newsletter, 2 November2006.

6 www.thema-energie.de, the Alabama ElectricCorporation has been operating acompressed air power plant since 1991(110MW), in McIntosh, Alabama.

7 Lönker, O. (2005) ‘Zukunftsspeicher’, NeueEnergie, April, p34.

8 Proposal made by Michael Vandenbergh(ISET), Engel, T. (2006) ‘Der Ausbau erneuer-barer Energien braucht keine Speichersondern Verbraucher’, DGS newsletter, 2November 2006. Another proposal is to userefrigerator systems to store electricity: ‘Atnight, large refrigerator systems would reducetheir temperature by a degree when energyconsumption is low. But during the day, when

energy consumption is high, they wouldincrease their temperature by a degree. In theprocess, these cooling systems would func-tion as batteries. Large refrigerator buildingshave a storage capacity of 50,000MWh.’www.sonnenseite.com, 11 February 2007.

9 A fifth possibility is not considered because ofthe risks it entails: nuclear energy.

10 PROGNOS, DLR, Institute of Applied Ecologyand Wuppertal Institute (1998)Klimaschutzkonzept für das Saarland,Untersuchung im Auftrag des Ministeriumsfür Umwelt, Energie and Verkehr desSaarlandes, Berlin, Stuttgart, Freiburg,Wuppertal.

11 Pick, E. and Wagner, H. J. (1998) ‘Beitrag zumkumulierten Energieaufwand ausgewählterWindenergiekonverter’, Arbeitsbericht, July1998, Institut Ökologisch verträglicheEnergiewirtschaft, Universität GH Essen

12 Neue Energie, September, p8 andwww.dasgruene-emissionshaus.de.

13 Wagner, H. J. (2002) ‘Energie- andEmissionsbilanz von Solaranlagen’, VDIFortschrittberichte, no 194, Düsseldorf,pp17–33; Stiftung Warentest, April

14 Kreutzmann, A. and Welter, P. (2005) ‘Mehrraus als rein. Neue Energiebilanzen belegenkurze Energierücklaufzeiten vonPhotovoltaikanlagen’, Photon, September2005, pp66–69.

15 Here, the argument is that expanding renew-ables will increase retail electricity rates,thereby making the German industry slightlyless competitive. The second aspect is lowerdemand. The money spent on a solar arraycannot be used for other consumer items. Asa result, jobs are lost in other sectors.

16 ‘Nachhaltige Energiewirtschaft, Einstieg in dieArbeitswelt von morgen’, Institute of AppliedEcology, Freiburg, Darmstadt, Berlin 1996

17 Wind Kraft Journal, February, p44.18 Because of the leading role that Denmark

plays in this sector, Danish manufacturershave long dominated the global market forwind turbines (see 6.5).

19 BMU (2009) Erneuerbare Energien in Zahlen.20 Kommission der Europäischen

Gemeinschaften, Energie für die Zukunft:Erneuerbare Energieträger, Weißbuch für eineGemeinschaftsstrategie and Aktionsplan,p15.

21 Seifried, D. (1986) Gute Argumente: Energie,Munich, p97.

232



22 Mez, L. (2001) ‘Fusionen: Das große Fressen’,Energiedepesche, June 2001

23 Verband der Deutschen Elektrizitätswirtschaft(VDEW): Strombilanz project group, 4September 2006. See also Bömer, T. (2002)‘Nutzung erneuerbarer Energien zurStromerzeugung im Jahr 2000’,Elektrizitätswirtschaft, vol 7, pp22–32

24 BMU (2006) Erneuerbare Energien in Zahlen,Berlin.

Chapter 11

1 Over the years, various ministries havehandled energy research, and the approacheshave not always been clearly formulated. Thecategorization used here is the one set forthin the 3rd Energy Research and EnergyTechnologies Programme (1990–1995).

2 Deutscher Bundestag, 13/1963, p62ff,personal contact with Joachim Nitsch andwith BMWi and BMBF.

3 BMBF (1996) 4rd Energy Research and EnergyTechnologies Programme, Bonn, p87.

4 Deutscher Bundestag, 14/8015.5 Lönker, O. (2006) ‘Forschen für Energie’,

Neue Energie, vol 4, pp22–27; BMWA (2005)‘Innovation and neue Energietechnologien’,Das fünfte Energieforschungsprogramm derBundesregierung, Berlin.

6 Lönker, O. (2006) ‘Forschen für Energie’,Neue Energie, vol 4, pp22–27.

7 Council decision of 18 December 2006concerning the 7th Framework Programme ofthe European Atomic Energy Community(Euratom) for nuclear research and trainingactivities (2007–2011) (2006/970/EURATOM).

8 Langniß, O., et al (1997) Strategien für einenachhaltige Energieversorgung – Ein solaresLangfristszenario für Deutschland,Freiburg/Stuttgart.

9 After the Cole compromise of 13 March1997, the German federal governmentoffered financial aid for the sale of electricityfrom coal and coal briquettes from1997–2005 (nine years) in addition to fundingfor future shutdowns of coal mines in theamount of €28 billion. A further €1.3 billionwas provided for the takeover ofSaarbergwerke AG by Ruhrkohle AG. Overall,the subsidies amount to €3.3 billion per yearduring those nine years. In 2004, the govern-ing coalition reached an agreement to extendthe financing. From 2006–2012, the hard coal

sector will receive just under €16 billion inpublic funding. In 2005, the sector received€2.8 billion; Die Welt, 9 November 2005.

10 According to German TV channel ARD,Germany consumes some eight million tonsof kerosene per year. Each litre is exemptedfrom roughly 60 cents of mineral tax in addi-tion to sales tax.

11 A total of around €510 million over five years.12 Umweltministerium and Wirtschafts-

ministerium Baden-Württemberg (2006)Erneuerbare Energien in Baden-Württemberg2005, Stuttgart; preliminary values for feed-inrates in 2005: 45.4 billion kilowatt-hours,€4.4 billion.

13 Based on an average of 6 eurocents per kilo-watt-hour.

14 Prognos AG (1992) Die externen Kosten derEnergieversorgung, Stuttgart.

15 Hohmeyer, O. (1991) ‘Least-Cost Planningand soziale Kosten’, in Hennicke, P. (ed.) DenWettbewerb im Energiesektor planen,Heidelberg, New-York, Tokyo. The externalcosts of conventional power generation aregreater than the feed-in rates paid inGermany, as Hohmeyer shows in a report forGermany’s Environmental Protection Agency.Hohmeyer, O. (2001) Vergleich externerKosten zur Stromerzeugung in Bezug auf dasErneuerbare Energien Gesetz, Flensburg.

16 This is mainly due to the risk of malfunctionsand the tremendous costs of a nuclear disas-ter. Up to now, damage has only beencovered in insurance policies up to DM500million – too little, as Ewers and Gellingreveal. The two researchers estimate that thepossible damage amounts to around €2000billion. And while such an amount can beensured, the damage that such a disasterwould have at an atomic plant could not beundone. Not even with trillions of euros canwe bring people back to life or make radioac-tive land liveable again. In other words, evenif we include the social costs of nuclear powergeneration, which Hohmeyer puts at 5–36eurocents per kilowatt-hour, that only meansthat these costs can be attributed to atomicenergy, not that the damage could be madeundone with that money.

17 For instance, a study by DLR and theFraunhöfer Institute for Systems andInnovation Research (ISI) found that the costspassed on to customers as part of the feed-inrates are lower than the external costs ofpower generated in fossil power plants.

233

Notes


DLR/ISI (2006) Externe Kosten derStromerzeugung aus erneuerbaren Energienim Vergleich zur Stromerzeugung, Karlsruhe.

18 To the extent that the electricity tax does notexceed €511 per year.

19 At an overall efficiency of at least 70 per cent.20 Ecologic, Institut für Internationale and

Europäische Umweltpolitik gGmbH andDeutsches Institut für Wirtschaftsforschung(DIW) im Auftrag des Umweltbundesamtes:Auswirkungen der ÖkologischenSteuerreform auf private Haushalte, Band IIIdes Endberichts für das Vorhaben:‘Quantifizierung der Effekte der ÖkologischenSteuerreform auf Umwelt, Beschäftigung andInnovation’, August 2005.

21 Conze and Bitter (Stiebel Eltron) (1998)Gesamtförderung 1997 von BUND, Ländern,Kommunen und EVUs, 3 July 1998.

22 Lackschewitz, U. (GUT) (1998) ThermischeSolaranlagen in Wohngebäuden, Auswertungdes Solarthermischen Förderprogramms desLandes Hessen für die Jahre 1992–1996,Hessisches Ministerium für Umwelt, Energie,Jugend, Familie und Gesundheit, Kassel 1998,p7.

23 Lackschewitz, U. (GUT) (1998) ThermischeSolaranlagen in Wohngebäuden, Auswertungdes Solarthermischen Förderprogramms desLandes Hessen für die Jahre 1992–1996, p82.

24 Staiß, F. (2003) Jahrbuch erneuerbarerEnergien 2002/2003, Bieberstein, p162ff;www.solarfoerderung.de

25 Lackschewitz, U. (GUT) (1998) ThermischeSolaranlagen in Wohngebäuden, Auswertungdes Solarthermischen Förderprogramms desLandes Hessen für die Jahre 1992–1996, p19;Landtag Baden-Württemberg, 12/1840, p5.The higher rate in the state of Hessen did notlead to greater growth; obviously, otherfactors are crucial for market development(such as general information and businessactivity).

26 Landtag Baden-Württemberg, 12/1840,12/2340, 12/3635.

27 Lackschewitz, U. (GUT), (1999), ibid, p. 16and p. 74; Landtag Baden-Württemberg11/6318, II.1. and 12/242

28 Bleyl, J.; Krüger, K.: Solares Contracting.Sonnenenergie 1/2001, p. 24f. For furtherexamples, see Sonnenenergie, 11/2002, p.22f

29 As part of the German government’sSolarthermie2000plus, several demonstrationprojects were conducted. Wärme für viele:

Wohn- and Bürohäuser im Visier, NeueEnergie, v. 2, 2007, p. 34

30 Erstes Gesetz zur Änderung des Gesetzes zurFörderung der sparsamen sowie umwelt- andsozialverträglichen Energieversorgung andEnergienutzung im Land Berlin, 12 October1995

31 „Leere Versprechungen?”, Solarthemen no.130, 28.2.2002, p. 2

32 “Berlin soll sich an Barcelona ein Beispielnehmen” Neue Energie 2/2002, p. 52f; „KeinNeubau ohne Solaranlage”, Sonnenenergie,March 2002, p. 48f.

33 For instance, the share of wind in total powerconsumption in Schleswig-Holstein exceeded15 per cent in 1999, DEWI-Magazin, no 15,August 1999.

34 Gesetz für den Vorrang ErneuerbarerEnergiequellen (Erneuerbare-EnergienGesetz), 21.7.2004, which went into effect inAugust 2004

35 Feed-in rates are passed on as a surcharge ontop of retail electricity prices. Currently, thesurcharge amounts to about 2 cents per kilo-watt-hour. For large industrial powerpurchasers, whose electricity costs make up15 per cent of gross added value or more, aspecial rule applies so that these consumersonly pay an extra 0.05 cents per kilowatt-hour.

36 The feed-in rates applicable to the year of gridconnection applies for 20 calendar years start-ing on the day of grid connection up toDecember 31 of the final year.

37 Compensation is subject to certain terms, seeSection 6 EEG.

38 The floor rate for systems connected to thegrid in subsequent years drops by 1 per centper annum.

39 See Section 8 EEG, which specifies variouscompensation targets for electricity frombiomass.

40 See Section 10 paragraph 3 EEG41 Global Status Report Renewables, 2006

Update, p. 2342 Global Status Report Renewable Energy,

2005, p. 21f43 Renewables Global Status Report 200944 www.renewableenergyworld.com/rea/news/

article/2009/07/britain-to-launch-innovative-feed-in-tariff-program-in-2010 andwww.fitariffs.co.uk.

45 Manteuffel, B.: Size matters, Sonnenenergie,Nov. 2004, p. 16-19

46 For instance, the regional Schwarzwald- Baar-

234



Heuberg (Baden-Württemberg) Associationwarned of a blight on the landscape inAugust 2004. dpa, 18.8.2004

47 Section 11, paragraph 3 EEG48 Photon, June 2006, p. 7249 www.reuters .com/ar t i c le / rbssUt i l i t ies

Multiline/idUSN205053362009032050 BMU: Konsultationspapier zur Entwicklung

eines Instruments zur Förderung der erneuer-baren Energien im Wärmemarkt. Berlin, 24May 2006

51 Such contracts are private law agreementsbetween the community and propertypurchasers in Germany. The section 23b ofparagraph 9 of the Building Act serves as thebasis; it specifies that “certain measures forthe use of renewable energy” can berequired.

52 ‘Kein Neubau ohne Solaranlage’,Sonnenenergie, March 2002, p48f; forfurther information, see www.icaen.net.

53 Quilisch, T. and Peters, Chr. (2005)Solarthermie in Katalonien. KommunaleSolarverordnungen als Erfolgsmodell, Vortragauf dem Exportforum, Hannover, 14 May2005.

54 CDU-SPD coalition agreement in November2005, p51.

55 BMU: Konsultationspapier zur Entwicklungeines Instruments zur Förderung der erneuer-baren Energien im Wärmemarkt. Berlin, 24May 2006, www.bmu.de.

56 ibid.57 EU directive 2003/87/EC.58 Oberthür/Ott: The Kyoto-Protocol, Berlin,

Heidelberg, New York 1999.59 www.thema-energie.de and www.initiative-

energieeffizienz.de.60 RAVEL is an abbreviation for Rationelle

Verwendung von Elektrizität. In thiscampaign, the Swiss focused on specifictarget groups for power conservation.Application-oriented research, further trainingfor installers and engineers, demonstrationprojects, and awareness-raising were part ofthe campaign.

61 The reference showed how carbon emissionswould have developed if nuclear plants havebeen left in operation.

62 Öko-Institut 1996: Das Energiewende-Szenario 2020. Ausstieg aus derAtomenergie, Einstieg in Klimaschutz andnachhaltige Entwicklung. Darmstadt,Freiburg, Berlin 1996.

63 International Solar Energy Society 2002:

Sustainable Energy Policy Concepts (SEPCo).Studie für das Bundesministerium für Umwelt,Naturschutz and Reaktorsicherheit, Freiburg2002. For further information, seehttp://www.ises.org/shortcut.nsf/to/ICNFINAL.

Chapter 12

1 Forsa (2005) ‘Meinungen zu erneuerbarenEnergien’, poll taken on 27/28 April 2005.

2 Forsa survey on renewables in January 2010,www.unendlich-viel-energie.de.

3 Güllner, M. (Forsa) (1999) ‘Das Marktpotentialand die Zielgruppe für “Öko-Strom”’, Thesenim Rahmen des ASEW-Seminars: Top oderFlop? Ökostrom aus der Sicht der Stadtwerke,27/28 April 1999 in Heidelberg.

4 www.ecotopten.de/prod_strom_prod.php.5 From an ecological point of view, it does not

matter whether clean power is generatedsimultaneously or earlier or later than it isconsumed.

6 The Wuppertal Institute has come up with aconcept for the assessment of an energyprovider’s sustainability services:‘Energieversorger auf dem Prüfstand’,Wuppertal Papers no 116, 2001.

7 The figures given here represent theFreiburger Regio-Solarstromanlage: Wiese, R.(1997) ‘Regio-Solarstromanlagen’,Sonnenenergie, vol 5, pp34–35. For anoverview of various business models, seeCottmann, T. (1997) ‘PV-Betreibergemeinschaften: GmbH & Co KG?’Sonnenenergie, vol 5, p36f; Bernreuter, J.(2002) ‘Mehr Risiko oder mehr Kosten’,Photon, February 2002, pp36–39. The guide‘Bürger Solarstrom Anlagen’, Verlag SolareZukunft, Erlangen, is interesting for peoplewho want to set up a community solar powerarray. See also www.bwebuecher. de.

8 For example, the Öko-Strombörse at the BernUtility had 450kW of solar power undercontract in the first year; Der Bund, 19February 1999.

9 Elektrizitätswerke Zürich (EWZ), media confer-ence on 15 April 1997.

10 It was called EKZ Naturstrom solar,www.ekz.ch/internet/ekz/de/kundendienst.

11 The Industrial Works of Basel offered such aprogramme, for example. But the programmewas discontinued at the end of 2006.

12 www.eco-watt.de.13 Seifried, D. (2008) Making Climate Change

235

Notes


Mitigation Pay: Eco-Watt: The Community-Financed Negawatt Power Plant, Freiburg.

14 ‘100,000W Solar-Initiative für Schulen inNordrhein-Westfalen – Energieschule 2000+’is a project of LandesinitiativeZukunftsenergien NRW. The German state ofNorth Rhine Westphalia promoted theproject’s design.

15 With hydraulics, the flow within a heatingsystem is optimized. In principle, only theamount of water needed to heat a section ofthe building should flow through the pipes.

16 In this school, the heating and ventilationsystem was completely renovated, and acogeneration unit and solar array, each withan electric output of 50kW, were installed;www.solarundspar.de.

17 www.solarundspar.de.18 IEA 2006 (2006) Light’s Labour’s Lost, Paris,

p25.19 IEA 2006 (2006) Light’s Labour’s Lost, Paris,

p468.

236



AbsorberPart of a solar collector; see 2.1.

Air collectorsThese devices use solar energy to heat air;see 2.5.

Auxiliary boilerA boiler used alongside the principal boiler(such as a wood-fired boiler) to provide extraheat on days of peak demand.

BaseloadThe level of power that is needed all thetime, day and night, summer and winter;also see ‘peak load’.

BiogasGas created in an oxygen-free environmentwhen biomass (especially excrement)ferments; see 5.2 and 5.3.

BiomassSee Chapter 5.

Climate policyPolicies designed to slow down or preventglobal warming (see ‘greenhouse effect’).Because carbon emissions are a main causeof the greenhouse effect, climate policiesoften aim to reduce carbon emissions.

Cogeneration unitA system that generates electricity but alsosupplies its waste heat as useful heat. Forinstance, a (gas) motor can be used to drivea generator. In addition to the electricity, thewaste heat from the motor would also beused; see 1.9 and 5.3.

CollectorsConvert sunlight into heat; see 2.1.

Community projectsSee 12.3.

Condensation boilerA gas or oil heater with especially great effi-ciency. The water vapour in the waste gascondenses, thereby increasing overall effi-ciency.

ContractingA way of financing a new, more efficientsystem (such as lighting or ventilation) withfuture savings from lower energy costs. Thecontractor plans the investment, thenfinances and implements it. In return, thecontractor receives the difference betweenthe old and the new energy costs over aspecified period; see 12.6 and 12.7.

Conventional powerPower from a central plant whose wasteheat from power production simply escapesinto the atmosphere; such plants generallyhave a relatively low efficiency of around 30to 45 per cent.

Demand managementWhen demand for power is greater than thecapacity of power plants, there are two solu-tions: either power plant capacity can beincreased, or some power consumers can bebriefly switched off. The second option iscalled demand management.

Diffuse/direct sunlightThe sunlight that reaches the Earth in acloudless sky from a particular angle is calleddirect sunlight. In contrast, diffuse sunlight isrefracted by clouds, smog, fog, etc. and itreaches the Earth’s surface from differentangles; see 1.6.

237

Glossary


District heating networkAn insulated network of pipes which supplyheat from a central heating/solar system toconsumers nearby; see 2.3 and 5.5.

Eco-taxationA tax on the consumption of resources; inGermany, the tax has been applied to oil,natural gas, petrol and electricity; see 11.4and 11.5.

EfficiencyThe ratio between energy input and energyoutput. For instance, if 100,000kWh ofenergy is put into a power plant as fuel(energy input), and the power plant usesthat energy to generate 35,000kWh of elec-tricity, the efficiency is 0.35 or 35 per cent.

ElectrolysisWhen electricity is used to break up a chem-ical compound; for instance, electrolysis cansplit water into oxygen and hydrogen.

Energy-conservation ordinanceThis German law currently sets a limit onenergy consumption in buildings; see 4.1.

Energy cropsPlants grown especially as energy sources;see 5.1 and 5.6.

Feed-in ActA German law obligating grid operators topay a floor price for renewable electricityexported to their grids. In 2000, it wasreplaced by the Renewable Energy Act(EEG); see 11.9.

Feed-in ratesA floor price paid for electricity exported tothe grid.

Final energyThe energy provided to consumers (homes,industry, vehicles, etc.); in other words, theenergy provided after primary energy has

been converted in refineries, power plants,etc. and distributed over the electricity grid,filling stations, etc.

Forestry wasteWood collected in forest management thatis too small to be used in sawmills. It can,however, still be used to make particle boardor as a source of energy (wood chips andwood pellets); see Chapter 5.

Fossil energy sourcesCoal, petroleum and natural gas, whichcontain solar energy stored from previousmillennia; they are all the products ofgeologically captured plant matter.

Fuel cellA source of electricity (and heat) in which afuel’s chemical energy (such as hydrogen ornatural gas) is directly converted into elec-tricity. The heat created in the process canalso be used.

Gas turbineA special turbine that can easily be rampedup and down; see 10.1.

GeothermalThe use of underground heat as a source ofenergy.

Green powerElectricity from renewable energy; see 12.2.

Greenhouse effectHeat-trapping gases in the Earth’s atmos-phere (mainly carbon dioxide, methane,laughing gas, etc.) prevent heat from escap-ing into outer space. As a result, the Earth’satmosphere heats up; see 1.1.

Grid-connected solar arraysPhotovoltaic systems which do not have abattery to store solar energy. The power thatis not consumed locally is exported to thegrid; see 3.2.

238



Grid transit feesThe fees that are charged when electricitytravels through another company’s grid.

Heat Conservation OrdinanceA German law that specified maximumheating demand in new buildings; in 2002 itwas replaced by the Energy ConservationOrdinance; see 4.1.

Heat recoveryIn buildings, heat exchangers are often inte-grated into ventilation systems. They takeenergy out of the warm outgoing air anduse it to preheat colder incoming air. Theefficiency of modern heat exchangers insuch systems exceeds 90 per cent.

Insulating glassWindow panes that are good insulators; see4.2.

Liberalization of the energymarketSee 1.10.

Low-energy houseA house with low heating energy demand;see 4.1.

Municipal utilitiesUtility companies that provide electricity, gasand possibly water generally within the citylimits

NegawattsSee 12.7.

Nuclear fusionIn nuclear fusion, energy is generated whennuclear atoms melt. At present, nuclearfusion is a long way from being a viabletechnical application (see 11.1).

Off-grid solar houseSee 4.7.

Offshore turbinesWind turbines installed in shallow wateroffshore.

Passive houseA house with very low heating energydemand; it can even do without a conven-tional heating system; see 4.6.

Passive solar energySee 4.2.

PaybackThe time it takes for an investment to pay foritself. Energy payback is the time a renew-able energy system needs to generate theenergy used for its manufacture; see 10.4.

Peak loadTimes when demand for power is at itshighest; generally, the demand only lasts afew hours or a few days a year; see ‘base-load’.

Photovoltaics These systems directly convert solar energyinto electricity; see Chapter 3.

Plus-energy houseA house that generates more energy than itconsumes; see 4.8.

Primary energyCoal, natural gas, petroleum, wind, flowingwater, sunlight, biomass and geothermalheat are primary sources of energy. Theenergy contained in them is called primaryenergy. In contrast, electricity is a secondarytype of energy because it does not directlyoccur in nature, but must first be createdfrom primary energy sources.

Pumped storageSee ‘storage power plant’.

Quota modelSee 11.13.

239

Glossary


Renewable Energy Act (EEG)The German law that replaced the Feed-inAct; see 11.10.

Run-of-river power plantHydro plants that use flowing river water togenerate electricity. Generally, there is littledifference between the level of water oneither side of the dam, but the amount ofwater is great. For economic reasons, suchdams are generally constructed with sluices.

ScenarioA model for the future based on certainassumptions and mathematical equations;see 9.6.

Service waterHot water used in bathrooms and kitchens.

Solar hydrogenHydrogen made from solar energy as a wayof storing energy; see 8.2.

Solar ordinanceAn ordinance that obligates some or allbuilders to install solar arrays; see 11.14.

Solar power exchangeAn agency that brokers between buyers andsellers; see 12.4.

Solar thermalThe use of solar energy to create heat; seeChapter 2.

Solar thermal power plantsPower plants that use solar energy to heatup on the heat carrier (such as water oranother fluid) to generate electricity with anormal steam-driven generator; see 2.6.

Storage power plantHydro plants that utilize differences in alti-tude, such as around mountain lakes.Pumped storage plants are a special type;here, inexpensive electricity (such as power

at night) is used to pump water up to astorage basin, and when power is neededduring peak demand, the water can be letthrough to drive a turbine and generateelectricity at times when power is moreexpensive; see 10.2.

SustainableAn economic activity is considered sustain-able if it does not consume resources fasterthan they can regenerate.

Transmission lossesHeat losses that occur when energy passesthrough parts of the house, such as walls,the roof and windows. Insulation reducestransmission losses.

Transparent insulationSpecial insulation applied to the outside of ahouse to capture solar energy; see 4.5.

Wind farmA project consisting of numerous windturbines.

Woodchip heatingHeating systems fired with timber choppedup into chips; see 5.5.

Wood pelletsA special fuel for wood heating systems.Wood pellets are some 6–12mm long andgenerally consist of waste wood products;the pellets themselves have standardizedproperties, such as moisture content andheating value; see 5.4.

240



acid rain 170Africa 50, 96, 109, 114, 115, 132Aggertal School 218agrarian policy 78agriculture 78, 80, 88, 96, 100, 174

sustainable 94air collectors 46, 48–9air-conditioning 46

adsorption 47air pollution 38all-in-one packages 214–15Alps 16, 124, 160alternative vs conventional fuel systems 91ambient air 40, 130, 134annual solar and wind patterns 155anti-corrosion 110armed combat 20Arctic 16Argentina 96artificial lighting 56Asia 106, 114Austria 84, 146, 152, 186

Baden-Württemberg 116, 118, 176, 190Bad Urach 126Baltic Sea 110Bangladesh 148Barcelona 178, 192

success of mandatory solar arrays in 193Bavaria 116, 124Bayernwerk AG 164BEWAG 164Big Four power providers, Germany 34,

36Binswanger, H.C. 100biodiesel 90–1, 93–5, 148, 152biodiversity 88, 92, 96biofuels 88, 92, 94–5, 140, 144, 148

is there enough land for 96–7biogas 78–81, 90, 95, 134, 152–4

cogeneration units 82–3digesters 11

biomass 8, 11, 12, 24, 26, 29, 58, 74,78–97, 140–3, 146, 149–54, 164–6,182, 184–6, 201, 206, 207, 210

-to-liquid (BTL) 94–5traditional 148

BMW 138boilers 11, 84

wood-fired 86Bonus Model, Germany 194boreholes 126Borna, Saxony 188Brazil 92, 96, 114, 120, 148Brandenburg, former East Germany 124Bremen, Germany 156Bulgaria 22Bureau of Statistics, Germany 182

cadmium telluride (CdTe) 60Canada 114, 186canola 90Carbo-V biodiesel 94carbon dioxide (CO2) emissions 16, 22, 24,

36, 80, 83, 87, 92, 139, 172, 196,203, 216, 219–20

cheaper ways to avoid 158–9concentration in atmosphere 17district heating network with woodchip

system 86cars 8, 37, 92, 152

fuel cell 138hybrid 156hydrogen 134

catalytic combustion 132Certified Emission Reduction Units (CER)

198CFCs 46Chernobyl 22, 24, 202China 56, 92, 108, 148, 186Choren 94Clean Development Mechanism (CDM)

198–9how it works 199

241

Index


climate change 8, 10, 14–16, 24, 38, 138, 170,

174, 202protection investing in 216–17policy 16, 22at stake 16–17

Climate Protection Act 192clouds 12, 24, 26, 154Club of Rome 18, 28coal 10, 16, 20, 22, 24, 28–9, 50, 60,

82–3, 101, 122, 134, 158, 160, 166,169, 170, 172, 188, 206–7, 209, 220

mining 100cogeneration 8, 36–7, 66, 76, 154, 158–9,

164, 208–9as bridge technology 28key factor in energy transition 32–3plants 28, 34units 82–4, 90, 134, 136–7, 150, 152–3,

174, 184, 218Cogeneration Act (Germany, 2002) 32Commission on Protecting the Earth

(Germany) 24, 28community projects for solar power 210–12compactness 66compensation for solar power with return

on investment 180–1Compressed air energy storage (CAES) 156concentrated solar power (CSP) 50concentrator systems 60condensation boiler 44–5, 130, 160conservation 28, 68, 140, 151, 188

energy 32, 36–7, 62, 66, 158–9, 162,166, 198, 216–18

and hydropower 118–19solar strategy requires 30–1and wind power 100–2

construction sector 62, 192conventional vs alternative fuel systems 91cooling with sun 46–7

example 46outlook 46technology 46

copper-indium-selenide (CIS) 60crop rotation 96

Cuba 58village school with solar power 58

cultural landscape, protection of 100current use and potential 140–53

Daimler-Chrysler 94, 138Darmstadt, Germany 72dedicated energy crops 78Denmark 32, 98, 104, 106, 110, 146, 162,

190depletion midpoint 18DESERTEC project 50Desiccant Evaporative Cooling (DEC) 46Devon, England 128diesel 92, 94, 144, 174

engines 90, 96generators 56see also biodiesel

diet 96disasters, environmental 10, 14, 22, 38,

170, 202dish Stirling systems 50district heating networks

solar heating in 44–5with woodchip systems 86–7

emissions 86diversion hydroplants 118doping 52Dortmund 124downhole heat exchangers 124droughts 14, 16dry biomass 78–9duel 5 per cent ceiling 182

earthquakes 120economic benefits of renewable energy

38–9Eco-design Directive for Energy using

Products (2005/32/EC) 30Ecological Taxation Reform (ETR, Germany)

142, 168, 170, 200how ETR works 173in increments 174–5protecting jobs and environment 172–3reducing star-up finance for renewable

energy 175

242



economic crisis 8, 10, 18, 20, 152economic growth from renewables 152eco-tax 36, 175ECO-Watt project 216, 217Edison, Thomas 220EEG see Renewable Energy ActEgypt 18, 148electric lighting 220electrical appliances 30, 77electricity

consumption 24, 28, 30, 34, 116how can we store large amounts 156–7

electrolysis 132, 133, 156emissions

carbon see carbon dioxide (CO2)emissions

certificates 196trading 196–7

how it works 197Emissions Trading Directive, 2003 196employment and renewables 162-3Energiewende (energy transition) 28energy

addiction to imports 20–1conservation 32, 36–7, 62, 66, 158–9,

162, 166, 198, 216–18consumption increase in 8, 20, 36reduction of 8, 10, 28, 30, 66, 67–9, 72,

74, 130, 152, 216crops 88–9

dedicated 78potential energy yield 89

density, low 26, 88, 94domestic production 20efficiency 8, 14, 18, 20, 28, 30–1, 38–9,

140, 162, 166, 174, 204fund 37

global consumption 8, 26–7, 122imports 12, 20, 145, 162

market competition 34, 37liberalization of 34–7

payback 160–1policy 12–15, 18, 20, 28, 36, 37, 59,

168, 202, 204

rising prices 35, 175service firms 214–15transition 28, 32, 36, 150, 164, 203, 208yield 48, 60, 70, 88, 89, 94, 110, 112,

178Energy-Autonomous Solar House, Freiburg,

Germany 74, 76Energy Industry Act 1998 (Germany) 208Energy Performance of Buildings Directive

(EU) 62energy-using products (EuP) 30EnBW 34, 164E.ON 34, 164Erding, Bavaria 124ethanol: fuel from plantation 92–3, 94, 95,

148Ettlingen, Germany 213EU (European Union) 20, 88, 96, 142, 154,

162Directive on the Promotion of Electricity

from Renewable Energy Sources 142,144

expanding renewables 146–7growing dependence on energy imports

145votes for renewables 144–5

Europe 16, 50, 122, 132evacuated tube solar collectors 40external costs, internalising 170–1external insulation 72, 76

Factor Four 28family dwellings 178FAQs 154–65farmers 11, 48, 56, 90farms 54, 56, 80, 152

fish 122solar 132wind 98, 100, 110, 164

Feed-in Act 1991 (Germany) 116, 142, 164,182–3, 184, 208

feed-in tariffs (FITs) 11, 12, 37, 38, 50, 54,60, 82, 98, 104, 110, 116, 142, 146,158, 164, 168, 180–92, 198, 200, 201

for heat in Germany? 194–5fertilizer 16, 80, 81, 94, 96

243

Index


fields fuel from: biodiesel 90–1as solar collectors 78–9

financing, start-up 169–9Finland 32, 146firewood 48, 84, 148Fischer-Tropsch synthesis 94fish bypasses 118, 119fish farms 122fish ladders 118fishermen 120flat-plate solar collectors 40

design of 41flex-fuel vehicles (FSV) 92flood(s) 14, 15, 16, 92

protection 118, 120flow rates 118food production 88, 92, 122forests 84, 148

as solar collectors 78–9Forsmark nuclear plant, Sweden 22fossil energy 10, 14, 16, 18, 24–5, 38, 46,

132, 146, 150, 152, 158, 162, 166–8,170, 172, 174, 194, 202, 206

France 108, 126, 128, 146, 186, 190Fraunhöfer Institute for Solar Energy

Systems and Innovation Research (ISA)74, 150, 154, 170, 216

Freiburg, Germany 74, 76, 94, 216Freiburg Energy and Solar Agency 216Friedrichshafen solar heating pilot project

44Friends of the Earth 100fuel cell(s)

cars 138efficiency for domestic power 137how they work 134–5hydrogen-powered 138in mobile applications 138–9service life 13stationary 136–7

fungicides 88Future Energy initiative, North Rhine

Westphalia 218Future Investment Programme 166

gas 10, 20, 24, 29, 34, 64, 74, 81–2, 84,87, 94, 130, 175, 194, 195, 206, 218,219

boilers 86burners 48, 49global reserves 21heaters 11, 42, 86, 131heat-trapping 16, 82imports 20, 84methane 198natural 10, 16, 45, 48, 62, 80, 90–1, 94,

131, 132, 134, 137, 138, 156, 158,172, 174, 207, 214

prices 38turbines 22, 154, 156, 157, 209waste 78

gasoline and ethanol 92Geothermal Association of Germany 124geothermal collector 130geothermal energy 122, 124, 152geothermal worldwide 122–3German Aerospace Centre 50, 150, 154German Association for Landscape

Protection 100German Economic Ministry 170German Energy Agency 178, 200German Energy Research Programme, 5th

166German Federal Network Agency 34, 110German Hydropower Association (BDW) 116German Institute for Economic Research

(DIW) 38German Ministry of Environment 194German Ministry of Research and

Technology 98, 166German Research Framework Programmes

166German Wind Energy Association 112Germany 9–12, 14, 16, 20, 22, 24, 28, 30,

34, 36–8, 50, 54, 60, 62, 68, 70, 72,74, 76, 80, 82, 86, 88, 90, 98, 100,102, 104, 106–8, 110, 112, 116, 120,140, 142, 150, 154, 158, 162, 166,169, 170, 176, 182, 186, 187, 188,190, 192, 194, 200, 203, 206, 216,218

244



federal funding for energy research 167future has already begun in 142–3liberalization of energy market in 34–7long-term scenario for 150–1potential of renewable energy in 140–1

fuels 140heat 140power generation 140

Geyser, the 122glaciers 10, 16Global Status Report 186global warming 16Göttingen, Germany 9grain 79, 88, 89, 92, 114grasses 88, 89Greece 146, 186green electricity 153, 206, 208–9greenhouse effect 16, 158, 170, 202greenhouses 122, 125green hydrogen 132, 138green power from utilities 208–9Greenpeace 100grid-connected PV arrays 54–5groundwater 78, 118, 130 Growian project 98Gunung Salak 122Güssing 252

Hamburg, Germany 192Hamburg-Bramfeld solar heating pilot

project 44Hansen, Meinhard 72harvests 48, 78, 88, 96, 179health

care systems 58clinics 58human 170, 220risks 120, 148

heat storage, long-term 44-5trapping gases 16, 82

heat exchangers, downhole 124‘Heat from the sun’ campaign (Germany)

142heat pumps 130–1

ecological payback 130

how they work 130heatwaves 10, 16Hessen 176HEW 164high-voltage power pylons 100hills, siting wind turbines on 102homes without heaters: passive houses

72–3hot dry rock (HDR): power from

underground 126–7how it works 127

hot water, solar 42–3human health 170, 220100 per cent target 152–3100,000 Roofs Programme 60, 142, 168100,000W Solar Initiative 218Hurricane Katrina 16hurricanes 10, 14, 16hybrid cars 156hydro dams 116hydrogen 74, 91, 132, 134–6, 138–9, 152,

154, 156cars 134green 132, 138renewable 114solar 90, 132–3

hydro geothermal heat plant, how it works125

hydropower 24, 26, 28, 114–29, 132, 140,143, 146, 148–52, 156, 159, 164,165, 184, 185, 198, 201, 207, 209,210

expanding: example of Germany 116–17as largest source of renewable energy

114–15micro- 116, 148and nature conservation 118–19

barriers 118minimum water volume 118

world’s largest plants 120–1hydrothermal systems 124

Iceland 114, 122, 152Iguaçu river 120India 108, 148Indonesia 122

245

Index


industrial buildings 62insecticides 88insolation 12, 26Institute of Applied Ecology, Freiburg,

Germany 28, 29, 162, 202, 208, 216Energy Transition study 28–9, 150

Institute of Economics and Ecology, StGallen College, Switzerland 100

insulation 30, 40–1, 62, 66, 68, 72–6, 159,174

transparent 62, 64, 70–1insurance premiums 170internal sources of heat 72internalising external costs 170–1investment

bonuses for solar thermal systems176–7

in climate protection 216–17return on, as compensation for solar

power 180–1Iran 19Iraq 18Ireland 146, 186, 190Israel 148, 194Itaipú dam 120Italy 108, 122, 146, 148, 186

Japan 92, 122, 144, 148jatropha 96Java 122job market and renewables 162-3Jühnde, Germany: bioenergy village 152

Kuwait 18Kyoto Protocol 196, 198

landlords 178landscape

conservation 101cultural 100and PV arrays 188–9and wind power 100, 102, 112

Lardarillo, Italy 122Latif, Mojib 16Latin America 58, 96Latvia 146

‘Lead Study 2007 – Update andreassessment of the use of renewableenergies in Germany’

liberalization of power market 32, 34–7,164, 182, 184, 202, 208, 218

negative effects on cogeneration 32lighting 28, 56, 216, 218

electric 220solar 220

lignocellulosic plants 88Limits to Growth (Club of Rome) 18liquid hydrogen 132loans 177

low-interest 68, 158, 176, 201Lovins, Amory 28Lovins, Hunter 28low-energy buildings 30, 62low-temperature heat 28, 46, 62, 124lower costs 60–1Lower Saxony, Germany 112

Madrid 192market development 60Market Inventive Programme 192, 194marketing successful projects 206–21mass production, lower costs from 60–1meat production 96medicine 58Mediterranean countries 50Merkel, Angela 194Mesopotamia 114methane 16, 80, 82, 198methanol 94, 134, 136, 138Mexico 18microgrids 58micro-hydropower units 116, 148miscanthus 78, 88, 89models of usage 194modernization, solar thermal and PV in

68–9Mohave Desert, California 50motor fuels 28Municipal Utility of Zürich 212–13Municipal Utility of Ettlingen 214

natural gas 10, 16, 45, 48, 62, 80, 90–1,

246



94, 131, 132, 134, 137, 138, 156,158, 172, 174, 207, 214

nature conservation and hydropower 118–19and wind power 100–1

Netherlands, the 32, 110, 146, 186Neustadt-Glewe 126new energy technologies 130–9

lower costs from 60–1using 220–1

nitrous oxide 16North Africa 50, 132North Rhine Westphalia 218North Sea 102, 110Norway 18, 114nuclear disasters 170, 202nuclear energy 20

external costs 170industry 22not an alternative 22–3peaceful and military uses 22phasing out 202–3

nuclear fuel rods 22

Obama, Barack 108Obrigheim nuclear plant, Germany 22ocean energy 128ocean water evaporation 24off-grid applications, renewables for 204–5off-grid PV arrays 56–7off-grid solar house 62, 74–5

as model for Solar Age 74offshore turbines 110–11oil 24

consumption 18crude 20depletion midpoint 18disasters 170heaters 42imports 20lamps 220peak 18rapeseed 90rising prices 20, 84reserves

global 21

fight for limited 18–19Olmedilla, Spain 54Oman 18Ontario 186OPEC states 18Ö-Quadrat 218organic waste 78, 80Organisation for Economic Co-operation

and Development countries 148orientation 66Osterberg neighborhood, Germany 192oxygen 74, 78, 120, 132, 134, 135

Pakistan 186parabolic trough plants 50Paraguay 120Paraná river 120passive houses 62, 63, 66, 72–3, 76passive solar energy 64–5, 75Paul Robeson School, Leipzig 70Pelamis project 128Persian Gulf 18Peru 148Philippines 122photovoltaics 52–61, 76, 77, 83, 114,

140–3, 146, 148–51, 154, 158, 159,161, 165, 166, 168, 180, 181, 184,185, 201, 216

concentrator systems 60advanced designs 60outlook for 60–1thinner cells 60see also PV arrays

plantations 11, 78, 88, 89, 90, 96fuel from: ethanol 92–3

plus-energy houses 76–7policy instruments 104, 186, 194, 196,

200–1, 204pollution 42, 46, 86, 138

air 38soil 78

Portugal 146, 186power monopolies 164–5predatory pricing 34, 36, 136, 164Prenzlau, former East Germany 124PreussenElektra 164

247

Index


PROÁLCOOL Program 92Prognos 169promoting renewable energy 166–205public support for renewables 206–7public transport 56, 138pumped storage plants 156pumps 64, 116, 122, 216

efficient 30heat 130–1

PV (photovoltaic) arrays 52–3as ‘blight’ on landscape 188–9grid-connected 54–5off-grid PV 56–7in renovation 68–9siting and site restrictions 88

pylons, high-voltage power 100

quotas and requests for proposals 190–1

radio 56radioactive waste 22, 166, 171rain 12, 24, 48

acid 170rainforest 96Rance, river 128rapeseed 11, 78, 79, 90, 93, 94, 152, 153RAVEL programme 200reforestation 198refrigeration, solar 46–7refrigerators 130renewable energy 36–7

economic benefits 38–9and job market 162-3facts 36–7as future option 24–5for off-grid applications 205other possible sources 128–9promoting 166–205public support for 206–7in Third World 204–5worldwide 148–9

Renewable Energy Act, Germany (EEG) 60,82, 112, 142, 164, 168, 170, 182–5,194, 204, 218

as model for other countries 186–7renewable hydrogen 114

renovation, solar thermal and PV in 68–9example 68

rental apartments, solar energy in 178–9Repower 108repowering 112–13requests for proposals and quotas 190–1research funding 166–7Rheinfelden plant 116, 120Rhiel, Alois 34Rhine, river 124, 126 Robin Wood 100Roman Empire 114rural electrification 58RWE 34, 164

Sahara 26, 50St Malo, France 128Saudi Arabia 18Scandinavia 156schools 56, 58, 72, 218Schroeder, Gerhard 202sea, power from 128Seaflow 128, 129semi-conductors 60service, energy 214–15Seville 192shading 66Shell 56, 94silicon solar cell 52–4Simbach-Braunau, Bavaria 124siting and and site restrictions for PV arrays

188Slovakia 22social impact of hydropower plants 120soil 88, 90, 94, 96, 100, 188

pollution 78Solar Age 10, 12, 24, 25, 30, 31, 62, 64,

66, 74, 75, 104, 138, 150, 152, 168,192, 202, 216

as end of power monopolies 164–5solar air-conditioning 46solar architecture 62–77solar arrays 10, 26, 54, 84, 148, 160, 178,

182, 184, 188, 206, 214, 216, 218community 210–12as component of renovation 69

248



required on new buildings 192–3solar bonuses 176solar brokers 212–13solar cell 52–5, 133, 142, 160, 188

how it works 52thinner 60

solar chimneys 128–9solar circuit 42solar collectors 30, 40–1, 42, 46, 48, 50,

75, 151, 192design of flat-plate 41fields and forests as 78–9

solar drying with air collectors 48-9solar electrification programme for schools

58solar electric: photovoltaics 52–61solar energy 8, 10, 12, 24, 26–8, 30, 36,

42, 44, 46, 48, 52, 62, 66, 68, 69,72–6, 78, 82, 90, 114, 133, 134, 140,150, 154, 171, 180, 186, 192, 204,206, 207, 214, 216, 217, 220

as part of sustainable development 58–9passive 64–5in rental apartments 178–9

Solar Energy Association, Aachen 180Solar Estate, Freiburg, Germany 74, 76solar farms 132solar future, scenario for 28–9solar heating 179, 206

in district heating networks 44–5‘Solar heat plus’ campaign (Germany) 142Solar Home Systems 56, 58, 204, 206, 220solar hot water 42–3

decisive benefit 42example 42technology 42

solar hydrogen 90, 132–3solar lamps 221solar lighting 220solar optimisation of urban planning 66–7Solar Ordinance, Barcelona 192solar panels 30, 54, 60, 76, 142, 171, 188solar power 8, 10, 24, 26–7, 46, 48, 50, 54,

58–60, 76, 82, 132, 142, 148, 150,156,158, 164, 169, 178, 180–2, 184, 186,188, 190, 209, 211, 212, 218, 220

benefits of 26and conservation 30–2

Solar Power Exchange 212‘Solar power – now’s the hour’ campaign

(Germany) 142solar refrigeration 46–7solar roofs 26solar thermal arrays required on new

buildings 192–3Solar Thermal Ordinance, Berlin, 1995 178solar thermal systems 24, 40–51investment bonuses for 176–7

with long-term heat storage 45power plants 50–1in renovation 68–9

solar tower plants 50solar tunnel dryers 48Soultzsous-Forêts, France 126South America 114southern Europe 146space heating 30, 42, 44, 46, 48, 62–3, 69,

74, 77, 140comparison of key energy figures in

various building standards 63Spain 108, 128, 146, 148, 178, 186, 190,

192, 194standby power consumption 30start-up financing 169–9Staudinger School 216Stern, Sir Nichola 170storage of large amounts of electricity 156–7storms 102Straubing, Bavaria 124straw 78–80, 90, 94, subsidies 22, 38, 44, 56, 92, 148, 168,

172, 198, 204annual, in energy sector 169

subterranean storage tanks 44sugar beets 92, 93, sugarcane 88, 92, 93, sun 24–6

solar energy, benefits of 26Sundiesel 94sunfuel 94sunlight 16, 24, 26, 40, 48, 50, 52, 56, 64,

70, 74, 78, 124, 160

249

Index


sustainable development 198, 204solar energy as part of 58–9sustainable energy 10, 13, 15, 20, 24, 37,

38, 59, 100, 122, 162, 198, 202, 204,208, 216

Suzlon 108Swabia 126swamps 92Sweden 22, 44, 84, 90, 110, 146swimming pools 40, 122, 192, 206Switzerland 84, 114, 156, 200, 212synfuel 94synthetic fuels (BTL) 94–5

taxation 34, 36–7, 90, 92, 142, 164, 168,169, 170, 172–5, 194, 196, 200, 218

see also Ecological Taxation ReformTechnorama, Dortmund 124telephones 56television 56temperature

global increase 8, 10, 16, 17low-temperature heat 28, 46, 62, 124

tenants, solar energy for 178–9terrorism 22Thailand 186Third World, nuclear energy in 204–5Three Gorges Dam 120–1tidal power plant 128toxic emissions 84, 87, 172traditional biomass 148transparent insulation 62, 64, 70–1transport sector 90trees 64, 84, 88, 188triple glazing 64, 72‘250MW Wind’ programme 98typhoons 15, 16

UAE (United Arab Emirates) 18UK (United Kingdom) 18, 22, 108, 110,

146, 186, 190UN Conference on the Environment and

Development, 1992, Rio de Janeiro 166underground heat 124–5, 130underground power: hot dry rock (HDR)

126–7

University of Kassel 152uranium reserves 22urban planning, solar optimisation of 66–7,

192US (United States) 18, 92, 104, 106, 108,

144, 148usage, models of 194utilities 32, 36–7, 164, 180, 182, 214

green power from 208–9utilizing new leeway 218–19

Vattenfall 34, 164VEAG 164VEBA 164Vellmar, Germany 192Venezuela 18ventilation 30, 52, 73, 77, 216

regulated 72, 74, 75systems 48, 62, 72, 76

ventilators 48Vermont 186VEW 164VIAG 164‘visual emissions’ 100volcanoes 122, 124Volkswagen (VW) 94, 138

wall as heater: transparent insulation 70–1energy yield 70how it works 70rule of thumb 70

Waren, former East Germany 124waste disposal 24water 8, 14, 16, 24, 29, 46, 78, 88, 110,

111, 116, 118, 120, 124, 128, 132,134, 156, 217

conservation 216–17heaters 154hot 30, 40–1, 44–5, 50, 63, 69, 74,

76–7, 81, 85, 126, 130, 148–9, 179,192, 214from sun 42–3

management 118mills 114power see hydropowervapour 135, 138

250



waste 80weather changes 24Weizsäcker, Ulrich von 28wet biomass 78white light emitting diodes (LEDs) 220White Paper for Strategy and Action Plan

for renewables (EU) 144Willibrord School, Emmerich 218, 219wind farms 98, 100, 110, 164wind power 24, 26, 28, 98–113

jobs in 163and nature conservation 100–1prospects

less is more through repowering112–13offshore turbines 110–11

success story ofadvantage of being first 106–7since 1990s 104–5

worldwide108–9

wind turbines 98–9wind velocity 102–3windows 64–5wood 78

as energy source 84–5pellets 84

wood-fired heating systems 84wood stoves 84, 86–7World Wide Fund for Nature 100Wuppertal Institute 150, 218

Yangtze river 120

zero-energy buildings 62Zürich 212–13

251

Index


renewable energy - the facts

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