Enhanced geothermal systems
Encyclopedia
Enhanced Geothermal System (EGS) is a new type of geothermal power
technology that does not require natural convective
hydrothermal resources. Until recently, geothermal power systems have exploited only resources where naturally occurring heat, water, and rock permeability
are sufficient to allow energy extraction. However, by far the most geothermal energy within reach of conventional techniques is in dry and impermeable rock. EGS technologies enhance and/or create geothermal resources in this hot dry rock (HDR) through 'hydraulic stimulation'.
When natural cracks and pores do not allow economic flow rates, the permeability
can be enhanced by pumping high-pressure cold water down an injection well
into the rock. The injection increases the fluid pressure in the naturally fractured rock, mobilizing shear events that enhance the system's permeability. This process, termed hydro-shearing,
is substantially different from hydraulic tensile fracturing
used in the oil and gas industries.
Water travels through fractures in the rock, capturing the rock's heat until forced out of a second borehole as very hot water. The water's heat is converted into electricity
using either a steam turbine
or a binary power plant system. All of the water, now cooled, is injected back into the ground to heat up again in a closed loop
.
EGS technologies, like hydrothermal geothermal, can function as baseload resources that produce power 24 hours a day, like a fossil fuel
plant. Unlike hydrothermal, EGS appears to be feasible anywhere in the world, depending on the economic limits of drill depth. Good locations are over deep granite
covered by a 3–5 km (1.9–3.1 ) layer of insulating sediments that slow heat loss. EGS wells are expected to have a useful life of 20 to 30 years before the outflow temperature drops about 10 °C (50 °F) and the well becomes uneconomic. If wells are left for 50 to 300 years the temperature will recover.
EGS systems are currently being developed and tested in France
, Australia
, Japan
, Germany
, the U.S.
and Switzerland
. The largest EGS project in the world is a 25-megawatt demonstration plant currently being developed in Cooper Basin
, Australia. Cooper Basin has the potential to generate 5,000–10,000 MW.
The largest project in the world is being developed in Australia's Cooper Basin by Geodynamics
. The Cooper Basin
project has the potential to develop 5–10 GW. Australia now has 33 firms either exploring for, drilling, or developing EGS projects. Australia's industry has been greatly aided by a national Renewable Portfolio Standard
of 25% renewables by 2025, a vibrant Green Energy Credit market, and supportive collaboration between government, academia, and industry.
Germany's now 25 cent/kWh Feed-In Tariff
(FIT) for geothermal energy has led to a surge in geothermal development, despite Germany's relatively poor geothermal resource. The Landau partial EGS project is profitable today under the FIT. Drawing on the success of the Landau project, EGS Energy are developing sites in the UK. The first of these will be built in collaboration with the Eden Project
.
The AltaRock Energy
effort is a demonstration project being conducted to prove out the company's proprietary technology at the site of an existing geothermal project owned and operated by NCPA
in The Geysers
, and does not include power generation. However, any steam produced by the project will be supplied to NCPA's flash turbines under a long-term contract.
On 30 May 2007, then Australian opposition environmental spokesperson and current Minister for the Environment, Heritage and the Arts
Peter Garrett
announced that if elected at the 2007 Australian Federal Election, the Australian Labor Party
would use taxpayer money to subsidise putting the necessary drilling rigs in place. In an interview, he promised:
, France, has recently connected its 1.5 MW demonstration plant to the grid. The Soultz project has explored the connection of multiple stimulated zones and the performance of triplet well configurations (1 injector/2 producers).
Induced seismicity in Basel
led to the cancellation of the EGS project there.
The Portuguese government awarded, in December 2008, an exclusive license to Geovita Ltd to prospect and explore geothermal energy in one of the best areas in continental Portugal. An area of about 500 square kilometers is being studied by Geovita together with the Earth Sciences department of the University of Coimbra's Science and Technology faculty, and the installation of an Enhanced Geothermal System (EGS) is foreseen.
A commercial-scale project near Redruth is also planned. The plant, which has been granted planning permission, would generate 10 MW of electricity and 55 MW of thermal energy and is scheduled to become operational in 2013–2014.
In fiscal year 2002, this vision translated into completing "preliminary designs for five competitively selected projects employing EGS technology," and the selection of one project for "full-scale development" at the Coso Hot Springs geothermal field at the US Naval Weapons Air Station in China Lake, California, and two additional projects for "preliminary analysis from a new solicitation" at Desert Peak in Nevada and Glass Mountain in California. Funding for this effort totaled $1.5 million.
In fiscal year 2003, $3.5 million was appropriated to launch the Coso project, with the aim of improving the permeability of an existing poorly performing well, and to complete the conceptual design and feasibility studies at the Desert Peak and Glass Mountain sites.
The fiscal year 2004 request for $6 million was to "[s]tep up work on EGS cost-shared projects' at the three sites, to include "drilling and reservoir stimulation experiments" at one and drilling a production well at another.
The US Department of Energy USDOE issued two Funding Opportunity Announcement
s (FOAs) on March 4, 2009 for enhanced geothermal systems (EGS). Together, the two FOAs offer up to $84 million over six years, including $20 million in fiscal year 2009 funding, although future funding is subject to congressional appropriations.
The DOE followed up with another FOA on March 27, 2009, of stimulus funding from the American Reinvestment and Recovery Act for $350 million, including $80 million aimed specifically at EGS proejcts,
The case of induced seismicity in Basel
merits special mention; it led the city (which is a partner) to suspend the project and conduct a seismic hazard evaluation, which resulted in the cancellation of the project in December 2009.
Risks associated with "hydrofracturing induced seismicity are low compared to that of natural earthquakes, and can be reduced by careful management and monitoring" and "should not be regarded as an impediment to further development of the Hot Rock geothermal energy resource".
Research conducted at Los Alamos National Laboratories and Lawrence Berkeley National Laboratories examined the use of supercritical CO2
, instead of water, as the geothermal working fluid, with favorable results. CO2 has numerous advantages for EGS:
A 2006 report by MIT, and funded by the U.S. Department of Energy, conducted the most comprehensive analysis to date on the potential and technical status of EGS. The 18-member panel, chaired by Professor Jefferson Tester of MIT, reached several significant conclusions:
Geothermal power
Geothermal energy is thermal energy generated and stored in the Earth. Thermal energy is the energy that determines the temperature of matter. Earth's geothermal energy originates from the original formation of the planet and from radioactive decay of minerals...
technology that does not require natural convective
Convection
Convection is the movement of molecules within fluids and rheids. It cannot take place in solids, since neither bulk current flows nor significant diffusion can take place in solids....
hydrothermal resources. Until recently, geothermal power systems have exploited only resources where naturally occurring heat, water, and rock permeability
Permeability
Permeability, permeable and semipermeable may refer to:*Permeability , the degree of magnetization of a material in response to a magnetic field...
are sufficient to allow energy extraction. However, by far the most geothermal energy within reach of conventional techniques is in dry and impermeable rock. EGS technologies enhance and/or create geothermal resources in this hot dry rock (HDR) through 'hydraulic stimulation'.
When natural cracks and pores do not allow economic flow rates, the permeability
Permeability (fluid)
Permeability in fluid mechanics and the earth sciences is a measure of the ability of a porous material to allow fluids to pass through it.- Units :...
can be enhanced by pumping high-pressure cold water down an injection well
Injection well
An injection well is a vertical pipe in the ground into which water, other liquids, or gases are pumped or allowed to flow.-Waste disposal: One application is waste water disposal, in which treated waste water is injected into the ground between impermeable layers of rocks to avoid polluting fresh...
into the rock. The injection increases the fluid pressure in the naturally fractured rock, mobilizing shear events that enhance the system's permeability. This process, termed hydro-shearing,
is substantially different from hydraulic tensile fracturing
Hydraulic fracturing
Considerable controversy surrounds the current implementation of hydraulic fracturing technology in the United States. Hydraulic fracturing, or fracking, is the process of utilizing pressurized water, or some other liquid, to fracture rock layers and release petroleum, natural gas, or other...
used in the oil and gas industries.
Water travels through fractures in the rock, capturing the rock's heat until forced out of a second borehole as very hot water. The water's heat is converted into electricity
Electricity
Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...
using either a steam turbine
Steam turbine
A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into rotary motion. Its modern manifestation was invented by Sir Charles Parsons in 1884....
or a binary power plant system. All of the water, now cooled, is injected back into the ground to heat up again in a closed loop
Closed loop
Closed loop may refer to:* A feedback loop, often found in:** Control theory#Closed-loop transfer function, where a closed-loop controller may be used** Electronic feedback loops in electronic circuits** PID controller, a commonly used closed-loop controller...
.
EGS technologies, like hydrothermal geothermal, can function as baseload resources that produce power 24 hours a day, like a fossil fuel
Fossil fuel
Fossil fuels are fuels formed by natural processes such as anaerobic decomposition of buried dead organisms. The age of the organisms and their resulting fossil fuels is typically millions of years, and sometimes exceeds 650 million years...
plant. Unlike hydrothermal, EGS appears to be feasible anywhere in the world, depending on the economic limits of drill depth. Good locations are over deep granite
Granite
Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...
covered by a 3–5 km (1.9–3.1 ) layer of insulating sediments that slow heat loss. EGS wells are expected to have a useful life of 20 to 30 years before the outflow temperature drops about 10 °C (50 °F) and the well becomes uneconomic. If wells are left for 50 to 300 years the temperature will recover.
EGS systems are currently being developed and tested in France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
, the U.S.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
. The largest EGS project in the world is a 25-megawatt demonstration plant currently being developed in Cooper Basin
Cooper Basin
The Cooper Basin is a sedimentary geological basin in Australia. The basin is located mainly in the north-east part of South Australia and extends into south-west Queensland. It is named after the Cooper Creek which is an ephemeral river that runs into Lake Eyre. Part of the Cooper Basin is...
, Australia. Cooper Basin has the potential to generate 5,000–10,000 MW.
EGS industry
Commercial projects are currently either operational or under development in the UK, Australia, the United States, France and Germany.The largest project in the world is being developed in Australia's Cooper Basin by Geodynamics
Geodynamics
Geodynamics is a subfield of geophysics dealing with dynamics of the Earth. It applies physics, chemistry and mathematics to the understanding of how mantle convection leads to plate tectonics and geologic phenomena such as seafloor spreading, mountain building, volcanoes, earthquakes, faulting and...
. The Cooper Basin
Cooper Basin
The Cooper Basin is a sedimentary geological basin in Australia. The basin is located mainly in the north-east part of South Australia and extends into south-west Queensland. It is named after the Cooper Creek which is an ephemeral river that runs into Lake Eyre. Part of the Cooper Basin is...
project has the potential to develop 5–10 GW. Australia now has 33 firms either exploring for, drilling, or developing EGS projects. Australia's industry has been greatly aided by a national Renewable Portfolio Standard
Renewable Portfolio Standard
A Renewable Portfolio Standard is a regulation that requires the increased production of energy from renewable energy sources, such as wind, solar, biomass, and geothermal...
of 25% renewables by 2025, a vibrant Green Energy Credit market, and supportive collaboration between government, academia, and industry.
Germany's now 25 cent/kWh Feed-In Tariff
Feed-in Tariff
A feed-in tariff is a policy mechanism designed to accelerate investment in renewable energy technologies. It achieves this by offering long-term contracts to renewable energy producers, typically based on the cost of generation of each technology...
(FIT) for geothermal energy has led to a surge in geothermal development, despite Germany's relatively poor geothermal resource. The Landau partial EGS project is profitable today under the FIT. Drawing on the success of the Landau project, EGS Energy are developing sites in the UK. The first of these will be built in collaboration with the Eden Project
Eden Project
The Eden Project is a visitor attraction in Cornwall in the United Kingdom, including the world's largest greenhouse. Inside the artificial biomes are plants that are collected from all around the world....
.
The AltaRock Energy
AltaRock Energy
AltaRock Energy Inc., headquartered in Seattle, Washington and having a technology development office in Sausalito, California, is a privately held corporation that focuses on the development of geothermal energy resources and Enhanced Geothermal Systems...
effort is a demonstration project being conducted to prove out the company's proprietary technology at the site of an existing geothermal project owned and operated by NCPA
NCPA
The NCPA is an acronym for several institutions:* National Centre for the Performing Arts, Beijing* National Center for Policy Analysis, Dallas, TX* National Community Pharmacist Association, Alexandria, VA...
in The Geysers
The Geysers
The Geysers is a complex of 22 geothermal power plants, drawing steam from more than 350 wells, located in the Mayacamas Mountains north of San Francisco, California.The largest in the world, the Geysers has...
, and does not include power generation. However, any steam produced by the project will be supplied to NCPA's flash turbines under a long-term contract.
| Project | Type | Country | Size (MW) | Plant Type | Depth (km) | Developer | Status |
|---|---|---|---|---|---|---|---|
| Soultz | R&D | France (EU) | 1.5 | Binary | 4.2 | ENGINE | Operational |
| Desert Peak | R&D | United States | 11–50 | Binary | DOE, Ormat Ormat Industries Ormat Industries Ltd. is a provider of alternative and renewable energy technology. To date the company has installed over 750 power units worldwide... , GeothermEx |
Development | |
| Landau | Commercial | Germany (EU) | 3 | Binary | 3.3 | ? | Operational |
| Paralana (Phase 1) | Commercial | Australia | 7–30 | Binary | 4.1 | Petratherm | Drilling |
| Cooper Basin | Commercial | Australia | 250–500 | Kalina | 4.3 | Geodynamics Geodynamics Geodynamics is a subfield of geophysics dealing with dynamics of the Earth. It applies physics, chemistry and mathematics to the understanding of how mantle convection leads to plate tectonics and geologic phenomena such as seafloor spreading, mountain building, volcanoes, earthquakes, faulting and... |
Drilling |
| The Geysers | Demonstration | United States | (Unknown) | Flash | 3.5 – 3.8 | AltaRock Energy AltaRock Energy AltaRock Energy Inc., headquartered in Seattle, Washington and having a technology development office in Sausalito, California, is a privately held corporation that focuses on the development of geothermal energy resources and Enhanced Geothermal Systems... , NCPA NCPA The NCPA is an acronym for several institutions:* National Centre for the Performing Arts, Beijing* National Center for Policy Analysis, Dallas, TX* National Community Pharmacist Association, Alexandria, VA... |
Suspended (Oct 2009) |
| Bend, Oregon Bend, Oregon Bend is a city in and the county seat of Deschutes County, Oregon, United States, and the principal city of the Bend, Oregon Metropolitan Statistical Area. Bend is Central Oregon's largest city, and, despite its modest size, is the de facto metropolis of the region, owing to the low population... |
Demonstration | United States | (Unknown) | 2 - 3 | AltaRock Energy AltaRock Energy AltaRock Energy Inc., headquartered in Seattle, Washington and having a technology development office in Sausalito, California, is a privately held corporation that focuses on the development of geothermal energy resources and Enhanced Geothermal Systems... , Davenport Newberry, DOE |
Permitting (Mar 2010) | |
| Ogachi | R&D | Japan | (Unknown) | 1.0 – 1.1 | CO2 experiments | ||
| United Downs, Redruth Redruth Redruth is a town and civil parish traditionally in the Penwith Hundred in Cornwall, United Kingdom. It has a population of 12,352. Redruth lies approximately at the junction of the A393 and A3047 roads, on the route of the old London to Land's End trunk road , and is approximately west of... |
Commercial | United Kingdom | 10 MW | Binary | 4.5 | Geothermal Engineering Ltd Geothermal Engineering Ltd. Geothermal Engineering Ltd is a privately-owned British company founded in 2008 specialising in the development of geothermal resources.-United Downs project:... |
Fundraising |
| Eden Project Eden Project The Eden Project is a visitor attraction in Cornwall in the United Kingdom, including the world's largest greenhouse. Inside the artificial biomes are plants that are collected from all around the world.... |
Commercial | United Kingdom | 3 MW | Binary | 3–4 | EGS Energy Ltd. | Fundraising |
Australia
The Australian government has provided research funding for the development of Hot Dry Rock technology.On 30 May 2007, then Australian opposition environmental spokesperson and current Minister for the Environment, Heritage and the Arts
Minister for the Environment, Heritage and the Arts (Australia)
The current Australian Minister for Sustainability, Environment, Water, Population and Communities is Tony Burke, who took over from Peter Garrett . The Minister and department change took effect in the Second Gillard Ministry on 14 September 2010...
Peter Garrett
Peter Garrett
Peter Robert Garrett, AM, MP , is an Australian musician, environmentalist, activist and politician.Garrett was lead singer of the Australian rock band Midnight Oil from 1973 until its disbanding in 2002...
announced that if elected at the 2007 Australian Federal Election, the Australian Labor Party
Australian Labor Party
The Australian Labor Party is an Australian political party. It has been the governing party of the Commonwealth of Australia since the 2007 federal election. Julia Gillard is the party's federal parliamentary leader and Prime Minister of Australia...
would use taxpayer money to subsidise putting the necessary drilling rigs in place. In an interview, he promised:
"There are some technical difficulties and challenges there, but those people who are keen on getting Australia into geothermal say we've got this great access to resource and one of the things, interestingly, that's held them back is not having the capacity to put the drilling plants in place. And so what we intend this $50 million to go towards is to provide one-for-one dollars. Match $1Australian dollarThe Australian dollar is the currency of the Commonwealth of Australia, including Christmas Island, Cocos Islands, and Norfolk Island, as well as the independent Pacific Island states of Kiribati, Nauru and Tuvalu...
from us, $1 from the industry so that they can get these drilling rigs on to site and really get the best sites identified and get the industry going."
European Union
The EU's EGS R&D project at Soultz-sous-ForêtsSoultz-sous-Forêts
Soultz-sous-Forêts is a commune in the Bas-Rhin department in Alsace in north-eastern France.It is the site of the European Hot Dry Rocks energy research project.-References:*...
, France, has recently connected its 1.5 MW demonstration plant to the grid. The Soultz project has explored the connection of multiple stimulated zones and the performance of triplet well configurations (1 injector/2 producers).
Induced seismicity in Basel
Induced seismicity in Basel
Induced seismicity in Basel led to suspension of its hot dry rock enhanced geothermal systems project. A seismic-hazard evaluation was then conducted, resulting in the cancellation of the project in December 2009. Basel, Switzerland sits atop a historically active fault and most of the city was...
led to the cancellation of the EGS project there.
The Portuguese government awarded, in December 2008, an exclusive license to Geovita Ltd to prospect and explore geothermal energy in one of the best areas in continental Portugal. An area of about 500 square kilometers is being studied by Geovita together with the Earth Sciences department of the University of Coimbra's Science and Technology faculty, and the installation of an Enhanced Geothermal System (EGS) is foreseen.
United Kingdom
Cornwall is set to host a 3MW demonstration project, based at the Eden Project, that could pave the way for a series of 50-MW commercial-scale geothermal power stations in suitable areas across the country.A commercial-scale project near Redruth is also planned. The plant, which has been granted planning permission, would generate 10 MW of electricity and 55 MW of thermal energy and is scheduled to become operational in 2013–2014.
Early days — Fenton Hill
The United States pioneered the first EGS effort — then termed Hot Dry Rock — at Fenton Hill, New Mexico with a project run by the federal Los Alamos Laboratory. It was the first attempt anywhere to make a deep, full-scale HDR reservoir, and efforts there spanned 1974 through 1992, in two phases. Ultimately, the project was unable to generate net energy and was terminated.Working at the edges—using EGS technology to improve hydrothermal resources
EGS funding languished for the next few years, and by the next decade, US efforts focused on the less ambitious goal of improving the productivity of existing hydrothermal resources. According to the fiscal year 2004 Budget Request to Congress from DOE's Office of Energy Efficiency and Renewable Energy,In fiscal year 2002, this vision translated into completing "preliminary designs for five competitively selected projects employing EGS technology," and the selection of one project for "full-scale development" at the Coso Hot Springs geothermal field at the US Naval Weapons Air Station in China Lake, California, and two additional projects for "preliminary analysis from a new solicitation" at Desert Peak in Nevada and Glass Mountain in California. Funding for this effort totaled $1.5 million.
In fiscal year 2003, $3.5 million was appropriated to launch the Coso project, with the aim of improving the permeability of an existing poorly performing well, and to complete the conceptual design and feasibility studies at the Desert Peak and Glass Mountain sites.
The fiscal year 2004 request for $6 million was to "[s]tep up work on EGS cost-shared projects' at the three sites, to include "drilling and reservoir stimulation experiments" at one and drilling a production well at another.
The US Department of Energy USDOE issued two Funding Opportunity Announcement
Funding Opportunity Announcement
A funding opportunity announcement is a notice in Grants.gov of a federal grant funding opportunity.Funding opportunity announcements can be found at Grants.gov/FIND and this website lets organizations apply for grants for over 1,000 grant programs from 26 federal agencies.Each FOA includes...
s (FOAs) on March 4, 2009 for enhanced geothermal systems (EGS). Together, the two FOAs offer up to $84 million over six years, including $20 million in fiscal year 2009 funding, although future funding is subject to congressional appropriations.
The DOE followed up with another FOA on March 27, 2009, of stimulus funding from the American Reinvestment and Recovery Act for $350 million, including $80 million aimed specifically at EGS proejcts,
Induced seismicity
Some induced seismicity is inevitable and expected in EGS, which involves pumping fluids at pressure to enhance or create permeability through the use of hydro-shearing techniques. In contrast to induction of tensile failure, the purpose of hydraulic fracturing used in the oil and gas industries, EGS seeks to induce relatively small shear failure of the rock's existing joint set to create an optimum reservoir for the transfer of heat from the rock to the water in order to produce steam. Seismicity events at the Geysers geothermal field in California have been strongly correlated with injection data.The case of induced seismicity in Basel
Induced seismicity in Basel
Induced seismicity in Basel led to suspension of its hot dry rock enhanced geothermal systems project. A seismic-hazard evaluation was then conducted, resulting in the cancellation of the project in December 2009. Basel, Switzerland sits atop a historically active fault and most of the city was...
merits special mention; it led the city (which is a partner) to suspend the project and conduct a seismic hazard evaluation, which resulted in the cancellation of the project in December 2009.
Risks associated with "hydrofracturing induced seismicity are low compared to that of natural earthquakes, and can be reduced by careful management and monitoring" and "should not be regarded as an impediment to further development of the Hot Rock geothermal energy resource".
CO2 EGS
The recently established Center for Geothermal Energy Excellence at the University of Queensland has been awarded $18.3 million (AUS) for EGS research, a large portion of which will be used to develop CO2 EGS technologies.Research conducted at Los Alamos National Laboratories and Lawrence Berkeley National Laboratories examined the use of supercritical CO2
Supercritical carbon dioxide
Supercritical carbon dioxide is a fluid state of carbon dioxide where it is held at or above its critical temperature and critical pressure.Carbon dioxide usually behaves as a gas in air at STP or as a solid called dry ice when frozen...
, instead of water, as the geothermal working fluid, with favorable results. CO2 has numerous advantages for EGS:
-
- Greater power output
- Minimized parasitic losses from pumping and cooling
- Carbon sequestration
- Minimized water use
EGS potential in the United States
- Resource size: The report calculated the United States total EGS resources from 3–10 km of depth to be over 13,000 zettajoulesJouleThe joule ; symbol J) is a derived unit of energy or work in the International System of Units. It is equal to the energy expended in applying a force of one newton through a distance of one metre , or in passing an electric current of one ampere through a resistance of one ohm for one second...
, of which over 200 ZJ would be extractable, with the potential to increase this to over 2,000 ZJ with technology improvements — sufficient to provide all the world's current energy needs for several millenniaMillenniumA millennium is a period of time equal to one thousand years —from the Latin phrase , thousand, and , year—often but not necessarily related numerically to a particular dating system....
. The report found that total geothermal resources, including hydrothermal and geo-pressured resources, to equal 14,000 ZJ — or roughly 140,000 times the total U.S. annual primary energy use in 2005. - Development potential: With a modest R&D investment of $1 billion over 15 years (or the cost of one coal power plant), the report estimated that 100 GWe (gigawatts of electricity) or more could be installed by 2050 in the United States. The report further found that the "recoverable" resource (that accessible with today's technology) to be between 1.2–12.2 TW for the conservative and moderate recovery scenarios respectively.
- Cost: The report found that EGS could be capable of producing electricity for as low as 3.9 cents/kWh. EGS costs were found to be sensitive to four main factors: 1) Temperature of the resource, 2) Fluid flow through the system measured in liters/second, 3) Drilling costs, and 4) Power conversion efficiency.
See also
- CaprockCaprockThe Caprock is a region in the Panhandle of Texas . It is the land to the west of the Caprock Escarpment, which separates it from plains stretching to the east at a much lower elevation....
- Rosemanowes QuarryRosemanowes QuarryRosemanowes Quarry, near Penryn, Cornwall, United Kingdom, was the site of an early experiment in extracting geothermal energy from the earth using hot dry rock technology.-Geothermal energy research project:...
- Geothermal energy in the United StatesGeothermal energy in the United StatesGeothermal energy in the United States continues to be an area of considerable activity. In 2010, the United States led the world in geothermal electricity production with 3,086 megawatts of installed capacity from 77 power plants; the largest group of geothermal power plants in the world is...
- Geothermal energy exploration in Central AustraliaGeothermal energy exploration in Central AustraliaGeothermal power in Australia is little used but growing. There are known and potential locations near the centre of the country that have been shown to contain hot granites at depth which hold good potential for development of geothermal energy...
- Geothermal explorationGeothermal explorationGeothermal Exploration is a multidisciplinary process used to explore the subsurface in search of viable active geothermal regions with the ultimate goal of building a geothermal power plant, where hot fluids drive turbines to create electricity...
External links
- EERE:
- Geothermal investment rocks says DLA Phillips Fox
- 20 slide presentation inc geothermal maps of Australia
- MEGSorg
- EGS at Google.orgGoogle.orgGoogle.org is the charitable arm of Internet search engine company Google.The organization has committed over $100 million in investments and grants as of May 2010. To fund the organization, Google granted them 3 million shares during their initial public offering. As of August 2011, Google.org's 3...