Post on 11-Jan-2016
transcript
ICELAND GEOSURVEY
Geothermal projects in IcelandGeothermal projects in Iceland
Ólafur G. FlóvenzGeneral director of ISOR
Presentation at “Geothermal Energy - Benefits and Potential”
an event in Brussels on February 1st 2008 during
European Union Sustainable Energy Week
www.isor.is
The internal heat of the Earth
The heat comes from from decay of radioactive material.
0.1% of the energy that is stored in Earth’s crust could satisfy the world energy consumption for 10.000 years.
> 5000 °C
> 3000 °C
> 1000 °C
~ 30 °C/km
ICELAND GEOSURVEY
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EJ per year
50276
1575
640
5000
0
1000
2000
3000
4000
5000
6000
Worldwide technical potential of renewable energy sources (EJ per year)
World Energy Assessment 2000
Hydro-power
Biomass Solarenergy
Windenergy
Geothermalenergy
The heat stored in the Earth´s crust
The geothermal energy resource is huge
but we have technical problems to harness it.
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Renewable energy – Electricity 2005
Production TWh %
Hydro 2837 89.0
Biomass 183 5.7
Wind 106 3.3
Geothermal 57 1.8
Solar 5 0.2
Tidal <2 <0.1
Source: WEC 2007 Survey of Energy Resources, 427-437. World Energy Council 2007 (www.worldenergy.org)
Key question
How can we extract and utilize the geothermal heat for sustainable energy production with low environmental impact?
ICELAND GEOSURVEYwww.isor.isPhoto: Anette K. Mortensen
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Some concepts of geothermal energy
Three main types of geothermal fields for electricity production:
– High temperature fields
– Medium temperature fields
– Low temperature fields
We distinguish between:
– Conventional geothermal systems
– Unconventional geothermal systems
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High temperature fields
– 200 – 350°C
– Depth: 1 – 3 km
– Related to volcanism and plate boundaries
– Suitible for electricity production with conventional turbines
Nesjavellir, Iceland. 300°C fluid used to produce electricity
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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
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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.
Photo: Sigurdur Sveinn Jónsson
www.isor.isHOT ROCK
COLD ROCK
Power PlantMarket
Borhole
Fluid recharge
Permeable fractures
Conventional geothermal system
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Almost all geothermal power plants in the world today are conventional
Photo: Ingavar Birgir Friðleifsson
Olkaria, Kenya
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Unconventional geothermal fields are of two main types:
Enhanced Geothermal Systems (EGS)
Supercritical Geothermal Systems (SGS)
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Artificially enhanced permeability
HOT ROCK
COLD ROCK
Production well
Power PlantMarket
Enhanced geothermal system (EGS)
Injection well
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Primary energy consumption in Iceland 1940-2006
ICELAND GEOSURVEYSource: Orkustofnun
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Energy sources used for space heating 1970-2005
ICELAND GEOSURVEYSource: Orkustofnun
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Icel
and
Fin
lan
d
No
rway
Sw
eden
Den
mar
k
Source: Samorka, Iceland
Cost of house heating in the Nordic countries
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From fossil fuel to geothermal:The environmental benefit
Before geothermal space heating: Reykjavik in 1933 covered with smoke from coal heatings,
With geothermal space heating: Reykjavik in 2008, almost same view but without visible air pollution
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Geothermal fields and installed power in geothermal plants
120 MW120 MW
76 MW
60 MW
3 MW
2 MW+ 400 MW 2015
+ 200 MW before 2015 ?
+ 400 MW before 2015
100 MW
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The magic Icelandic progress
– Favourable, but not unique geological conditions.
– High public acceptance.
– Political willingness:
• Good regulatory and legal framework.• Strong initial governmental support for research,
capacity building and risk sharing funds.
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Favourable geological conditions
• Intersection of a hot spot and a oceanic Ridge.
• Repeated magmatic intrusions keeps the crust warm.
• Seismic activity opens pathways for fluid to extract the heat.
Hot spot
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The geothermal potential in Iceland
– The generating capacity from known high temperatrue fields is of the order of 25 TWh/y assuming heat extraction to 3 km depth.
– In addition there are 1,50x1021 J stored energy above 200°C between 3 and 5 km in the volcanic zone in extensional environment. Converting only 1% of this energy to electricity could yield additional 40 TWh/y for 100 years.
– To-day the generating capacity in Iceland is 480MWe. The total potential is unknown, but might be as a high as 8000 MWe , depending on the technical progress in the near future.
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www.isor.isPhoto:GOF-9. March 2001, 11:35:48
Public acceptance: The Blue Lagoon
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Volcanism and earthquakes are important natural resources!
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Are the mid-oceanic ridges the future energy resource?
– About 600 km of the axis of the Mid-Atlantic Ridge are in Icelandic waters.
– Very high temperatures at shallow depths below the ocean bottom.
– Could we develop methods to produce 30.000 MW of electricity from oceanic ridges in the future?
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The Icelandic geothermal experience shows that
– Geothermal energy can be produced in a sustainable and feasible way with low environmental impact.
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Photo: Emil Thor
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To increase the world wide share of geothermal electricity production we need:
– Strong support for research, especially for unconventional geothermal resources.
– Support action to implement geothermal plants in the developing countries.
– Education and dissemination of geothermal know-how.
– Favourable legal and regulatory framework.
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ICELAND GEOSURVEYwww.isor.isPhoto: Gudmundur Steingrímsson
Thank you for your attention