Geothermal Energy, an option for hydrogen production?
Presentation given by
Ólafur G. FlóvenzGeneral director of Iceland GeoSurvey
and Secretary of the International Geothermal Association
at International seminar on the Hydrogen Economy for Sustainable Development, Reykjavík 28.-29. September 2006
Content
• The geothermal resources in the world• Basic geothermal concepts• The Icelandic road to renewable energy
society• Concluding remarks
The heat of the Earth
> 5000 °C
> 3000 °C
> 1000 °C
~ 30 °C/km
Heat is constanly
produced within the
Earth from decay of
radioactive material.
The heat is moved to
the surface by heat
conduction,
convection or
advection.
The heat stored in the Earth´s crust
• The total amount of heat stored in the crust is of the order of 5.4 billion EJ (5.4* 109 EJ).
• If we could use 0.1% of this it would satisfy the world energy consumption for 13.500 years.
• The geothermal energy resource is huge but we have technical problems to harness it.
World Energy Assessment 2000
Hydro-power
Biomass Solarenergy
Windenergy
Geothermalenergy
EJ per year
50276
1575
640
5000
0
1000
2000
3000
4000
5000
6000
Worldwide technical potential of renewable energy sources (EJ per year)
Key question
• How can we extract and utilize the geothermal heat for sustainable energy production with low environmental impact?
Geothermal electricity Installed capacity MWe 2004
Kenya 127
Mexico 953Guatemala 33El Salvador 161Nicaragua 77Costa Rica 163
China 29
Russia 79
Philippines1931
Indonesia 797
Turkey 20
New Zealand 437
Thailand 0.3
USA 2544
Ethiopia (7)
Italy 790
Iceland 202
Azores 16Japan 535
Australia 0.2
Guadeloupe 15
Austria 1Germany 0.2
Papua N Guinea 6
Slide from Ingvar Birgir Friðleifsson
Basic geothermal concepts
Three main types of geothermal fields for electricity production:
• High temperature fields• Medium temperature fields• Low temperature fields
We distinguish between:
Conventional geothermal systemsEnhanced geothermal systems
High temperature fields
• 200 – 350°C• Depth: 1 – 3 km• Related to volcanism and
plate boundaries• Suitible for electricity
production with conventional turbines
• Small content of hydrogen and hydrogen sulfide in the emission Nesjavellir, Iceland. 300°C fluid
used to produce electricity
Medium temperature fields
• 120-200°C• 1 – 5 km• Mostly found in deep
sedimentary basins around the world as well as in volcanic areas
• High flowrates necessary for electricity
• Binary systems needed for electricity production
Húsavík, Iceland. 124°C water
used to produce electricity
Low temperature fields
• Below 100 °C
• At 1 – 3 km depth
• Mostly found in sedimentary basins and fracture zones around the world
• Suitible for space heating, balneology, fish farming etc.
• Not for suitible for electricity nor hydrogen production
HOT ROCK
COLD ROCK
Power PlantMarket
Borhole
Fluid recharge
Permeable fractures
Conventional geothermal system
Artificially enhanced permeability
HOT ROCK
COLD ROCK
Production well
Power PlantMarket
Enhanced geothermal system (EGS)
Injection well
Developing techniques for EGS
• Experiments ongoing at several places, mainly in central Europe and Australia
• If the outcome will be positive there is huge potential for distributed small scale electricity production from medium temperature fields in many countries that could be used for hydrogen production
Near Berlin in Germany
The geothermal progress in Iceland:
The Icelandic road to the renewable energy society
Source: Árni Ragnarsson, Orkustofnun
Primary energy consumption in Iceland 1940-2005
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005
PJ
Hlutfallsleg notkun
0%
20%
40%
60%
80%
100%
1940 1950 1960 1970 1980 1990 2000
Vatnsorka
Jarðhiti
Olía
Kol
Mór
Vatnsorka
Jarðhiti
Olía
Kol
Geothermal
Hydro
Oil
Coal
Coal
Oil
Geothermal
Hydro
90 MW
100 MW
120 MW
46 MW
60 MW
3 MW
2 MW
Source Árni Ragnarsson, Orkustofnun
Space heating in Iceland by sources 1970-2002
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
1970 1975 1980 1985 1990 1995 2000
Fossil fuelsElectricity
Geothermal88%
11%
1%
Source Orkustofnun
Air pollution from space heating Air pollution from space heating
disappeared in Reykjavikdisappeared in Reykjavik
Reykjavik in 1933 at the beginning of geothermal space
heating, still covered with smoke from coal heatings,
Reykjavik 2000: All houses geothermallyheated
Reykjavik 2000: All houses geothermallyheated
The reason for the good result in Iceland
Governmental support actions: – Intensive support to geothermal
research
– Risk loans
– Favourable legal and regulatory environment
How can we use geothermal energy in Iceland for hydrogen production?
• Produce electricity from geothermal and then hydrogen by electrolysis.
• Extract hydrogen directly from geothermal gas or through chemical processes.
Hydrogen by electrolysis in Iceland
• Electricity from geothermal energy is now produced in Iceland at competititve prices
• The geothermal resources of Iceland are large enough to provide enough electricity to produce hydrogen for the local transport sector
• The cost of large scale hydrogen production from electrolysis could be similar to the price of petrol today.
Hydrogen from geothermal gas
• Geothermal gas emission from power plants contain pure hydrogen and hydrogen sulfide.
• Different concentration from site to site
• Not a major soure for hydrogen in Iceland but might contribute to hydrogen driven transport fleet.
• Technically possible – question of cost• Desirable to remove H2S from the emission
Concluding remarks I
• The Icelandic experience shows that geothermal energy can contribute considerably to renewable energy production world-wide.
• There are large conventional geothermal resources available worldwide.
Power plant in Turkey
Concluding remarks II
• New technologies based on the concepts of Enhanced Geothermal Systems could multiply the possibilities of geothermal energy production.
• The possibility of worldwide small scale production of electricity from geothermal systems might in the furture be an option for distributed hydrogen production in many countries.
• The relative cost of hydrogen production is a key issue for the future development.
Concluding remarks III
• Th energy that can be produced from geothermal in Iceland at competitive prices is much more than would be needed to produce hydrogen for the transport sector in the country.
• Iceland could in near future become a totally renewable energy society based on geothemal, hydropower and hydrogen, if hydrogen can be produced at competitive prices.
Thank you for your attention