mastering future challenges with gas innovations

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Mastering future challenges with gas innovationsIntelligent technologies for the energy transition

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Our project partners

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With the energy transition, Germany has opted for a fundamental transfor-mation of its energy system. Produc-tion, transport and demand structures face a comprehensive modification which will have an impact on all sectors of energy consumption. In the transformation of the energy system, gas is the key resource for integrat-ing renewable sources of energy – it is safe, flexible, highly efficient and especially climate-friendly. Further-more, Germany already has a safe, high-performance gas infrastructure.

Up until 2050, the share of renewables in the German power supply is to be gradually increased to 80 percent. To meet the ambitious climate protection and CO

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emissions targets of Germany and Europe, much still remains to be done. On the one hand, power grids will need to be mod-ernized and expanded. On the other hand, additional storage capacity and system services will be required in order to compensate for fluctuations in wind and solar power.

One thing is clear: the German economy can only function smoothly with reliable

energy sources that are continuously avail-able. Of all the fossil fuels, natural gas has the best climate balance. In addition, there is still considerable untapped efficiency potential in the optimized utilization of nat-ural gas. Combined-cycle power stations with gas and steam turbines are already the ideal complement to volatile, renew-able energy sources thanks to their high efficiency and flexibility. Gas-fired power stations allow rapid changes in output, generating power in an extremely flexible way and achieving continuous high energy efficiency.

Gas is also very well suited for combined heat and power (cogeneration), as well as the simultaneous, coupled use of elec-tricity and heat in the power generation process. In the heat market, the combi-nation of condensing natural gas boilers with renewables and cogeneration offers further advantages. For example, ad-vanced natural gas heating systems with condensing boilers may be combined with solar heating systems, significantly reduc-ing climate damaging CO

2 emissions in

comparison to older systems. Furthermore, natural gas and biomethane can make a key contribution to climate protection and

energy efficiency when used as motor vehicle fuels.

The new technical challenges posed by the energy transition will create additional opportunities for the use of gas infra-structure – for example, the storage and transport of large quantities of energy resulting from surplus power generation from renewable sources. If surplus power from wind or solar power systems is used for electrolysis to produce hydrogen and oxygen, the hydrogen can either be fed directly to the gas grid or converted into methane in a second process step.

The conversion of power into a fuel (power-to-gas) can relieve the burden on the power grid and reduce the need for the expansion of the power grid. Energy is transported by gas grids and can therefore be made available to 40 million people and a variety of stationary and mobile appli-cations in Germany. Power-to-gas covers the entire range of efficient gas utilization technologies – from the traditional heating market power generation, including heat and power cogeneration, to climate-friend-ly mobility and the use of gas as a feedstock in the chemical industry. Further

Gas – the key to success for the energy transition!


opportunities can be developed from the liquefaction of natural gas (LNG = liquefied natural gas). LNG can also be used for powering heavy trucks and ships.

Within the framework of the energy policy system defined by climate protection, security of supplies and economics, gas can play a key role in reshaping the energy supply in Germany. The utilization of ex-isting gas infrastructure offers good pros-pects for an environmentally and economi-cally beneficial combination of predictable, safe natural gas supply and volatile power

supply from renewable sources. The gas of the future will not only include natural gas from fossil sources, but also biogas and other renewable gases.

This evolution will not be possible without technological innovations within the gas system. Apart from technical safety, the main emphasis will be on optimizing the energy efficiency of individual components and on the entire gas processing and utilization chain. This extended role that natural gas can assume within the energy system will require early stage technical

and scientific preparations. Since 2009, DVGW has worked intensively in this area within the framework of its innovation campaign. Together with a large number of member companies, the association has now invested almost € 10 million in research with the intent of improving the technological potential of gas. This bro-chure presents brief and concise informa-tion on the main results of this work.

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Redefining the role of gas Page 6

The DVGW innovation campaign Page 12

Research clusters Gas in an integrated energy system Page 14Smart grids Page 18Power-to-gas Page 21Gas production and upgrading Page 24Cogeneration and utilization technologies Page 28

Project overview Page 32Publication details Page 35


Contents

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Redefining the role of gasBackground

Redefining the role of gas

Over the past three years, the issues raised by the energy transition have been the key topic of discussion in the energy industry. As this unique infrastructure project progressed, one thing became clear to all the players involved. The implementation of the energy transition will pose many technical, economic and social policy challenges.

The growing dominance of renewables in power generation has given rise to entirely new questions with respect to the energy industry’s priorities of economic viability, sustainability and security of supply. New approaches will be needed to make the integration of renewable energy sources economically viable and technically reliable. In heat generation, innovative technology is needed to make a contribution to energy efficiency, with the intent of reaching climate protection targets. New vehicle concepts are

also necessary to reduce the environmental impact of carbon dioxide and fine particulate matter. Finally, technologies will need to be developed to compensate for fluctuations in power generation from renewable sourc-es over longer periods of time. Within the overall structure of the energy transition, it is becoming increasingly clear that the isolated optimization of individual stages in the energy supply chain will not be suffi-cient. With reference to the entire energy system and the aim of the energy industry,

systematic thinking beyond the boundaries of power and gas will be needed. With respect to technology, DVGW has been shouldering the challenges posed with regard to energy storage, energy efficiency and the integration of renewables in its gas innovation campaign since mid-2009. With its infrastructure which is proven and already available, gas can provide effective solutions to many challenges posed by the energy transition. Moreover, the results of research carried out within the DVGW gas innovation campaign

“The energy transition is a long-term project for the decarboni-zation of our energy industry with goals, many of which are in the distant future. This means that the various options must be

assessed in a way which is neutral to the use of technologies and considers different systems. Security of supply and economics are top priorities. On this basis, gas will play a key role in the energy

transition with its existing infrastructure systems.”

Michael Riechel, Member of the Board of Management of Thüga Aktiengesellschaft, Munich, Vice-President of DVGW, Chairperson of the DVGW Gas Research Advisory Council

Transport and distribution

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show that gas and gas infrastructure have the potential to play a major role in an energy system based on renewable sources in the long term. However, this will mean that both the system and the role of gas will need to be redefined.

From mono-gas to multi-gas

The time when natural gas could be consid-ered as purely a fossil fuel is now long gone. Germany is a world leader in the injection of upgraded biogas (also referred to as biom-ethane or bio-natural gas) into natural gas grids. 140 plants are now feeding biogas into the German natural gas grid. In 2006, there were only two plants of this kind in Germany. Over the past year, there has also been a significant progression in the production and injection of hydrogen or methane produced using power from renewable sources (power-to-gas) over the past year. While the first pro-ject of this type mainly focused on hydrogen

generation for mobility applications, this technology entered the field of gas supply with the transport and distribution infrastruc-ture last year. In 2012, the first power-to-gas plants were connected to the gas grid. Currently, a total of 18 power-to-gas plants are either connected to the gas grid or under construction in Germany. Six more projects are either in the planning stage or have been awarded subsidies for implementation.

Greening of gas

The benefits of the “greening of gas” are evident. Since existing natural gas infrastruc-ture is utilized, it is possible for power to be generated and used at different times and places. Decentralization of power generation is not the only result of the generation of power from renewable sources. Another aspect needs to be considered; renewable energy sources such as wind and sunlight are not available at all times. However, power users, irrespective of whether they are

private consumers or industrial companies, cannot base their use of energy on current weather conditions or the time of the day. They need reliable and continuous power and heat supplies on a round-the-clock basis. Furthermore, it is now expected that significantly more than 100 GW of genera-tion capacity, mainly based on wind power and photovoltaic systems, will be installed in Germany by 2020, in addition to the existing fleet of power stations. Since average power demand in Germany is only between 40 and 70 GW, the power fed to the grid from wind and solar systems will be exceed actual demand far more often than is currently the case. As a result, conventional power plants will be shut down and wind turbines and solar systems will be disconnected from the grid, with the well-known effects on power prices. In economic terms, this approach is anything but “sustainable”. System services to stabilize power grids and appropriate long-term and seasonal storage facilities will therefore be indispensable for a future ener-gy system based on wind and solar power.

x Biomethane

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Use of gas infrastruc-ture for energy storage

The storage potential that is so urgently needed for the further expansion of re-newable energy sources is offered by the German gas infrastructure. With 21 porous rock and 29 cavern storage facilities where 22.7 billion cubic metres of gas can be stored for any required length of time, Germany has the world’s fourth-largest gas storage infrastructure. If the pipeline grid, with a total length of about 500,000 kilometres, is also considered, the storage potential of the natural gas infrastructure compared with other storage technologies becomes very evident. If the two sectors of gas and electric power converge, with power-to-gas as a possible connecting ele-ment, this may be the key to the integra-tion of renewables. A study by the Potsdam Institute for Climate Impact Research (PIK)

has shown that power-to-gas may help protect the climate and limit costs if a functioning CO

2 certificate trading system

is established.

Energy storage and transport

Today, the gas grid already carries about 1,000 billion kWh of energy per year, almost twice as much as the power grid (approx. 540 billion kWh/a). In the future, it is also expected that capacity within the gas

grid may become available. This capacity could be used to store local temporary pow-er surpluses in the form of a gaseous fuel which could then be transported and used for heat generation, mobility, power genera-tion or as a feedstock, in line with demand. New areas of research have opened up in connection with the assessment of the gas grid for long-distance energy transport. Our existing power grids are not designed for the changing requirements resulting from increasingly decentralized power feeding. Power grids will therefore need to be modified and expanded. This applies both

Methanation D Electrolysis D

“Power-to-gas can help in mastering the two central challenges posed by the energy transition: the integration of wind and

solar power and climate protection in the heating and transport sector. Power-to-gas is therefore a system technology that should

be assessed on a long-term basis.”

Prof. Dr. Ottmar Edenhofer, Deputy Director of the Potsdam Institute for Climate Impact Research (PIK)

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D Combined cycle power plant and compact cogeneration

Power-to-gas


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at the transmission level (very high voltage) and at the distribution level (high, medium and low voltage). However, the expansion of power transmission and distribution grid is proving to be extremely difficult, not only as a result of problems with public acceptance. According to a study carried out by the German Energy Agency (dena), up to € 42.5 billion in investments will be needed by 2030 in the power distribution grid alone.

Discussions concerning the cost of the en-ergy transition offer many potential causes for conflicts and also indicate the need for comprehensive research. Research findings from the DVGW innovation campaign show that the use of power-to-gas could even reduce expansion requirements at the dis-tribution grid level, resulting in a reduction in the overall cost.

Efficient generation of power and heat with gas

Power-to-gas technology is not the only im-portant connecting element between power and gas grids. Gas-fired cogeneration plants such as mini-CHP plants allow flexible con-trol and can make an essential contribution to maintaining power grid stability. Thanks to the simultaneous generation of heat and power, they also help reduce energy consumption and CO

2 emissions.

According to a study carried out as part of the DVGW innovation campaign, the ambitious climate protection targets of the German government can be achieved by the increased use of gas-based cogeneration

technology in buildings. This is especially the case if low-emission, renewable fuels such as biogas, biomethane, hydrogen from renewable sources and synthesis gas from power-to-gas plants are used.

Cogeneration also opens up new approach-es. Since cogeneration involves the use of waste heat in addition to power generation, it allows insulation work on buildings to be minimized or optimized, reaching the same CO

2 targets at a significantly lower cost.

However, this is by no means the only benefit of cogeneration.

Development work will need to continue on high-efficiency cogeneration technologies at all output rating ranges. Smart approaches to waste heat utilization, not only for heating or hot water preparation but also for air con-ditioning, for example, can further improve the efficiency of cogeneration systems.

D Industry and commercex Underground gas storage

“Interdisciplinary analysis of the energy system and the combinations which are possible within an integrated

system are laying the foundation for unconventional approaches. Only within this context can environmental projects that are

economically viable actually be feasible.”

Dr. Jürgen Lenz, Vice-President of DVGW, and (2003–2013)

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Mobile with gas

Currently, there are about 96,000 natural gas vehicles on German roads and about 900 natural gas refuelling stations. Every year these vehicles save about 323,000 t of CO

2, which damages the climate. The in-

creasing admixture of biomethane to natu-ral gas will further improve the CO

2 balance

of natural gas vehicles. A new incentive for gas mobility has been provided by the Audi eGas project. Since the beginning of 2014, a 6 MW power-to-gas plant consisting of an electrolysis unit and a methanation unit has been operated in Werlte, Germany.

The hydrogen produced by electrolysis is converted into methane in the methanation unit together with carbon dioxide from a nearby biogas plant and then injected into the gas grid. The power-to-gas and biogas plants feed gas into the same grid and

therefore make the gas produced availa-ble throughout practically all of Germany. Also in Europe, the role of gas in mobility is currently being reassessed. The EU Commission sees gas as a key element in its strategy for the development of alterna-tive fuels.

The EU Commission has also announced that LNG infrastructure is to be developed along key European highways. LNG will

also have an increased use in shipping. In research and development projects, the use of LNG in coastal and inland shipping is currently being investigated. The main focus is on major European inland water-ways such as the Rhine; investigations will include both ship engine systems and land infrastructure.

L Micro-cogeneration, fuel cell

D Natural gas condensing, solar, gas fuelled heat pump

“In the heating market, we are still at a very early stage in the energy transition. The main focus in a “heating transition” based on effective climate protection must be on CO2 avoidance costs. How can CO2 emissions be avoided at the lowest cost possible?

Here, natural gas is a key player.”

Dr. Ludwig Möhring, President of ASUE and Member of the Board of Management of the WINGAS Group

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No energy transition without gas

Political discussions focus on the challenges posed by a reliable, affordable, stable electric power supply. However, an affordable energy transition with stable systems will only be possible through cooperation between the power and gas industries.

The highly flexible gas system and innovative gas technologies can offer solutions that significantly reduce the total cost of transfor-mation while simultaneously complying with CO

2 targets and also considerably improving

system stability, especially the stability of the power system.

For this reason, gas and gas infrastructure should be given considerably more attention in political and technical discussions than has previously been the case.

“A comparison of energy transmission costs for power and gas systems should be enough to attract the interest of

everyone in the energy industry. At a cost of about 1 million per kilometre, you can build a natural gas pipeline with a transmission capacity of 20 –30 gigawatts. If you consider a power system, an overhead 380 kV line could only carry

about 2 x 2 GWA i.e. a total of about 4 GW.”

Prof. Dr. Albert Moser, Head of Institute of Power Systems and Power Economics, RWTH Aachen University

L Natural gas as a motor fuel

“The commenced transformation of the energy supply poses a major challenge for engineering ingenuity. We need to consid-er the entire innovation chain from basic research up through

industrial technology. Natural gas will create a solution that can guide the energy transitions through to success.”

Prof. Dr. Robert Schlögl, Director, Fritz Haber Institute of the Max Planck Society, Berlin

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Research clusters of the gas innovation campaign

Within the framework of its innovation campaign launched in 2009, DVGW is investigating gas technologies to make future energy systems safer, more efficient and more environ-mentally compatible in cooperation with companies from the German gas industry, research institutes and manufacturers. The campaign includes about 30 different projects, which were grouped together by topic into thematic research clusters:

Gas in an integrated energy system System analyses covering the role of gas in a future energy system with a variety of in-novative technologies have been conducted.

Key topics:l Assessment of the process chains of various fuels considering energy, environmental and economic aspects

l Classification of natural gas as a fuel with reference to existing energy policy conditions

l Preparation of a gas-based scenario for achieving climate protection goals with significant economic benefits

l Potential of cogeneration in combina-tion with intelligent waste heat utilization

Smart gridsWork in this cluster is concentrated on the increasingly complex requirements for the design and operation of future distribution grids. Topics covered have included the expansion of decentralized biomethane injection plants, growing requirements for dispatching, the creation of high-perfor-mance IT infrastructure for grid operation and the synergy potential between the gas and power infrastructure.

Key topics:l Preparation of a concept for an intelli-gent, networked gas distribution grid

l Development of a biogas potential atlas that not only determines the quanti-ties of biogas which can be produced considering sustainability and water protection criteria, but also links these potentials with optimum locations in the gas grid

l Identification of the potential of power-to-gas at the distribution grid level on the basis of a specific case study with the intent of minimizing the expansion of a real power grid

Power-to-gasPower-to-gas technology establishes the link between power and gas systems. The specific benefits of the two systems within the overall energy supply system are mutu-ally complementary.

Key topics:l Investigation and verification of the hydrogen compatibility of the gas infrastructure

l Investigations of metering and invoicing matters in connection with hydrogen/natural gas mixtures in the gas grid

l Further development of methanation processes and optimization of efficiency

l Investigation of innovative (biological and catalytic) methanation processes

l Standardization of the design of power-to-gas facilities

l Viability analyses of power-to-gas in the energy system

Electrolysis is a key technology in the power-to-gas field. It has been possible to significantly improve the functionality and efficiency of electrolysis systems. The objective is to promote the transfer of this technology, which has been used with considerable success in the chemical industry for many years, to the energy industry.

The DVGW gas innovation campaign

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Gas production and upgradingBiogas has now become established as a renewable source of energy. A number of different gas production and upgrad-ing processes have been developed and implemented in practice. Thermochemical biogas production is another option for the utilization of biomass in biogas production that is currently being investigated.

Key topics:l Investigations to optimize gaseous fuel production processes

l Expansion of the raw material spectrum, especially in regards to biogenic waste

l Optimization of process chains for gas production, upgrading and injection with respect to energy efficiency and environ-mental and economic factors

The initial work focused on biomass as a renewable energy source. Later, the studies also covered wind and photovoltaic power.

Cogeneration and utilization technologiesThe objective of this research cluster was to identify the efficiency potentials of innova-tive gas utilization technologies in combina-tion with renewable components.

Key topics:l Investigation of various concepts for the integration of solar heating on the basis of established condensing boiler technology in various segments of the heating sector

l Efficiency potentials of gas-fuelled heat pumps

l Potential of cogeneration and fuel cells, which have reached electrical efficiencies of up to 60 per cent in long-term trials

l Effects of changes in gas composition on thermal processes and industry

l Behaviour of existing gas appliances operating with hydrogen/natural gas mixtures (field tests)

Demonstration centres featuring these innovative gas technologies are available for information and education purposes at various facilities of the research institutes concerned.

Communication and cooperationThroughout the course of the innovation campaign, communications with politi-cians, associations and other organizations in the energy and utility industries have intensified. In addition, new interdiscipli-nary cooperation arrangements have been established, for example with the hydrogen and chemical industries and with scientific institutes working in climate research and systems analysis.

Political discussions have reinforced the importance of gas, initially in research, for example by establishing energy storage research centres. It is now possible to include the specific benefits of gas in terms of climate protection, efficiency and economics, also with respect to mobility, in a number of political initiatives.

In the scenarios of the energy concept adopted in 2010, the objective was that gas should be eliminated from energy systems in the medium-term future. This energy policy objective has now been adjusted to a future-oriented direction.

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Research clusterGas in an integrated energy system

The research cluster “Gas in an inte-grated energy system” is assessing the role of innovative gas technologies with respect to the challenges posed by growing energy efficiency, reducing greenhouse gas emissions and the pro-jected cost of climate protection. The objective is to develop an overall analy-sis of energy supply chains against the backdrop of system stability despite increasingly volatile power generation from renewable sources.

At the beginning of work on this research cluster, it was already apparent that affordable, reliable, low- CO

2 energy

supplies would call for comprehensive cooperation between gas and power grids, which had previously been largely operat-ed as separate systems.

This research work is being carried out against the backdrop of an energy transition based largely on renewable energy sources. The studies carried out investigated the complementary proper-ties of gas within a cost-optimized overall energy system with the intent of devel-oping sustainable overall solutions. The main focus was on the systems analysis of energy supply chains, and especially on gaseous fuels carried by pipelines. The main assessment criteria used included energy efficiency, CO

2 emissions, security

of supply, the integration of renewables and economic aspects.

The main focuses included:

l Determination of the potential for reducing greenhouse gas emissions through the use of highly efficient innovative gas technologies and the integration of renewable energy sources

l Energy industry and macroeconomic assessment of energy supply chains up to household consumers, paying special at-tention to gas as a primary energy source

l Convergence potential of power-based and gas-based energy systems, especially with reference to compensation for the volatility of wind and solar power. The main focus is on the conversion of surplus

power from renewable sources into a storable chemical fuel (power-to-gas) and efficient power generation with smart waste heat utilization through cogeneration (decentralized generation)

l The efficient control of increasingly complex and decentralized structures with intelligent communication technologies

l The assessment of gas-based cogeneration for use in meeting residual loads (not covered by wind and solar power) in combination with the optimization potential of the building sector


l Quelle:l Fig. 1, source: Assessment of the energy supply with gases fuels carried by pipeline compared with other fuels, part II – Effects of advanced gas technologies in the domestic energy supply on efficiency and the environment; systems analysis, part II

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Convergence of power and gas systems

While power generation from renewable sources is subject to increasing fluctua-tions and is not linked to power demand, the gas system is flexible and predictable and can also perform additional storage functions. With respect to transportation, distribution and large-scale storage, the power infrastructure is not adapted to the new generation and distribution require-ments. Therefore, the power infrastructure will need to be expanded while the gas infrastructure is already available and offers capacity reserves. This means that gas can be used to supply energy in order to meet demand at any time.

The assessment of gas as an energy source including advanced gas technolo-gies in comparison with the solutions for the building sector stated in the energy concept from the German government has confirmed this potential. With respect to the measures stated in the energy concept for the building sector and hot water preparation in private households, a study was conducted to investigate whether alternatives are available which would allow comparable emission reductions at a possibly lower cost. A number of different scenarios were investigated.

The “energy concept” scenario is based on the 2010 energy concept from the German government, which focuses on massive building insulation and a higher share of electric power-based heating. The “gas innovation campaign” scenario is based on a growing share of renewable gas in the system, the increased use of highly efficient gas utilization technologies

including cogeneration in buildings and the optimization of building insulation. In contrast, the basic “trend” scenario is based on the assumption that CO

2 savings

measures in the household energy supply will continue at the current intensity; this would mean that the CO

2 reduction targets

for 2050 would not be met.

CO2 reduction potential of gas

However, a comparison of the two scenarios showed that the total capital and energy costs of the “energy concept” scenario, with its strong emphasis on insu-lation, are significantly higher than with the “gas innovation campaign” scenario, which focuses on the increased use of

efficient cogeneration technology (Fig. 1). The cost difference would amount to about € 55 billion by 2050.

The key element in this cost difference is the cost of the relatively expensive insulation work, which will mainly need to be carried out outside of the normal renovation cycle. The savings in terms of energy costs will be far from sufficient to compensate for the higher capital expenditure. All in all, the specific emission avoidance cost with the “gas innovation campaign” scenario is about € 30/t CO

2,

compared with about € 120 t CO2, with the

“energy concept” scenario.

l Fig. 2, source: Synergy effects of gas and power grids – utilization of gas grids and storage facilities for the integration of power from renewable sources, relieving the burden on power grids

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Power-to-gas as a key technology

Another study confirmed that chemical energy storage is the only option for the long-term storage of renewable energies in large quantities and at high ratings so that the energy required can be provid-ed in line with demand. Power-to-gas technology will play a key role because it converts excess power into a substance, hydrogen, which can be used as a source of energy. The viability of power-to-gas technology will depend on the size, loca-tion and configuration of the plants con-cerned as well as the mode of operation and the specific cost of electrolysis. In the projection made for a future scenario, pro-duction costs well below 10 (euro)cents/kWh were calculated for large plants with high capacity deployment. This figure does not include the cost avoided as a result of the reduced expansion of power grids. The studies carried out in this research cluster have shifted the emphasis away from the analysis of power-to-gas purely as a power storage technology. They describe the specific benefits of power-to-gas as an interface between a volatile power system based on renewables and flexible gas infrastructure (Fig. 2).

Power-to-gas can limit the expansion of power systems

In Germany, there is an urgent need for the expansion of the power grid and, in the medium to long term, also for seasonal storage capacities to accommodate the new power generation conditions defined for the energy transition (Fig. 3). The gas pipeline systems and storage facilities available represent a highly promising option for solving this problem.

In a study, selected regions were investi-gated with respect to the expected surplus power, network expansion requirements and the use of power-to-gas technology to carry energy via the gas grid. The study fo-cused on high-wind areas in the northern and eastern parts of Germany. The case study specifically considered the north-south transport of hydrogen produced by power-to-gas via the existing gas grid. It can be demonstrated that the capacities of the gas pipeline system and gas storage facilities are generally sufficient to accom-modate the hydrogen required.

With the storage and pipeline parameters assumed, the transport of surplus energy quantities from the region concerned would still be possible in 2020. The exit capacities available in the south of the

country would be sufficient to make avail-able energy equivalent to that which could not be carried by the power grid.

l Fig. 3, source: Wuppertal Institute on the basis of Federal Environment Ministry keynote study, 2010


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Injection of hydrogen into the natural gas system – the object of further studies

Apart from methanation, power-to-gas also offers the option of mixing hydrogen directly with natural gas. For this purpose, comprehensive studies were carried out concerning the compatibility of compo-nents currently installed the in gas grid with hydrogen/natural gas mixtures. Thus, the current natural gas infrastructure is suitable for hydrogen concentrations in the single-digit range, measured in percent by volume. However, further studies are needed concerning key elements such as natural gas storage facilities, gas turbines and the tanks of natural gas vehicles. In-depth studies and scientific research on the questions which still remain open are

currently being carried out as follow-up projects within the framework of the DVGW gas innovation campaign and within European research networks.

At the macroeconomic level, the Potsdam Institute for Climate Impact Research has investigated whether and under what conditions power-to-gas technology can be successful in economic competition with other CO

2 avoidance technologies. In

the overall economic model, power-to-gas is added to a system of about 70 energy conversion and utilization units as well as CO

2 avoidance technologies in line with the

expected technical and economic param-eters. The computer model optimizes the overall cost required for achieving a CO

2

reduction of 80 percent from the economic point of view.

Power-to-gas versus CCS

The results of the study for power-to-gas are positive if CCS is excluded as a CO

2

reduction option, which would appear to be probable on the basis of the politi-cal decisions made. Depending on the individual scenario, hydrogen injection will grow from about 2020 onwards, reaching the mixture limits currently discussed by 2050, with an electrolysis output of about 50 GW (Fig. 4). From a certain output onwards, it will then be beneficial to meth-anize hydrogen from hydrogen storage facilities in a base load operation.

This approach would result in optimized plant sizes and costs for methanation and the additional cost of methanation from 2020 onwards would be less than 2 (euro)cents/kWh. Based on f these calculations, power-to-gas would result in a reduction of 15–20 percent in the price of CO

2

certificates without power-to-gas. As an-other key aspect, the possibility of making renewable fuels accessible to previously inaccessible sectors such as transport and heating is also emphasized.

It is not necessary to underline the fact that a gas supply system still in existence after the year 2050 would require signif-icant injection of gases from renewable sources.

l Fig. 4, source: Analysis of climate protection potential of renewable hydrogen and methane

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The smart grids research cluster investigates options for the integration of gas and power grids in an optimum way from the technical and economic point of view as a key element in an efficient, secure, sustainable energy infrastructure. In order to implement the energy transition successfully and to react flexibly to the injection of renewable energy, Germany needs adapted infrastructure.

Apart from linking renewable energy sources with energy infrastructure (gas, power and filling station grids), the solution of the power storage problem is the key to the energy transition. Through close connections between gas and power grids, customers in Germany will be able to receive renewable energies with the high degree of reliability to which they have become accustomed. At the same time, power-to-gas technology can provide access to a long-term storage option and help reduce the need for expansion of the power grid.

The German gas grid, with 500,000 kilometres of high-quality pipelines, carries about 1,000 billion kilowatt-hours of gas, about double the quantity of energy carried by the German power grid, about 540 billion kilowatt-hours. If the storage capacity available for natural gas, about 230 billion kilowatt-hours, is also consid-ered, the tremendous potential offered by the natural gas pipeline system as a storage medium for renewable energies becomes evident.

Research work within the smart grids clus-ter has therefore focused on the injection potential for gases from renewable sources (methane and hydrogen) and on load man-agement possibilities (e.g. using dual-fuel capabilities on the gas side to relieve the burden on power distribution grids).

Apart from considering smart grids, in the sense of closer links between power and gas grids, this research cluster has also dealt with the integration possibilities of biogas. A study has been prepared consid-ering the potential of biogas with reference to soil and groundwater conditions as well

as aspects such as the sustainability of energy crop production, the use of digest-er residues and the potential for injection into gas grids.

Road map for smart gas grids

A key research project considered the requirements for smart gas grids and de-scribed three main areas where action is required: grid operation, load shifting from the power to the gas grid and energy stor-age. In these three areas, smart elements that will provide the functions required in the future (e.g., dual-fuel firing systems

Research cluster Smart grids


l Fig. 5, source: Smart gas grids I – principles for the development of smart gas grids; II – development of design principles for the injection and transport of renewable fuels

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and pre-heating systems) were defined. The selection of suitable smart elements (which will depend on the market role of the operator in each case as well as on technical and economic aspects) is facil-itated by the “Smart Bench” assessment tool also developed during the course of the projects (Fig. 5). The sequence of steps recommended for the transforma-tion of energy systems was outlined and summarized in a road map. The studies identified the construction of pilot plants for energy storage (power-to-gas) and load shifting as one of the major tasks. It will be necessary to verify the contribution of such plants to the integration of renew-able energies at specific locations and to identify appropriate grid levels for the interconnection of energy systems.

Smart interconnection elements could reduce the need for grid expansion

These tasks are being performed within the scope of a further research project which uses specific power and gas grids operated by EWE-Netz GmbH as an exam-ple. The locations were selected to ensure that system sections with high renewable energy injection rates were available and that the results could be transferred to other areas in Germany.

The first interim results of this study show that smart interconnection elements allowing the combination of power and gas infrastructure – especially power-to-gas – significantly relieve the burden on rural power grids and therefore reduce the need for grids expansion (Fig. 6).

In the case of typical rural low-voltage grids with low domestic service densities and

with many connected photovoltaic systems, power-to-gas plants could reduce system expansion costs as much as 60 percent by 2050. This assumes that the smart interconnection elements will be controlled by the smart grid. In other words, the smart grid will set the output range of the power-to-gas plants dynamically as a function of the local injection and load situation. This will also reduce the need for the expansion of higher-level medium-voltage grids. These savings should be considered when as-sessing the costs and benefits of the plant. The operation of power-to-gas plants on the basis of market demand would lead to higher contribution margins, for example via participation in the balancing energy mar-ket. However, this would call for additional grid expansion.

In addition, the high capital expenditure for a power-to-gas plant is currently the main challenge. The specific investment for electrolysis units up to 100 kW will need to fall to € 1,000 per kilowatt. With technological developments, improved production processes and growing sales, the necessary cost reductions could be obtained.

A follow-up research project applied the results of the potential assessment in practice. The analysis of real grids provid-ed valuable information on the selection of suitable interconnection points between power and gas grids and for the determi-nation of the marginal cost of interconnec-tion elements.

l Fig. 6 Expansion variations for rural low-voltage grid, source: benefits of smart grid concepts taking into consideration power-to-gas technology for distribution systems

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Integration of biogas potential in gas grid planning

Biogas provides a renewable component for the gas infrastructure. Currently, most of the biogas produced is used directly for power generation. With the intent of ensuring the improved use of biogas for injection into gas grids, a research project determined the quantities of biogas which could be generated, taking sustainability aspects into consideration, and a model for the combination of this potential with the gas infrastructure.

The potential for biogas production in Germany was determined in a further study including specialists and institutions from the fields of agriculture, the biogas industry

and the energy and water industries. This interdisciplinary study indicated the extent to which political expansion targets can be met, taking into consideration soil and water protection as well as efficient gas supplies. In order to make statements concerning the future development of substrate quantities, a substrate-specific projection for 2015, 2020 and 2030 was produced.In addition to the possible developments in substrate availability, additional factors such as demographic change and the probable development of farm animal numbers were considered. The production potential from the various substrates was investigated in a staged framework ranging from theoretical potential to feasible and sustainable potential to economically viable potential. This production potential was then

compared with the injection possibilities of the gas grid available at different locations throughout the year.

To summarize, it can be stated that the quantity of biomethane which could be produced and injected into the German gas grid, taking into account sustainability aspects including soil and water protection as well as energy efficiency, would be 8.6 billion cubic metres in 2020 and 10.3 billion cubic metres in 2030. Thus, it would therefore be possible to meet the targets set by politicians (Fig. 7). However, in order to meet these targets, it will be necessary to convert most of the existing biogas plants into gas injection plants.

l Fig. 7: Biomethane production potential taking sustainability aspects into consideration, source: potential study for the sustainable production and injection of gaseous fuels from renewable sources in Germany (biogas atlas)


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Research clusterPower-to-gas


“Power-to-gas” is generally used to refer to the conversion of growing quantities of surplus electric power into hydrogen by electrolysis or synthetic methane. This conversion allows the indirect storage of large quantities of electric power and therefore stabilizes the power system.

The cluster started work by compiling the data of power-to-gas pilot plants currently under construction or already in operation and presenting the specific features of these plants. The large number of projects at this early stage of this new energy conversion technology and the wide range of specific site concepts shows that power-to-gas is a multi-faceted technology. It is far more than a way of ensuring large-scale power storage. The plants currently being planned for demonstration purposes throughout Germany are still highly complex and will need to be standardized for eco-nomical operation; their energy efficiency will also need to be improved. In particular, the cost situation with respect to the key technical component of these plants, the electrolysis unit, still needs to be optimized.

The power-to-gas research cluster investigated in detail the technical and gas industry conditions and improvement potentials required for the efficient use of this storage technology. It was also found that power-to-gas offers a wide variety of other options; for example, relieving the load on power grids by shifting energy flows to the gas grid. However, green power, as a gas generation resource,

can also be used for the production of an alternative fuel for the mobility sector or for increasing the production rates of biomethane plants.

Apart from the technical and economic requirements to be met by a power-to-gas plant, the cluster worked on the problem of injecting new gases into the public grid – either in the form of hydrogen/natural gas mixtures or in the form of synthetic natural gas. The effects of injection on gross calo-rific value were investigated and methods

and measurement procedures recognized by the authorities for all custody transfer processes were identified. Further inves-tigations will be necessary to determine which gas applications and infrastructure components represent limiting factors for the mixture of hydrogen with natural gas (Fig. 8+ Fig. 9). The applicable codes and standards currently allow hydrogen to be mixed with natural gas in the single-digit percentage range, but also call for the in-dividual assessment of downstream supply structures.

l Fig. 8, source: hydrogen tolerance of natural gas infrastructure including associated facilities

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Power-to-gas: a high-potential storage solution

The DVGW studies have shown that power-to-gas will become increasingly relevant as the share of renewable energy sources in power generation increases. Large storage capacities will be essential if renewables constitute a significant share in power generation. By including existing infrastructure such as natural gas pipelines and underground storage facilities, gas offers considerably greater storage potential than established storage technologies such as pumped storage power stations. Throughout the course of the year, the existing underground storage facilities available in Germany can store about 230

terawatt-hours of natural gas. The hydrogen produced by power-to -gas technology or methane synthesized from this hydrogen is available both to the space heating market and to the mobility sector.

Methanation as an option

In some proposed schemes, the carbon dioxide required for methanation comes from industrial production facilities; in other schemes, renewable energy sources such as biogas are used (Fig. 10). The advantage of methanation is that there are practically no limits for mixing with natural gas if synthetic natural gas is produced. Apart from catalytic methanation, the innovative process of biological methan-

ation is currently being developed. There are two fundamentally different competing processes: firstly, in situ methanation within the biogas plant or digester and secondly processes with special pure cultures in a separate reactor.One of the objectives of the DVGW studies in this research cluster was to assess the optimization potential for catalytic methan-ation combined with electrolysis at a biogas plant and to produce an assessment of the potential of biological methanation. The studies carried out within this cluster aimed to make power-to-gas technology more independent from its function as a conver-sion technology for the chemical storage of electric power. They describe the system benefits of power-to-gas as an interface between a volatile, renewable power system and a flexible gas system with storage capacity. This means that power from re-newable sources can be made available for a variety of applications via gas: in heating and power generation as well is in mobility or as a chemical feedstock.

Effects of the addition of hydrogen

The effects of the addition of hydrogen on gas metering and invoicing were compre-hensively investigated. Among other topics, the state of the art of pure hydrogen me-tering and the hydrogen compatibility of a variety of metering systems used in the gas industry were investigated and methods for cost-effective gross calorific value tracking in distribution systems were considered. This is essential in order to ensure that each customer receives invoices based on the energy content of the gas delivered and to make costly natural gas conditioning unnecessary. Through additional data flows and information processing, as in the case

l Fig. 9, source: hydrogen tolerance of natural gas infrastructure including associated facilities

25

of gross calorific value tracking, the natural gas distribution system becomes a smart grid.

In a technical and economic study on power-to-gas, the design data of the first power-to-gas plants were taken as the basis for defining minimum requirements. In addition, the experience gained during approval planning for gas grid connection was collected and assessed. An overall investigation of the power-to-gas option with methanation was to be made on the basis of the following key questions: what sites are predestined for plants of this type based on carbon dioxide availability? What is the carbon footprint of the various synthesis gases? The objective was to carry out an energy and economic assessment of

process engineering designs and to derive an optimized design for a 10 MW methana-tion pilot plant.

Economic assessment of power-to-gas options

Various power-to-gas approaches were compared with each other in techno-eco-nomic studies. Firstly, these studies consid-ered the question of how the contribution to the stabilization of the power grid is to be valued if no other power storage capacities are available and how a price is to be set for control energy. Another aspect was the contribution to the decarbonization of mobility, i.e. the provision of an almost zero-emissions fuel. Finally, the contribu-tion of power-to-gas to the reduction of CO

2

emissions was valued in financial terms.All in all, all the approaches studied are not economically viable under the present regulatory conditions, if they are considered separately. The challenge will be to allow the market entry of power-to-gas through an effective combination of different ap-proaches. There are some highly promising concepts that are currently being pursued by DVGW.

l Fig. 10, source: techno-economical study of power-to-gas concepts, project segment methanation – an alternative to direct hydrogen injection

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Research clusterGas production and upgrading

Research clusterGas production and upgrading

The gas production and upgrading research cluster investigates process engineering questions connected with the production of gaseous fuels from renewable sources. The objective is to expand the raw material spectrum, especially towards biogenic waste. In addition, this research cluster focus-es on the optimization of the process chain for gas production, upgrading and injection with respect to environmental, economic and energy efficiency factors.

The production and injection of methane produced from biomass offer possibilities of making gas supplies more climate-compati-ble. In addition, the technical potential avail-able could be used to compensate for the decline in German natural gas production. The results of this research cluster were used directly for systems analysis and in grid management projects. Issues relevant to the water industry were considered in cooperation with the responsible DVGW technical committees and the experts of the DVGW Water Technology Centre.

This research cluster focused on the following key questions:

l How can the overall energy efficien-cy of the biomethane process chain be improved while simultaneously reducing production costs?

l How can the methane emissions as-sociated with production and injection be measured most effectively?

l Is it possible to identify and carry out a systems analysis of various connec-tion possibilities between the individual process stages in studies of innovative conversion and upgrading processes?

l What are the possibilities for using industrial and household waste as sub-strates for biogas production, and for the utilization of digester residues as fertiliz-ers? What are the special requirements for the upgrading of biogas produced from the various types of waste with the intent of developing a natural gas substitute and how can these possibilities be assessed?

The objective of these research projects was to analyse the process chain from bi-ogas production up to injection and to con-sider the environmental aspects of biogas injection and digester residue upgrading and utilization. The assessment of overall energy efficiency compared the entire process chain of central power generation at large power plants with the decentralized use of gaseous fuels combined with cogen-eration. In addition to fundamental scientific

and technical research on the thermo-chemical production of synthetic natural gas (SNG) from biomass, another key area of research was the monitoring of various biomethane plants, with the main focus on biogenic waste as a substrate and innova-tive gas upgrading processes. The cluster also included the assessment of emissions along the biomethane process chain. For this purpose, emission measurements were carried out on post-upgrading systems for the elimination of methane emissions in the lean gas and a helicopter-based process for quantitative remote methane detection was tested.

Process engineering innovations

In the associated project of BMBF (the German Federal Ministry of Education and Research) – “Innovative production of gaseous fuels from biomass” – an innovative digestion process, optimized for the upgrading of biogas and injection into the natural gas grid, was developed. This process already produces a gas with considerably higher methane content than with conventional processes directly in the digestion stage. In addition, the gas is made available at a higher pressure.

Due to the advantages of this process, the cost of gas upgrading and injection can be significantly reduced as the need for energy-intensive compression of the biogas can be reduced or even eliminated. Another process engineering innovation that was developed is a scrubbing process based on ionic fluids. In comparison to

27

conventional processes, this new approach offers considerable benefits in terms of lower energy consumption and higher process intensity.

Monitoring of biogas injection II

Measurements at plants using the newly tested gas upgrading processes within the project “Monitoring Biogas II” showed comparable results with other upgrad-ing processes. The gas composition requirements stated in the applicable

DVGW standards were always met. The investigations concerning sampling and analysis of organic silicon compounds showed considerable differences under actual conditions, especially in regards to detection limits, measurement accura-cies and applicability, while comparable results were achieved under laboratory conditions. The processes investigated are generally well-suited for sampling at biogas plants, but will need to be adapted to local conditions before they can be used on site. The field tests using the CHARM(r)

remote detection system at a biomethane plant were also successful. It was possible to show that methane emissions could be measured with sufficient accuracy and that a modern biogas plant designed for gas injection with a gas-tight digester res-idue storage area causes diffuse methane losses of about 0.3 percent of the quantity injected. The project also showed that the methane slip via the lean gas could be reliably reduced below the limit of 0.2 per-cent set by the Gas Grid Access Ordinance by using post-upgrading systems.

Energy and cost savings in biogas upgrading

Another key result is that the newly developed processes of high-pressure fermentation and biogas upgrading with ionic fluids will probably allow primary energy savings of 20 to 25 percent with cost savings in excess of 20 percent (Fig. 12). In addition, it was possible to make a detailed evaluation of gaseous emissions along the biomethane process chain and the potential hazards associated with the spreading of digester residue on fields. While gaseous emissions do not represent a problem in the case of plants designed in accordance with the state of the art, digester residues may contain organic pollutants, medicinal materials or heavy metals, as well as problematical microor-ganisms, depending on the source of the materials used.

l Fig. 11, source: DWGW energie | wasser – praxis, z/8 2013, pp. 40 ff.

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Results with high practical relevance

The results of the studies are highly relevant, both with respect to biomethane technology currently available and with respect to biogas injection plants already installed in Germany. In particular, the new process engineering developments indicate considerable potential for the improvement of energy and cost efficien-cy and could therefore have a positive effect on public and political discussions concerning the future use of bio-energy in Germany. Furthermore, the results for the coupling of biogenic processes with

power-to-gas concepts could be beneficial. The results should be especially useful for the design of pilot and demonstration plants in order to ensure that these inno-vative concepts can be put into practice in the near future.

In addition, coupling with power-to-gas systems (e.g. biological methanation) should be investigated in greater detail.

By integrating with publicly subsidized research projects in the field of renewa-ble energies, it was possible to acquire additional project funding in the amount

of about € 5 million for the topics of this cluster and the power-to-gas cluster.

Forschungscluster Gaserzeugung und -aufbereitung

l Fig. 12, source: BMBF project “B2G – innovative production of gaseous fuels from biomass” (www.b-2-g.de)

29

l Fig. 13, source: BMBF project “B2G – innovative production of gaseous fuels from biomass” (www.b-2-g.de)

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Research cluster Cogeneration and utilization technologies


The cogeneration and utilization technologies research cluster is concerned with questions related to innovative gas-plus technologies, ranging from individual processes to comprehensive overall system anal-yses. The cluster aims to investigate utilization concepts and efficient stor-age technologies as well as the role of cogeneration in decentralized supply structures. The objective is to ensure highly efficient system operation by taking a total systems approach.

The results of the DVGW innovation cam-paign on cogeneration technologies raised questions concerning utilization concepts and optimization for buildings. A distinction was drawn between different types of projects: non-residential and residential buildings, divided into single family homes and apartment houses.

This research cluster focused on the following key aspects:

l Energetic and exergetic optimization of operation; optimization of the overall “building” system taking into considera-tion the entire energy supply structure for power, gas and heat

l Analyses concerning the integration of renewable energy sources

l Analyses of the potential for energy storage; utilization concepts considering new storage technologies (decoupling of the cogeneration system from the building as a necessary step towards power-prior-ity operation; smart home, virtual power station)

l Cooling/air conditioning as a meaning-ful addition to decentralized waste heat utilization

l Analyses of impacts and influences on operational behaviour and efficiency

The basic approach included analyses of load curves and user profiles, the further development of skills for the simulation using the Modelica simulation tool and the initiation and support of demonstration projects, especially in relation to smart homes/smart grids, as well as the demon-stration of sustained CO

2 reduction.

In regards to gas-plus technologies (gas condensing boiler plus solar heating, gas-fuelled heat pump plus cogeneration), this cluster covered the following aspects:

l Development and validation of oper-ation strategies (heating and air condi-tioning) with optimized energy storage in residential and non-residential buildings

l Consideration of the different reno-vation statuses of buildings with respect to conversion to an efficient a mode of operation as possible

l Effects of gas composition chang-es, especially the effect of hydrogen on operational behaviour and the efficiency of gas-plus technologies and the effect of methane number changes on cogeneration plants using four-stroke internal combus-tion engines

Solar heating, heat pumps, micro- cogeneration plants

Solar heating is especially well suited for meeting statutory requirements for the use of renewable energy sources in new buildings. Condensing boiler technology, l Table 1, source: Cogeneration in the context of the overall system of building and energy equipment

31

an established standard technology, offers potential for optimization in combination with solar heating, both with respect to the integration of solar hot water preparation and especially with respect to support for solar heating.

Gas-fuelled heat pumps are a high-ef-ficiency alternative to the heating of buildings. The use of solar collectors as an ambient heat source is still relatively new. As temperatures are potentially higher than with other ambient heat sources, higher efficiency is to be expected. Particularly for heat pumps, optimum integration into the overall heating system including ambient heat is especially important for efficient opera-tion. User behaviour must also be taken into consideration. Micro-cogeneration plants for the generation of power and heat are becoming more and more widely available and are seen as a high-efficien-cy alternative to conventional heating sys-tems, especially in residential buildings. Micro-cogeneration systems can help in achieving climate protection objectives and can increase the share of power from cogeneration in total power generation.

Gas-plus technologies put on the test

Modernization models for defined refer-ence projects were developed on the basis of building potential investigations and analyses of buildings and heating systems, taking into account statutory requirements and possible subsidies.

Design calculations for energy system modernization using simplified planning aids prepared by various manufacturers and specialist associations only resulted in balanced environmental and economic results for a limited number of individual cases. This can be explained by the com-plexity of the systems concerned. Following research concerning existing plant designs and design criteria, calculations were therefore made for certain defined exam-ples. Comprehensive analyses of system technology parameters were conducted in order to isolate the factors affecting

efficiency. Simulation models based on the Modelica program for total systems analysis also allowed the modelling of dynamic processes.

The projects investigated both convention-al gas condensing boilers and gas-plus technologies (gas-fuelled heat pumps and micro-cogeneration plants). The integration of ambient heat, especially through solar heating and through geothermal probes and surface collectors, was also covered. Apart from market overviews concern-ing the various gas-plus technologies,

l Fig. 14, source: Modernization approaches for apartment buildings

32

suitability comparisons were made on the basis of theoretical and experimental studies. For this purpose, advanced test methods allowing a dynamic mode of operation with a reproducible user profile were applied and verified. On this basis, it was possible to establish more practically relevant tests for overall systems (Table 1).

Other points which were considered included waste heat utilization potential, possible combinations of plants and synergies in combination with insulation. Field test data from the individual plants were also evaluated in order to allow for a comparison between laboratory and practical application data and to study the effects of user behaviour and building-spe-cific parameters. Basic user behaviour in connection with primary energy and energy efficiency was assessed by an online survey with 1,000 participants. The results were taken into account in the evaluation which considers renovation alternatives on the basis of the criteria of primary and final energy demand, emissions and economic aspects (Fig. 14).

Results and recommendations for new and existing systems

Sensitivity analyses of the main siz-ing criteria can be used for developing recommendations for appropriate systems to be used in new and existing buildings. Combined condensing boiler/solar heating systems are especially well-suited for meeting statutory requirements for the use of renewable energy sources in new buildings.

However, the potential of these systems can only be exploited in full if the use of

solar heating systems is already taken into account at an early stage in the planning process for the building. It is difficult to state general recommendations for existing buildings as the main parameters are already defined here. For the efficient operation of the solar heating system, an adequate control system is especially important.

The selection of a suitable source of am-bient heat generally depends on the local conditions of the building. Groundwater as a heat source can ensure the highest possible efficiency over the entire year. However, realization is cost-intensive and

the approvals procedure is complex. For a gas-fuelled heat pump, less ambient heat is needed than with a comparable electric heat pump. In the case of the gas-fuelled heat pump, it has been found that the re-quirements of the Renewable Heat Energy Act (EEWärmeG) can be met provided that the system is well designed with respect to the general conditions of the building.

It can also be shown that all the cogen-eration systems available on the market can be operated at high levels of energy efficiency provided that they are suitably sized for the building concerned. A more detailed comparison of micro-cogeneration

l Fig. 15, source: Opportunities for cogeneration in residential buildings, RWTH University Aachen, EONERC EBC


33

systems with a condensing boiler system and electric or gas-fuelled heat pump as an additional heating unit indicates that a combination of high-efficiency technol-ogies may be beneficial with respect to environmental aspects. Investigations of the replacement of electric warm water heating in washing machines and dish-washers identified a further improvement in the operating time of the cogeneration plant which can be used for smoothing load peaks.

Combination of insulation and cogeneration systems

Another study is concerned with syner-gies from the combination of insulation with cogeneration systems. Combined implementation leads to optimum results in terms of primary energy efficiency and environmental considerations.

In regards to the use of micro-cogenera-tion systems, it can be shown that high power to heat ratio is directly connected with comparatively high efficiency and long running time. The analysis also indicates that the economics of the system improve if the utilization of electric power is maxi-mized. As a result, the operating hours of the cogeneration plant and the share of electric power utilization are key parame-ters for the optimum sizing of cogeneration plants with respect to economic aspects.The results lead to recommendations for the modernization of existing buildings in the short term on the basis of environmen-tal and economic criteria. Information from the refurbishment models is a strategic planning tool for both decision-makers in the field of housing policies and for investors. Decentralized supply structures

should be retained especially in apartment buildings. One of the key results is that the potential of gas-plus technologies within the context of the energy transition is con-siderable as significant added value can be achieved inform the modernization of energy systems for buildings. This means that comprehensive insulation work can be reduced to the minimum which is required with respect to energy considerations, with the same CO

2 reduction potential.

Public relations work has been boosted by the project-related establishment of demonstration centres at the institutes involved in the studies. Users, plant operators and installation contractors are familiarized with the complex technology through practical hands-on training and further education courses (Fig. 16).

l Figure. 16, source: DVGW

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l Cluster | Gas in an integrated energy system

l Cluster | Smart grids

Project overview ofDVGW gas innovation campaign

First

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First

half

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Project title Participants

Assessment of energy supplies with gaseous fuels supplied by pipeline compared with other energy sources, Part I Systems analysis, Part I

DBI · DVGW-EBI · GWI

Assessment of energy supplies with gaseous fuels supplied by pipeline compared with other energy sources, Part II – Effects of modern gas technologies in domestic energy supplies on efficiency and the environment Systems analysis, Part II

DBI · DVGW-EBI · GWI · Jülich Research Centre IEK-STE

Development of modular approaches for methane and hydrogen production, storage and injection into the natural gas grid

DBI · DVGW-EBI · E.ON ·Fraunhofer IWES · OGE ·VNG Gasspeicher

Modelica simulation of the overall system of user/buildings/energy systems GWI · RWTH Aachen EONERC EBC · XRG

Synergy effects between gas and power grids – utilization of gas grids and storage facilities for the integration of power from renewable sources and to relieve the load on power grids

DBI · Wuppertal Institute

Analysis of the climate protection potential of the utilization of renewable hydrogen and methane

PIK

Investigation of the contribution of decentralized cogeneration to covering the residual load with reference to renewable power generation and power consumption

DBI · DVGW-EBI ·Jülich Research CentreIEK-STE · Fraunhofer IWES ·GWI · RWTH Aachen EONERCEBC

Integration of fluctuating renewable energies through the convergent use of power and gas grids KonStGas (with BMU support)

DBI · DVGW-EBI · Jülich research Centre IEK-STE · Fraunhofer IWES · GWI · KIT-IIP · RWTH Aachen IAEW · TU Clausthal ITE · TU Dresden


Smart gas grids I – Principles for the development of smart gas grids DBI · DVGW-EBI

Smart grids II – Development of design principles for the injection and transport of renewable fuels

DBI · DVGW-EBI

Potential study on the sustainable production and injection of gaseous renewable fuels in Germany (biogas atlas)

DBI · DVGW-EBI · DVGW-TZW · Fraunhofer UMSICHT

Use of smart grid approaches considering power-to-gas technologies in distribution grids

DBI · DVGW-EBI · EWE · RWTH Aachen IAEW · Uni Wuppertal EVT

Study concerning the use of power-to-gas technology for relieving the load on 110 kV power distribution grids

DBI · DVGW-EBI · E.ON Avacon · EWE · RWTH AachenIAEW · Uni Wuppertal EVT

2010 2011 2012 2013 2014 2015

2010 2011 2012 2013 2014 2015

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l Cluster | Gas production and upgradingFir

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Energy analysis of thermochemical production of gaseous fuels followed by decentralized use with innovative utilization technologies

DVGW-EBI

Monitoring of biogas injection II DBI · DVGW-EBI

Use of industrial and domestic waste for biogas injection DBI · DVGW-EBI ·DVGW-TZW · GWI

B2G (biomass to gas) – gaseous fuels from biomass (with BMBF support) DVGW-EBI · EnBW · KIT-IIP · MiRO · TBM · Uni Hohenheim LAB · Uni Stuttgart IFK · ZSW

Storage of electric power from renewable sources in the natural gas grid – water electrolysis and synthesis of gas components (with BMBF support)

DVGW-EBI · EnBW · Fraun-hofer ISE · h-tec · IOLITEC · Outotec

2010 2011 2012 2013 2014 2015

l Cluster | Power-to-gasFir

st ha

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Techno-economic study of power-to-gas concepts a Plant designs and optimization of operation a Methanation – an alternative to direct hydrogen injection a Economics and systems analysis of power-to-gas approachesGas-Konzepten

DBI · DVGW-EBI · Outotec · Uni Linz

Techno-economic study of biological methanation for power-to-gas concepts DVGW-EBI · Krajete · MicrobEnergy

Hydrogen tolerance of natural gas infrastructure including associated plants DBI

Effects of hydrogen on energy metering and invoicing DBI · E.ON · Uni Bochum

Extended investigation and structuring of hydrogen tolerance of natural gas infra-structure

DBI

Investigations concerning an increase in the maximum hydrogen limit (2 % by volume) for the CNG tanks of new natural gas vehicles

DBI

Chemical storage of renewable energy through hydrogen addition to porous rock storage facilities – basic principles and in situ field test

RAG

2010 2011 2012 2013 2014 2015

36

Project overview ofDVGW gas innovation campaign

l Cluster | Cogeneration and utilization technologies Fir

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“Smart heating”; condensing boiler plus solar heating in the building/heating equip-ment system

GWI

Modernization approaches for apartment houses GWI

Continuous exhaust gas discharge from gas-fired heat pumps with condensing oilers GWI

Utilization potentials of gas-fuelled heat pumps – gas-fuelled heat pumps with solar heating systems in the system of building/heating equipment/user

GWI

Utilization potentials of gas-fuelled heat pumps – optimization of ambient heat integration via geothermal probe/soil collectors/ambient air

DBI · DVGW-EBI · GWI · IGWP

Cogeneration in the building/heating equipment system GWI

Utilization potentials of innovative gas utilization technologies – fuel cells in the building/heating equipment system

GWI

Investigation of the effects of gas composition changes on industrial applications DBI · DVGW-EBI · GWI

Investigations on the injection of hydrogen into a natural gas distribution grid – effects on the operation of existing gas equipment, gas-plus technologies and combustion control strategies

DVGW-EBI · E.ON-Hanse · E.ON-Technologies · GWI · sh-netz

Innovation City – from laboratory to demonstration: model cogeneration test for CO2

reduction in the Innovation City

GWI

2010 2011 2012 2013 2014 2015

DBI-Gruppe

DVGW-EBI

DVGW-TZW

E.ON

E.ON Avacon

E.ON Hanse

E.ON Technologies

EnBW

EWE

Forschungszentrum Jülich IEK-STE

Fraunhofer ISE

Fraunhofer IWES

Fraunhofer UMSICHT

GWI

h-tec

IGWP

IOLITEC

KIT-IIP

DBI Gas- und Umwelttechnik GmbH, Leipzig, und DBI-Gastechnologisches Institut gGmbH, Freiberg

DVGW Research Centre at the Engler-Bunte Institut of Karlsruhe Institute of Technology (KIT), Karlsruhe

DVGW Water Technology Centre, Karlsruhe

E.ON Energie Deutschland GmbH, Munich

E.ON Avacon AG,Helmstedt

E.ON-Hanse AG, Quickborn

E.ON Technologies GmbH, Essen

EnBW Energie Baden-Würtemberg AG, Karlsruhe

EWE Aktiengesellschaft, Oldenburg

Jülich Research Centre, Institute for Systems Analysis and Technology Evaluation (IEK-STE)

Fraunhofer Institute for Solar Energy Systems (ISE), Freiburg

Fraunhofer Institute for Wind Energy and Energy System Technology (IWES), Kassel

Fraunhofer Institute for Environmental, Safety, and Energy Technology UMSICHT, Oberhausen

Gas- und Wärme-Institut Essen e.V., Essen

h-tec Wasserstoff-Energie-Systeme GmbH, Lübeck

Initiative Gaswärmepumpe (bis 2012, jetzt Zukunft ERDGAS e.V., Berlin)

IOLITEC Ionic Liquids Technologies GmbH, Heilbronn

Karlsruhe Institute of Technology, Institute for Industrial Production, Karlsruhe

Krajete

MicrobEnergy

MiRO

OGE

Outotec

PIK

RAG

RWTH Aachen IAEW

RWTH Aachen EONERC EBC

sh-netz

TBM

TU Clausthal ITE

TU Dresden

Uni Bochum

Uni Hohenheim LAB

Uni Stuttgart IFK

Uni Wuppertal EVT

VNG Gasspeicher

Wuppertal Institut

XRG

ZSW

Krajete GmbH, Linz, Austria

MicrobEnergy GmbH, Schwandorf

MiRO Mineraloelraffinerie Oberrhein GmbH & Co. KG. Karlsruhe

Open Grid Europe GmbH, Essen

Outotec GmbH, Frankfurt

PIK Potsdam Institute for Climate Impact Research, Potsdam

RAG Rohöl-Aufsuchungs Aktiengesellschaft, Vienna, Austria

RWTH Aachen, Institute of Power Systems and Power Economics (IAEW), Aachen

RWTH Aachen E.On Energy Research Center, Institute for Energy Efficient Buildings and Indoor Climate, Aachen

Schleswig-Holstein Netz AG, Quickborn

TBM Technologieplattform Bioenergie und Methan GmbH & Co. KG, Geislingen

Technical University of Clausthal, Institute of Petroleum Engineering

Technical University of Dresden

University of Bochum (RUB), Department of Thermodynamics

University of Hohenheim, State Institute of Agricultural Engineering and Bioenergy (LAB)

University of Stuttgart, Institute of Combustion and Power Plant Technology, Stuttgart

University of Wuppertal, Department of Electric Power Supply Engineering

VNG Gasspeicher GmbH, Leipzig

Wuppertal Institute for Climate, Environment, Energy, Wuppertal

XRG Simulation GmbH, Hamburg

Zentrum für Sonnenenergie- und Wasserstoff-Forschung Baden-Württemberg (ZSW), Stuttgart

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Publication details

Published byDVGW Deutscher Verein desGas- und Wasserfaches e. V.Technisch-wissenschaftlicher VereinJosef-Wirmer-Straße 1-353123 Bonn

Phone: +49 228 9188-5Fax: +49 228 9188-990Email: [email protected]: www.dvgw.de

ContactFrank GröschlPhone: +49 228 9188-819Fax: +49 228 9188-945Email: [email protected]

Photo acknowledgementsTitle photos: DVGW (Roland Horn, Berlin)Fotolia.com (Simon Kraus)Fotolia.com (artjazz)shutterstock.com (Nadezhda Shoshina)shutterstock.com (Juergen Faelchle)shutterstock.com (PeJo)

First edition, 2014

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