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