Product Code Database
Geothermal power is electrical power generated from geothermal energy. Technologies in use include dry steam power stations, flash steam power stations and binary cycle power stations. Geothermal electricity generation is currently used in 26 countries,Geothermal Energy Association. Geothermal Energy: International Market Update May 2010, p. 4-6. (2025). 9780123971784, Newnes. ISBN 9780123971784 while geothermal heating is in use in 70 countries.
As of 2019, worldwide geothermal power capacity amounts to 15.4 (GW), of which 23.9% (3.68 GW) are installed in the United States. International markets grew at an average annual rate of 5 percent over the three years to 2015, and global geothermal power capacity is expected to reach 14.5–17.6 GW by 2020. Based on current geologic knowledge and technology the Geothermal Energy Association (GEA) publicly discloses, the GEA estimates that only 6.9% of total global potential has been tapped so far, while the IPCC reported geothermal power potential to be in the range of 35 GW to 2 terawatt. Countries generating more than 15 percent of their electricity from geothermal sources include El Salvador, Kenya, the Philippines, Iceland, New Zealand, and Costa Rica. Indonesia has an estimated potential of 29 GW of geothermal energy resources, the largest in the world; in 2017, its installed capacity was 1.8 GW.
Geothermal power is considered to be a sustainable, renewable energy source of energy because the heat extraction is small compared with the Earth's heat content. The greenhouse gas emissions of geothermal electric stations average 45 grams of carbon dioxide per kilowatt-hour of electricity, or less than 5% of those of conventional coal-fired plants.Moomaw, W., P. Burgherr, G. Heath, M. Lenzen, J. Nyboer, A. Verbruggen, 2011: Annex II: Methodology. In IPCC: Special Report on Renewable Energy Sources and Climate Change Mitigation (ref. page 10)
As a source of renewable energy for both power and heating, geothermal has the potential to meet 3 to 5% of global demand by 2050. With economic , it is estimated that by 2100 it will be possible to meet 10% of global demand with geothermal power.
In 1958, New Zealand became the second major industrial producer of geothermal electricity when its Wairakei station was commissioned. Wairakei was the first station to use flash steam technology. Over the past 60 years, net fluid production has been in excess of 2.5 km3. Subsidence at Wairakei-Tauhara has been an issue in a number of formal hearings related to environmental consents for expanded development of the system as a source of renewable energy.
In 1960, Pacific Gas and Electric began operation of the first successful geothermal electric power station in the United States at The Geysers in California. The original turbine lasted for more than 30 years and produced 11 Megawatt net power.
An organic fluid based binary cycle power station was first demonstrated in 1967 in the Soviet Union and later introduced to the United States in 1981, following the 1970s energy crisis and significant changes in regulatory policies. This technology allows the use of temperature resources as low as . In 2006, a binary cycle station in Chena Hot Springs, Alaska, came on-line, producing electricity from a record low fluid temperature of .
Geothermal electric stations have until recently been built exclusively where high-temperature geothermal resources are available near the surface. The development of binary cycle power plants and improvements in drilling and extraction technology may enable enhanced geothermal systems over a much greater geographical range. Demonstration projects are operational in Landau-Pfalz, Germany, and Soultz-sous-Forêts, France, while an earlier effort in Basel, Switzerland was shut down after it triggered earthquakes. Other demonstration projects are under construction in Australia, the United Kingdom, and the United States of America.
The thermal efficiency of geothermal electric stations is low, around 7 to 10%, (2025). 9780470510278, John Wiley & Sons, Ltd. ISBN 9780470510278 because geothermal fluids are at a low temperature compared with steam from boilers. By the laws of thermodynamics this low temperature limits the efficiency of cycle efficiency in extracting useful energy during the generation of electricity. Exhaust heat is wasted, unless it can be used directly and locally, for example in greenhouses, timber mills, and district heating. The efficiency of the system does not affect operational costs as it would for a coal or other fossil fuel plant, but it does factor into the viability of the station. In order to produce more energy than the pumps consume, electricity generation requires high-temperature geothermal fields and specialized heat cycles. Because geothermal power does not rely on variable sources of energy, unlike, for example, wind or solar, its capacity factor can be quite large – up to 96% has been demonstrated.
However the global average capacity factor was 74.5% in 2008, according to the IPCC.Goldstein, B., G. Hiriart, R. Bertani, C. Bromley, L. Gutiérrez-Negrín, E. Huenges, H. Muraoka, A. Ragnarsson, J. Tester, V. Zui (2011) "Geothermal Energy" . In IPCC Special Report on Renewable Energy Sources and Climate Change Mitigation, Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA Geothermal Energy. p. 404.
Electricity generation requires high-temperature resources that can only come from deep underground. The heat must be carried to the surface by fluid circulation, either through , , hydrothermal circulation, , drilled water wells, or a combination of these. This circulation sometimes exists naturally where the crust is thin: magma conduits bring heat close to the surface, and hot springs bring the heat to the surface. If a hot spring is not available, a well must be drilled into a hot aquifer. Away from tectonic plate boundaries the geothermal gradient is 25 to 30 °C per kilometre (70 to 85 °F per mile) of depth in most of the world, so wells would have to be several kilometres deep to permit electricity generation. The quantity and quality of recoverable resources improves with drilling depth and proximity to tectonic plate boundaries.
In ground that is hot but dry, or where water pressure is inadequate, injected fluid can stimulate production. Developers bore two holes into a candidate site, and fracture the rock between them with explosives or high-pressure water. Then they pump water or liquefied carbon dioxide down one borehole, and it comes up the other borehole as a gas. This approach is called hot dry rock geothermal energy in Europe, or enhanced geothermal systems in North America. Much greater potential may be available from this approach than from conventional tapping of natural aquifers.
Estimates of the electricity generating potential of geothermal energy vary from 35 to 2000 GW depending on the scale of investments. This does not include non-electric heat recovered by co-generation, geothermal heat pumps and other direct use. A 2006 report by the Massachusetts Institute of Technology (MIT) that included the potential of enhanced geothermal systems estimated that investing US$1 billion in research and development over 15 years would allow the creation of 100 GW of electrical generating capacity by 2050 in the United States alone. The MIT report estimated that over would be extractable, with the potential to increase this to over 2,000 ZJ with technology improvements – sufficient to provide all the world's present energy needs for several millennium.
At present, geothermal wells are rarely more than deep. Upper estimates of geothermal resources assume wells as deep as . Drilling near this depth is now possible in the petroleum industry, although it is an expensive process. The deepest research well in the world, the Kola Superdeep Borehole (KSDB-3), is deep. Wells drilled to depths greater than generally incur drilling costs in the tens of millions of dollars. The technological challenges are to drill wide bores at low cost and to break larger volumes of rock.
Geothermal power is considered to be sustainable because the heat extraction is small compared to the Earth's heat content, but extraction must still be monitored to avoid local depletion. Although geothermal sites are capable of providing heat for many decades, individual wells may cool down or run out of water. The three oldest sites, at Larderello, Wairakei, and the Geysers have all reduced production from their peaks. It is not clear whether these stations extracted energy faster than it was replenished from greater depths, or whether the aquifers supplying them are being depleted. If production is reduced, and water is reinjected, these wells could theoretically recover their full potential. Such mitigation strategies have already been implemented at some sites. The long-term sustainability of geothermal energy has been demonstrated at the Larderello field in Italy since 1913, at the Wairakei field in New Zealand since 1958, and at the Geysers field in California since 1960.
Al Gore said in The Climate Project Asia Pacific Summit that Indonesia could become a super power country in electricity production from geothermal energy. In 2013 the publicly owned electricity sector in India announced a plan to develop the country's first geothermal power facility in the landlocked state of Chhattisgarh.
Geothermal power in Canada has high potential due to its position on the Pacific Ring of Fire. The region of greatest potential is the Canadian Cordillera, stretching from British Columbia to the Yukon, where estimates of generating output have ranged from 1,550 MW to 5,000 MW.
The geography of Japan is advantageous for geothermal power production. Japan has numerous that could provide fuel for geothermal power plants, but a massive investment in Japan's infrastructure would be necessary. (2025). 9781137442888, Palgrave Macmillan US. ISBN 9781137442888
The following table lists these data for each country:
Data are for the year 2021. Data are sourced from the EIA.Under "Electricity" select "More Electricity data". At the top right, under Generation select 'Total' and 'Geothermal' and under Capacity select 'Geothermal'. Choose the two most recent years. Only includes countries with more than 0.01 TWh of generation. Links for each location go to the relevant geothermal power page, when available.
| 71% |
| 71% |
| 80% |
| 64% |
| 73% |
| 70% |
| 86% |
| 82% |
| 68% |
| 47% |
| 72% |
| 70% |
| 88% |
| 58% |
| 69% |
| 82% |
| 94% |
| 73% |
| 91% |
| 62% |
| 70% |
| 95% |
| 55% |
| 85% |
Stations that experience high levels of acids and volatile chemicals are usually equipped with emission-control systems to reduce the exhaust. Geothermal stations can also inject these gases back into the earth as a form of carbon capture and storage, such as in New Zealand and in the CarbFix project in Iceland.
Other stations, like the Kızıldere geothermal power plant, exhibit the capability to use geothermal fluids to process carbon dioxide gas into dry ice at two nearby plants, resulting in very little environmental impact.
In addition to dissolved gases, hot water from geothermal sources may hold in solution trace amounts of toxic chemicals, such as mercury, arsenic, boron, antimony, and salt. These chemicals come out of solution as the water cools, and can cause environmental damage if released. The modern practice of injecting geothermal fluids back into the Earth to stimulate production has the side benefit of reducing this environmental risk.
Station construction can adversely affect land stability. Subsidence has occurred in the Wairakei field in New Zealand. Enhanced geothermal systems can trigger earthquakes due to water injection. The project in Basel, Switzerland was suspended because more than 10,000 seismic events measuring up to 3.4 on the Richter Scale occurred over the first 6 days of water injection. The risk of geothermal drilling leading to Tectonic uplift has been experienced in Staufen im Breisgau.
Geothermal has minimal land and freshwater requirements. Geothermal stations use 404 square meters per gigawatt-hour versus 3,632 and 1,335 square meters for coal facilities and wind farms respectively. They use 20 litres of freshwater per MWh versus over 1000 litres per MWh for nuclear, coal, or oil.
Local climate cooling is possible as a result of the work of the geothermal circulation systems. However, according to an estimation given by Leningrad Mining Institute in 1980s, possible cool-down will be negligible compared to natural climate fluctuations.
While volcanic activity produces geothermal energy, it is also risky. the Puna Geothermal Venture has still not returned to full capacity after the 2018 lower Puna eruption.
Research suggests in-reservoir storage could increase the economic viability of enhanced geothermal systems in energy systems with a large share of variable renewable energy sources.
Geothermal power is highly scalable: a small power station can supply a rural village, though initial capital costs can be high.
The most developed geothermal field is the Geysers in California. In 2008, this field supported 15 stations, all owned by Calpine, with a total generating capacity of 725 MW.
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