Geothermal energy is thermal energy extracted from the Earth's crust. It combines energy from the formation of the planet and from radioactive decay. Geothermal energy has been exploited as a source of heat and/or electric power for millennia.
Geothermal energy was first used for electric power production in the United States in 1960. The Geysers in Sonoma and Lake counties, California was developed into the largest geothermal steam electrical plant in the world, at 1,517 megawatts. Other geothermal steam fields operate in the western US and Alaska.
The Kawerau Power Station is a 100-megawatt geothermal power plant located just outside the town of Kawerau in the Bay of Plenty Region of New Zealand. The power station is situated within the Kawerau geothermal field, which is part of the Taupo Volcanic Zone. Completed in July 2008 by Mighty River Power at a cost of NZ$300 million, the plant's capacity proved greater than expected. The station is the largest single-generator geothermal plant in New Zealand.
The Geysers is the world's largest geothermal field, containing a complex of 18 geothermal power plants, drawing steam from more than 350 wells, located in the Mayacamas Mountains approximately 72 miles (116 km) north of San Francisco, California.
The Wairakei Power Station is a geothermal power station near the Wairakei Geothermal Field in New Zealand. Wairakei lies in the Taupō Volcanic Zone.
The Poihipi Power Station is a geothermal power station owned and operated by Contact Energy. It is located on Poihipi Road near Taupō in New Zealand.
Mount Malinao is a potentially active stratovolcano located in the Bicol Region of the Philippines. The volcano displays strong fumarolic activity which is harnessed for generating electricity. Located on its slope is Tiwi Geothermal Power Plant, one of the first geothermal energy plant commissioned in the country.
Geothermal power is very cost-effective in the Great Rift Valley of Kenya, East Africa. As of 2023, Kenya has 891.8 MW of installed geothermal capacity. Kenya was the first African country to build geothermal energy sources. The Kenya Electricity Generating Company, which is 74% state-owned, has built several plants to exploit the Olkaria geothermal resource; Olkaria I, Olkaria II, Olkaria IV, Olkaria V, and Wellhead generation plants, with a third private plant Olkaria III. Additionally, a pilot wellhead plant of 2.5 MW has been commissioned at Eburru and two small scale plants have been built by the Oserian Development Company to power their rose farm facilities with a total of 4 MW.
Chile represents one of the largest undeveloped geothermal areas of the world. Despite Chile's good economic performance in the late 1980s and 1990s, geothermal energy did not develop, and Chile has been surpassed by other Latin American countries such as El Salvador and Costa Rica in terms of geothermal development and technology. Currently, Chile has only one geothermal power plant.
The Hellisheiði Power Station is the eighth-largest geothermal power station in the world and largest in Iceland. The facility is located in Hengill, southwest Iceland, 11 km (7 mi) from the Nesjavellir Geothermal Power Station. The plant has a capacity of 303 MW of electricity and 200 MWth of hot water for Reykjavik's district heating. The power station is owned and operated by ON Power, a subsidiary of Reykjavík Energy.
Ngatamariki is a geothermal power station commissioned in 2013 and operated by Mercury Energy. It is located approximately 17 km north east of Taupō and was constructed well under the budget of $475 million.
The Malitbog Geothermal Power Station is a 232.5 MW geothermal power plant or an earth steam turbined electric generator—the world's largest geothermal power plant under one roof located in Malitbog, Kananga, Leyte, Philippines. The power plant is one of four operating in the Leyte Geothermal Production Field. The power plants serve 10 million households in Visayas with an average of 160 kiloWatthour per Household of 3 per month. The other 7 million is served by the Panlipin-on Geothermal Power of 100 Megawatts.
Energy Development Corporation is the largest producer of geothermal energy in the Philippines and the second largest in the world. It is involved in alternative energy projects, including geothermal, hydroelectric and wind energy projects. The company was formerly owned by the Philippine National Oil Company, a state corporation owned by the Republic of the Philippines engaged in the exploration of resources, production of energy and distribution of power supply to smaller electricity distributor. EDC was privatized and acquired by the Lopez Group as part of its energy and power supply utility business units.
The Mount Apo Geothermal Power Plant is a geothermal power station located in Barangay Ilomavis, Kidapawan, Cotabato. Drawing steam from the Mindanao Geothermal Production Field, the power station is situated near the foot of Mount Apo and has a power output of 106 MW. It is currently part of the Mindanao Grid that supplies electricity to Kidapawan and Davao Region.
The Aluto–Langano Geothermal Power Station, also known as Aluto Langano Geothermal Power Station, is the only geothermal power station in Ethiopia.
The Puna Geothermal Venture (PGV) is a geothermal energy power plant on the island of Hawaii, the largest island in the state of Hawaii. The plant was shut down shortly after the start of the May 2018 lower Puna eruption, and resumed power generation in November 2020. The eruption had caused lava to flow over a PGV power substation, a warehouse and at least three geothermal wells that had been preventatively quenched and capped when lava fountains erupted nearby, eventually also cutting off road access.
The Tiwi Geothermal Power Plant is a 234-MW geothermal power station in Tiwi, Albay, Philippines.
The Palinpinon Geothermal Power Plant is a 192.5-MW complex of geothermal power stations in Valencia, Negros Oriental, Philippines
