El vicepresidente senior de Alstom Power Thermal Products, Guy Chardon, declaró que este nuevo proyecto "supone la vuelta de Alstom al mercado geotérmico, después de que en el año 2000 construyera cuatro unidades de 25 megavatios (MW) en Los Azufres, México". "Los productos geotérmicos de Alstom se basan en soluciones probadas del grupo, tales como las turbinas de vapor, los generadores, las bombas y los sistemas de control, para ampliar la oferta en el campo de las energías renovables", añadió Chardon.
La central de Los Humeros II tendrá una capacidad neta garantizada de 25 MW. Según el acuerdo, Alstom se hará cargo de la ingeniería, aprovisionamiento y construcción. Asimismo, se encargará de la obra civil, la gestión y liderazgo del proyecto, los equipos electromecánicos (BoP) y la supervisión de la obra. La turbina se fabricará en las instalaciones de Alstom en Morelia, en el Estado de Michoacán.
México es el cuarto productor mundial de electricidad geotérmica, por detrás de Estados Unidos, Filipinas e Indonesia. El proyecto de Los Humeros II supone el regreso de Alstom al mercado en un momento de crecimiento de la energía geotérmica, que está presente en más de 70 países.
Además del contrato adjudicado en el año 2000 para la construcción de las cuatro unidades de 25MW en la central geotérmica de Los Azufres, Alstom firmó también un contrato en 1998 para la creación de dos unidades de 5,5 MW en la central geotérmica de Las Tres Vírgenes, en Baja California Sur.
Alstom es líder mundial en infraestructuras para la generación de energía y transporte ferroviario y un referente en tecnologías innovadoras y respetuosas con el medio ambiente. Alstom construye los trenes más rápidos del mundo y el metro automático de mayor capacidad. Alstom suministra soluciones integradas y completas para centrales de generación de energía, además de servicios asociados, para una gran variedad de fuentes de energía, como la eólica. Alstom emplea a más de 81.000 personas en 70 países.
Energía geotérmica
La energía geotérmica es aquella energía que puede ser obtenida por el hombre mediante el aprovechamiento del calor del interior de la Tierra. El calor del interior de la Tierra se debe a varios factores, entre los que caben destacar el gradiente geotérmico o el calor radiogénico. Geotérmico viene del griego geo, "Tierra", y thermos, "calor"; literalmente "calor de la Tierra".
Se obtiene energía geotérmica por extracción del calor interno de la Tierra. En áreas de aguas termales muy calientes a poca profundidad, se perfora por fracturas naturales de las rocas basales o dentro de rocas sedimentarios. El agua caliente o el vapor pueden fluir naturalmente, por bombeo o por impulsos de flujos de agua y de vapor (flashing). El método a elegir depende del que en cada caso sea económicamente rentable. Un ejemplo, en Inglaterra, fue el "Proyecto de Piedras Calientes HDR" (sigla en inglés: HDR, Hot Dry Rocks), abandonado después de comprobar su inviabilidad económica en 1989. Los programas HDR se están desarrollando en Australia, Francia, Suiza, Alemania. Los recursos de magma (rocas fundidas) ofrecen energía geotérmica de altísima temperatura, pero con la tecnología existente no se pueden aprovechar económicamente esas fuentes.
En la mayoría de los casos la explotación debe hacerse con dos pozos (o un número par de pozos), de modo que por uno se obtiene el agua caliente y por otro se vuelve a reinyectar en el acuífero, tras haber enfriado el caudal obtenido. Las ventajas de este sistema son múltiples:
* Hay menos probabilidades de agotar el yacimiento térmico, puesto que el agua reinyectada contiene todavía una importante cantidad de energía térmica.
* Tampoco se agota el agua del yacimiento, puesto que la cantidad total se mantiene.
* Las posibles sales o emisiones de gases disueltos en el agua no se manifiestan al circular en circuito cerrado por las conducciones, lo que evita contaminaciones.
Tipos de yacimientos geotérmicos según la temperatura del agua
* Energía geotérmica de alta temperatura. La energía geotérmica de alta temperatura existe en las zonas activas de la corteza. Esta temperatura está comprendida entre 150 y 400 ºC, se produce vapor en la superficie y mediante una turbina, genera electricidad. Se requieren varios condiciones para que se dé la posibilidad de existencia de un campo geotérmico: una capa superior compuesta por una cobertura de rocas impermeables; un acuífero, o depósito, de permeabilidad elevada, entre 0,3 y 2 km de profundidad; suelo fracturado que permite una circulación de fluidos por convección, y por lo tanto la trasferencia de calor de la fuente a la superficie, y una fuente de calor magmático, entre 3 y 15 km de profundidad, a 500-600 ºC. La explotación de un campo de estas características se hace por medio de perforaciones según técnicas casi idénticas a las de la extracción del petróleo.
* Energía geotérmica de temperaturas medias. La energía geotérmica de temperaturas medias es aquella en que los fluidos de los acuíferos están a temperaturas menos elevadas, normalmente entre 70 y 150 ºC. Por consiguiente, la conversión vapor-electricidad se realiza con un rendimiento menor, y debe explotarse por medio de un fluido volátil. Estas fuentes permiten explotar pequeñas centrales eléctricas, pero el mejor aprovechamiento puede hacerse mediante sistemas urbanos reparto de calor para su uso en calefacción y en refrigeración (mediante máquinas de absorción).
* Energía geotérmica de baja temperatura. La energía geotérmica de temperaturas bajas es aprovechable en zonas más amplias que las anteriores; por ejemplo, en todas las cuencas sedimentarias. Es debida al gradiente geotérmico. Los fluidos están a temperaturas de 50 a 70 ºC.
* Energía geotérmica de muy baja temperatura. La energía geotérmica de muy baja temperatura se considera cuando los fluidos se calientan a temperaturas comprendidas entre 20 y 50 ºC. Esta energía se utiliza para necesidades domésticas, urbanas o agrícolas.
Las fronteras entre los diferentes tipos de energías geotérmicas es arbitraria; si se trata de producir electricidad con un rendimiento aceptable la temperatura mínima está entre 120 y 180 ºC, pero las fuentes de temperatura más baja son muy apropiadas para los sistemas de calefacción urbana.
Ventajas
1. Es una fuente que evita la dependencia energética del exterior.
2. Los residuos que produce son mínimos y ocasionan menor impacto ambiental que los originados por el petróleo, carbón…
Inconvenientes
1. En ciertos casos emisión de ácido sulfhídrico que se detecta por su olor a huevo podrido, pero que en grandes cantidades no se percibe y es letal.
2. En ciertos casos, emisión de CO2, con aumento de efecto invernadero; es inferior al que se emitiría para obtener la misma energía por combustión.
3. Contaminación de aguas próximas con sustancias como arsénico o amoníaco.
4. Contaminación térmica.
5. Deterioro del paisaje.
6. No se puede transportar (como energía primaria).
7. No está disponible más que en determinados lugares.
Se produjo energía eléctrica geotérmica por vez primera en Larderello, Italia, en 1904. Desde ese tiempo, el uso de la energía geotérmica para electricidad ha crecido mundialmente a cerca de 8.000 megavatios.
Tipos de plantas eléctricas
Tres tipos se usan para generar potencia de la energía geotérmica:
* vapor seco
* flash
* binario.
En las plantas a vapor seco se toma el vapor de las fracturas en el suelo y se pasa directamente por una turbina, para mover un generador. En las plantas flash se obtiene agua muy caliente, generalmente a más de 200 °C, y se separa la fase vapor en separadores vapor/agua, y se mueve una turbina con el vapor. En las plantas binarias, el agua caliente fluye a través de intercambiadores de calor, haciendo hervir un fluido orgánico que luego hace girar la turbina. El vapor condensado y el fluido remanente geotérmico de los tres tipos de plantas se vuelve a inyectar en la roca caliente para hacer más vapor. El calor de la tierra es considerado como una energía sostenible. El calor de la Tierra es tan vasto que solo se puede extraer una fracción, por lo que el futuro es relevante para las necesidades de energía mundial.
"Los Géiseres" (The Geysers), a 145 km al norte de San Francisco es la planta más grande de las que funcionan con vapor seco. La planta comenzó a funcionar en 1960 con 1.360 MW de capacidad instalada y genera 1.000 MW netos. La "Calpine Corporation" es dueña de 19 de las 21 plantas en The Geysers, y en EE UU es el productor de energía renovable geotérmica más grande. Las otras dos plantas son propiedad de la "Northern California Power Agency" y "Santa Clara Electric". Cada actividad de una planta geotérmica afecta a todas las vecinas, por lo que la propiedad consolidada de "The Geysers" ha sido beneficioso debido a la operación sincrónica y cooperativa, dejando de lado cualquier ventaja unitaria de corto término. Los Geiseres se recargan por inyección de los efluentes cloacales de las ciudades de Santa Rosa y de Lake County, California con plantas depuradoras del agua residual. Anteriormente, esos efluentes cloacales se arrojaban a ríos y arroyos. Ahora se introducen en el yacimiento geotérmico, recargándolo para producir vapor.
Otra gran cuenca geotérmica es el centro sur de California, en la orilla sudeste del Mar Salton Salton Sea, cerca de las ciudades de Niland y de Calipatria. Desde 2001, hay 15 plantas geotérmicas produciendo electricidad. CalEnergy es dueña de 8 plantas y el resto son de varias compañías. La producción total de las plantas es de 570 MW.
En las provincias geológicas "Basin" y "Range" en Nevada, sudeste de Oregón, sudoeste de Idaho, Arizona y oeste de Utah se está produciendo un rápido desarrollo geotermal. En los 1980shabía varias plantas pequeñas, cuando los precios de la energía eran altos. En los 1990s bajó el costo de la energía, no haciéndose desde entonces nuevas instalaciones. En los 2000s resurge la industria geotérmica por las nuevas subidas del precio de la energía: plantas en Nevada "Steamboat", "Brady/Desert Peak", "Dixie Valley", "Soda Lake", "Stillwater" y Beowawe" que producen conjuntamente 235 MW. Y más empresas están preparando nuevos proyectos. La energía geotérmica es muy eficiente en costos en la zona del Rift, África. KenGen de Kenya ha hecho dos plantas: Olkaria I (45 MW) y Olkaria II (65 MW), y se prevé una tercera planta privada, Olkaria III (48 MW), explotada por la Cía. israelí, especializada en geotermia, Ormat. Hay planes para incrementar la capacidad de producción en otros 576 MW para 2017, cubriendo el 25 % de las necesidades eléctricas de Kenya, y reduciendo la dependencia del combustible importado.
Se genera electricidad "geotérmica" en más de 20 países. Islandia produce el 17% de sus necesidades de la energía geotérmica, EE. UU., Italia, Francia, Nueva Zelandia, México, Nicaragua, Costa Rica, Rusia, Filipinas (1.931 MW, 2º tras EE UU, 27 % de su electricidad), Indonesia y Japón. Canadá, que tiene 30.000 instalaciones de energía geotérmica para dar calefacción domiciliaria y a comercios, tiene una planta experimental geotérmico-eléctrica en la Montaña Meager Mountain, área de Pebble Creek en la Columbia Británica, con 100 MW en futuro próximo.
Inyección de agua
En varios sitios, ha ocurrido que los depósitos de magma se agotaron, cesando de dar energía geotérmica, quizás ayudado por la inyección del agua residual fría, en la recarga del acuífero caliente. O sea que la recarga por reinyección, puede enfriar el recurso, a menos que se haga una gestión cuidadosa. En al menos una localidad, el enfriamiento fue resultado de pequeños pero frecuentes terremotos.
Extinción del calor
Así como hay yacimientos geotérmicos capaces de proporcionar energía durante muchas décadas, otros pueden agotarse y enfriarse. En un informe, el gobierno de Islandia dice: debe entenderse que la energía geotérmica no es estrictamente renovable en el mismo sentido que la hidráulica.
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Alstom-built geothermal power plant will provide cost-effective, reliable and environmentally friendly electricity to Mexico
15 May 2009
The project will reduce the country’s CO2 emissions by 230,000 tonnes per year, further establishing Alstom’s role as a clean power producer.
Alstom has won a €45 million turnkey contract with Mexico’s Comisión Federal de Electricidad (CFE) to supply a geothermal power plant including key equipment in Mexico.
When completed in October 2011, the Los Humeros II geothermal power plant will supply reliable, cost-effective and environmentally friendly electricity to Mexico’s eastern Puebla state.
“Los Humeros II geothermal project represents the return of Alstom to the geothermal market since 2000 when four units of 25MW were built in Los Azufres, Mexico” said Guy Chardon, Senior Vice President Alstom Power Thermal Products. “Alstom’s Geothermal line builds on the group’s proven solutions such as steam turbines, generators, pumps and control systems to expand its renewable offering to its customers.”
Geothermal steam is located some 2-3 km beneath the earth’s surface and extracted to feed the turbine of a geothermal power plant. The resulting energy is low in greenhouse gases, provides base load energy* and is immune to fluctuations in fuel prices, since it requires no fuel.
Los Humeros II and its associated facilities will have a guaranteed net capacity of 25 MW. Alstom will supply the complete engineering, procurement and construction (EPC), including the geothermal steam turbines, air cooled turbogenerator, turbine control and digital control system, a high voltage electric 115kv substation, a direct contact condenser, hotwell pumps, cooling tower, fire protection system, HVAC, civil works, project management and leadership, mechanical BoP engineering and site supervision. The turbine will be produced at Alstom’s local manufacturing facility in the municipality of Morelia, Michoacan state.
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Geothermal power
Mexico is the fourth largest geothermal energy producer worldwide after the USA, the Philippines and Indonesia. This latest project represents Alstom’s return to the fast-growing geothermal market, which is currently present in 70 countries worldwide. From its Morelia manufacturing site, Alstom is preparing geothermal solutions for countries rich in geothermal fields such as the USA, Mexico, Chile, Indonesia, Iceland, Turkey, Philippines and New Zealand.
In addition to the four 25 MW units to the Los Azufres geothermal power plant in Michoacan state won in 2000, Alstom was also awarded another contract in 1998 to supply two 5.5 MW units to the Las Tres Virgenes geothermal power plant in Baja California Sur.
Geothermal power (from the Greek roots geo, meaning earth, and thermos, meaning heat) is power extracted from heat stored in the earth. This geothermal energy originates from the original formation of the planet, from radioactive decay of minerals, and from solar energy absorbed at the surface. It has been used for space heating and bathing since ancient roman times, but is now better known for generating electricity. About 10 GW of geothermal electric capacity is installed around the world as of 2007, generating 0.3% of global electricity demand. An additional 28 GW of direct geothermal heating capacity is installed for district heating, space heating, spas, industrial processes, desalination and agricultural applications.
Geothermal power is cost effective, reliable, and environmentally friendly, but has previously been geographically limited to areas near tectonic plate boundaries. Recent technological advances have dramatically expanded the range and size of viable resources, especially for direct applications such as home heating. Geothermal wells tend to release greenhouse gases trapped deep within the earth, but these emissions are much lower than those of conventional fossil fuels. As a result, this technology has the potential to help mitigate global warming if widely deployed.
Prince Piero Ginori Conti tested the first geothermal generator on 4 July 1904, at the Larderello dry steam field in Italy. The largest group of geothermal power plants in the world is located at The Geysers, a geothermal field in California, United States. As of 2004, five countries (El Salvador, Kenya, the Philippines, Iceland, and Costa Rica) generate more than 15% of their electricity from geothermal sources.
Twenty-four countries generated a total of 56,786 GWh (204 PJ) of electricity from geothermal power in 2005, accounting for 0.3% of worldwide electricity consumption. This output is growing by 3% annually, thanks to a growing number of plants as well as improvements in their capacity factors. Because a geothermal power station does not rely on transient sources of energy, unlike, for example, wind turbines or solar panels, its capacity factor can be quite large; up to 90% has been demonstrated. Their global average was 73% in 2005. The global capacity was 10 GW in 2007.
Geothermal electric power plants have been limited to the edges of tectonic plates until recently.
Geothermal electric plants have until recently been built exclusively on the edges of tectonic plates where high temperature geothermal resources are available near the surface. The development of binary cycle power plants and improvements in drilling and extraction technology has opened the hope that enhanced geothermal systems might be viable over a much greater geographical range. A demonstration project has recently been completed in Landau-Pfalz, Germany, and others are under construction in Soultz-sous-Forêts, France and Cooper Basin, Australia.
Approximately seventy countries made direct use of a total of 270 PJ of geothermal heating in 2004. More than half of this energy was used for space heating, and a third was used for heated pools. The remainder was used for industrial and agricultural applications. The global installed capacity was 28 GW, but capacity factors tend to be low (around 20%) since the heat is mostly needed in the winter. The above figures include 88 PJ of space heating extracted by an estimated million geothermal heat pumps with a total capacity of 15 GW. Global geothermal heat pump capacity is growing by 10% annually.
Direct application of geothermal heat for space heating is far more efficient than electricity generation and has less demanding temperature requirements. It may come from waste heat supplied by co-generation from a geothermal electrical plant or from smaller wells or heat exchangers buried in the shallow ground. As a result it is viable over a much greater geographical range than electricity generation. Where natural hot springs are available, the water may be piped directly into radiators. If the shallow ground is hot but dry, earth tubes or downhole heat exchangers may be used without a heat pump. But even in areas where the shallow ground is too cold to provide comfort directly, it is still warmer than the winter air. Seasonal variations in ground temperature diminish and disappear completely below 10m of depth. That heat can be extracted with a geothermal heat pump more efficiently than it can be generated by conventional furnaces.[5] Geothermal heat pumps can be used essentially anywhere.
There are a wide variety of applications for cheap geothermal heat. The cities of Reykjavík and Akureyri pipe hot water from geothermal plants under roads and pavements to melt snow. District heating applications use networks of piped hot water to heat buildings in whole communities. Geothermal desalination has been demonstrated.
Geothermal fluids drawn from the deep earth may carry a mixture of gases with them, notably carbon dioxide and hydrogen sulfide. When released to the environment, these pollutants contribute to global warming, acid rain, and noxious smells in the vicinity of the plant. Existing geothermal electric plants emit an average of 122 kg of CO2 per MWh of electricity, a small fraction of the emission intensity of conventional fossil fuel plants. Some are equipped with emissions-controlling systems that reduces the exhaust of acids and volatiles.
In addition to dissolved gases, hot water from geothermal sources may contain trace amounts of dangerous elements such as mercury, arsenic, and antimony which, if disposed of into rivers, can render their water unsafe to drink. Geothermal plants can theoretically inject these substances, along with the gases, back into the earth, in a form of carbon capture and storage.
Construction of the power plants can adversely affect land stability in the surrounding region. Subsidence has occured in the Wairakei field in New Zealand and in Staufen im Breisgau, Germany. Enhanced geothermal systems can trigger earthquakes as part of the hydraulic fracturing process. The project in Basel, Switzerland was suspended because more than 10,000 seismic event measuring up to 3.4 on the Richter Scale occurred over the first 6 days of water injection.
Geothermal has minimal requirements for land use and freshwater. Existing geothermal plants use 1-8 acres per megawatt (MW) versus 5-10 acres per MW for nuclear operations and 19 acres per MW for coal power plants. They use 20 litres of freshwater per MWh versus over 1000 litres per MWh for nuclear, coal, or oil.
Geothermal power requires no fuel, and is therefore immune to fluctuations in fuel cost, but capital costs tend to be high. Drilling accounts for most of the costs of electrical plants, and exploration of deep resources entails very high financial risks. At present, the construction of a geothermal electric plant and well costs about 2-5 million € per MW of capacity, while operational costs are 0.04-0.10 € per kWh.
Geothermal power offers a degree of scalability: a large geothermal plant can power entire cities while smaller power plants can supply rural villages or heat individual homes.
Chevron Corporation is the world’s largest producer of geothermal energy. Other companies as Reykjavik Energy Invest build geothermal energy plants around the world.
The heat content of the earth is 1031 Joules. This heat naturally flows up to the surface by conduction at a rate of 40 TW, and is replenished by radioactive decay at a rate of 30 TW. These flow rates are more than twice the rate of human energy consumption from all primary sources, but most of it is too geographically diffuse (0.1 W/m2 on average) to be recoverable. The Earth’s crust effectively acts as a thick insulating blanket which must be pierced by fluid conduits (of magma, water or other) in order to release the heat underneath.
In addition to heat emanating from deep within the Earth, the top 10 m of the ground accumulates solar energy (i.e. warms up) during the summer, and releases that energy (i.e. cools down) during the winter. The seasonal energy stored this way is much smaller in total scale and less dense, but the heat flow rates are much higher, more easily accessible, and evenly distributed around the world. A geothermal heat pump can extract enough heat from shallow ground anywhere in the world to provide wintertime home heating.
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 magma conduits, hot springs, hydrothermal circulation, oil wells, drilled water wells, or a combination of these. This circulation sometimes exists naturally in the most favorable areas where the crust is thin: magma conduits bring the heat close to the surface, and naturally occurring hot springs bridge the last gap to the surface. If no hot spring is available, a well must be drilled into a hot aquifer. Away from tectonic plate boundaries the geothermal gradient is 25-30°C per km of depth in most of the world, and wells would have to be drilled several kilometers 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, it is possible to inject a fluid to stimulate production. Two boreholes are bored into a candidate site, and the deep rock between them is fractured by explosives or high pressure water. Water is pumped down one borehole and steam comes up the other. Liquefied carbon dioxide may also be used. This concept is called hot dry rock geothermal energy in Europe, or enhanced geothermal systems in North America. A much greater resource potential may be available from this approach than from conventional tapping of natural aquifers.
Estimates of the electricity generating potential of geothermal energy vary greatly from 35 to 2000 GW, depending on the scale of financial investments in exploration and technology development. This does not include non-electric heat recovered by co-generation, geothermal heat pumps and other direct use. A 2006 report by MIT, that took into account the use of enhanced geothermal system, estimated that an investment of 1 billion US dollars in research and development over 15 years would permit the development of 100 GW of generating capacity by 2050 in the United States alone. The MIT report estimated that 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 present energy needs for several millennia.
At present, geothermal wells are rarely more than 3km deep. Upper estimates of geothermal resources assume wells as deep as 10 km. Drilling at this depth is now possible in the petroleum industry, although it is an expensive process. For example, Exxon has announced an 11-kilometre (7 mi) hole at the Chayvo field, Sakhalin, and a 12 km well has been reported on the Kola peninsula. Wells drilled to depths greater than 4 kilometres (2 mi) generally incur drilling costs in the tens of millions of dollars.[citation needed] The technological challenges are to drill wide bores at low cost and to break rock over larger volumes.
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 plants 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. These mitigation strategies have already been implemented at some sites. The long-term sustainability of geothermal energy production has been demonstrated at the Lardarello field in Italy since 1913, at the Wairakei field in New Zealand since 1958, and at The Geysers field in California since 1960.
Hot springs have been used for bathing at least since paleolithic times. The oldest known spa is a stone pool on Lisan mountain built in the Qin dynasty in the 3rd century BC, at the same site where the Huaqing Chi palace was later built. In the first century AD, Romans conquered Aquae Sulis and used the hot springs there to feed public baths and underfloor heating. The admission fees for these baths probably represents the first commercial use of geothermal power. The world’s oldest geothermal district heating system in Chaudes-Aigues, France, has been operating since the 14th century. The earliest industrial exploitation began in 1827 with the use of geyser steam to extract boric acid from volcanic mud in Larderello, Italy.
In 1892, America’s first district heating system in Boise, Idaho was powered directly by geothermal energy, and was soon copied in Klamath Falls, Oregon in 1900. A deep geothermal well was used to heat greenhouses in Boise in 1926, and geysers were used to heat greenhouses in Iceland at about the same time. Charlie Lieb developed the first downhole heat exchanger in 1930 to heat his house. Steam and hot water from geysers were used to heat homes in Iceland starting in 1943.
The 20th century saw the rise of electricity, and geothermal power was immediately seen as a possible generating source. Prince Piero Ginori Conti tested the first geothermal power generator on 4 July 1904, at the same Larderello dry steam field where geothermal acid extraction began. It was a small generator that lit four light bulbs. Later, in 1911, the world’s first geothermal power plant was built there. It was the world’s only industrial producer of geothermal electricity until 1958, when New Zealand built a plant of its own.
At this point, the heat pump had long ago been invented by Lord Kelvin in 1852, and the idea of using it to draw heat from the ground had been patented in Switzerland in 1912. But it was not until 1940’s that the idea was successfully implemented. The first commercial geothermal heat pump was designed by J.D. Krocker to heat the Commonwealth Building (Portland, Oregon) in 1946, and Professor Carl Nielsen of Ohio State University built the first residential heat pump two years later. The technology became popular in Sweden as a result of the 1973 oil crisis, and has been growing slowly in worldwide acceptance since then. The development of polybutylene pipe in 1979 greatly augmented its economic viability.[23] As of 2004, there are over a million geothermal heat pumps installed worldwide providing 12 GW of thermal capacity. Each year, about 80,000 units are installed in the USA and 27,000 in Sweden.
In 1960, Pacific Gas and Electric began operation of the first successful geothermal electric power plant in the United States at The Geysers. The original turbine installed lasted for more than 30 years and produced 11 MW net power. The Geysers are currently owned by four companies: the Calpine Corporation, the Northern California Power Agency, Bottlerock Power, and Western GeoPower. They currently produce over 750 MW of power, making them the largest geothermal development in the world.
The binary cycle power plant was first demonstrated in 1967 in Russia and later introduced to the USA in 1981.[2] This technology allows the use of much lower temperature geothermal fields that were previously unrecoverable. In 2006, a binary cycle plant in Chena Hot Springs, Alaska, came on-line, producing electricity from a record low geothermal fluid temperature of 57°C.
Development around the world
Geothermal electricity is generated in 24 countries around the world including the United States, Iceland, Italy, Germany, Turkey, France, The Netherlands[citation needed], Lithuania[citation needed], New Zealand, Mexico, El Salvador, Nicaragua, Costa Rica, Russia, the Philippines, Indonesia, the People’s Republic of China, Japan and Saint Kitts and Nevis. During 2005, contracts were placed for an additional 0.5 GW of electrical capacity in the United States, while there were also plants under construction in 11 other countries. A number of potential sites are being developed or evaluated in South Australia that are several kilometres in depth. When direct use is included, geothermal power is used in over 70 countries.
Installed geothermal electric capacity as of 2007
Country – Capacity (MW)
USA – 2687
Philippines – 1969.7
Indonesia – 992
Mexico – 953
Italy – 810.5
Japan – 535.2
New Zealand – 471.6
Iceland – 421.2
El Salvador – 204.2
Costa Rica – 162.5
Kenya – 128.8
Nicaragua – 87.4
Russia – 79
Papua-New Guinea – 56
Guatemala – 53
Turkey – 38
China – 27.8
Portugal – 23
France – 14.7
Germany – 8.4
Ethiopia – 7.3
Austria – 1.1
Thailand – 0.3
Australia – 0.2
TOTAL – 9731.9
