| Geothermal power is generated by mining
| |
| | Geothermal power is very cost-effective
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| the earth's heat. In areas with high
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| | in the Rift area of Africa. Kenya's
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| temperature ground water at shallow
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| | KenGen has built two plants, Olkaria I
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| depths, wells are drilled into natural
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| | (45 MW) and Olkaria II (65 MW), with a
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| fractures in basement rock or into
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| | third private plant Olkaria III (48 MW)
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| permeable sedimentary rocks. Hot water or
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| | run by Israeli geothermal specialist
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| steam flows up through the wells either
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| | Ormat. Plans are to increase production
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| by pumping or through boiling (flashing)
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| | capacity by another 576 MW by 2017,
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| flow. Experiments are in progress to
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| | covering 25% of Kenya's electricity
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| determine if a fourth method, deep wells
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| | needs, and correspondingly reducing
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| into "hot dry rocks", can be economically
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| | dependency on imported oil.
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| used to heat water pumped down from the
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| | Geothermal power is generated in over 20
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| surface. A hot dry rock project in the
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| | countries around the world including
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| United Kingdom was abandoned after it was
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| | Iceland (producing 17% of its electricity
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| pronounced economically unviable in 1989.
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| | from geothermal sources), the United
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| HDR programs are currently being
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| | States, Italy, France, New Zealand,
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| developed in Australia, France,
| |
| | Mexico, Nicaragua, Costa Rica, Russia,
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| Switzerland and Germany. Magma (molten
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| | the Philippines (production output of
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| rock) resources offer extremely
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| | 1931MW (2nd to US, 27% of electricity),
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| high-temperature geothermal
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| | Indonesia, the People's Republic of China
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| opportunities, but existing technology
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| | and Japan. Canada's government (which
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| does not allow recovery of heat from
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| | officially notes some 30,000 earth-heat
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| these resources.
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| | installations for providing space heating
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| Electrical generation
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| | to Canadian residential and commercial
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| Geothermal-generated electricity was
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| | buildings) reports a test
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| first produced at Larderello, Italy, in
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| | geothermal-electrical site in the Meager
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| 1904. Since then, the use of geothermal
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| | Mountain–Pebble Creek area of British
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| energy for electricity has grown
| |
| | Columbia, where a 100 MW facility could
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| worldwide to about 8,000 megawatts.
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| | be developed.
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| Three types of power plants are used to
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| | Desalination
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| generate power from geothermal energy:
| |
| | Douglas Firestone began working with
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| dry steam, flash, and binary. Dry steam
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| | evaporation/condensation air loop
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| plants take steam out of fractures in the
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| | desalination about 1998 and proved that
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| ground and use it to directly drive a
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| | geothermal waters could be used as
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| turbine that spins a generator. Flash
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| | process water to produce potable water in
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| plants take hot water, usually at
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| | 2001. In 2003 Professor Ronald A.
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| temperatures over 200°C, out of the
| |
| | Newcomb, now at San Diego State
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| ground, and allows it to boil as it rises
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| | University Center for Advanced Water
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| to the surface then separates the steam
| |
| | Technologies began to work with Firestone
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| phase in steam/water separators and then
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| | to enhance the process of using
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| runs the steam through a turbine. In
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| | geothermal energy for the purpose of
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| binary plants, the hot water flows
| |
| | desalination. Geothermal Energy is a
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| through heat exchangers, boiling an
| |
| | primary energy source.
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| organic fluid that spins the turbine. The
| |
| | In 2005 some testing was done in the
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| condensed steam and remaining geothermal
| |
| | fifth prototype of a device called the
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| fluid from all three types of plants are
| |
| | “Delta T” a closed air loop,
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| injected back into the hot rock to pick
| |
| | atmospheric pressure, evaporation
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| up more heat. This is why geothermal
| |
| | condensation loop geothermally powered
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| energy is viewed as sustainable. The heat
| |
| | desalination device. The device used
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| of the earth is so vast that there is no
| |
| | filtered sea water from Scripps Institute
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| way to remove more than a small fraction
| |
| | of Oceanography and reduced the salt
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| even if most of the world's energy needs
| |
| | concentration from 35,000 ppm to 51 ppm w
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| came from geothermal sources.
| |
| | w.
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| The largest dry steam field in the world
| |
| | Water injection
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| is The Geysers, about 90 miles (145 km)
| |
| | In some locations, the natural supply of
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| north of San Francisco. The Geysers began
| |
| | water producing steam from the hot
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| in 1960 which has 1360 MW of installed
| |
| | underground magma deposits has been
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| capacity and produces about 1000 MW net.
| |
| | exhausted and processed waste water is
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| Calpine Corporation now owns 19 of the 21
| |
| | injected to replenish the supply. Most
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| plants in The Geysers and is currently
| |
| | geothermal fields have more fluid
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| the United States' largest producer of
| |
| | recharge than heat, so re-injection can
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| renewable geothermal energy. The other
| |
| | cool the resource, unless it is carefully
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| two plants are owned jointly by the
| |
| | managed. In at least one location, this
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| Northern California Power Agency and
| |
| | has resulted in small but frequent
|
| Santa Clara Electric. Since the
| |
| | earthquakes (see external link below).
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| activities of one geothermal plant
| |
| | This has led to disputes about whether
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| affects those nearby, the consolidation
| |
| | the plant owners are liable for the
|
| plant ownership at The Geysers has been
| |
| | damage the earthquakes cause.
|
| beneficial because the plants operate
| |
| | Cost
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| cooperatively instead of in their own
| |
| | Geothermal power is more competitive in
|
| short-term interest. The Geysers is now
| |
| | countries that have limited hydrocarbon
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| recharged by injecting treated sewage
| |
| | resources, but have plentiful geothermal
|
| effluent from the City of Santa Rosa and
| |
| | sites, such as Iceland, New Zealand, and
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| the Lake County sewage treatment plant.
| |
| | Italy. During the period of low power
|
| This sewage effluent used to be dumped
| |
| | prices in the 1980s up to the recent rise
|
| into rivers and streams and is now piped
| |
| | in oil and gas prices, few geothermal
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| to the geothermal field where it
| |
| | resource areas in the United States were
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| replenishes the steam produced for power
| |
| | capable of generating electricity at a
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| generation.
| |
| | cost competitive with other energy
|
| Another major geothermal area is located
| |
| | sources. However, recent rises in power
|
| in south central California, on the
| |
| | prices make geothermal more cost
|
| southeast side of the Salton Sea, near
| |
| | competitive.
|
| the cities of Niland and Calipatria,
| |
| | Not all areas of the world have a usable
|
| California. As of 2001, there were 15
| |
| | geothermal resource, though many do.
|
| geothermal plants producing electricity
| |
| | Also, some geothermal areas do not have a
|
| in the area. CalEnergy owns about half of
| |
| | high enough temperature to produce steam.
|
| them and the rest are owned by various
| |
| | In those areas, geothermal power can be
|
| companies. Combined the plants produce
| |
| | generated using a process called binary
|
| about 570 megawatts.
| |
| | cycle technology, though the efficiency
|
| The Basin and Range geologic province in
| |
| | is lower. Other areas do not have the
|
| Nevada, southeastern Oregon, southwestern
| |
| | water to produce steam, which is
|
| Idaho, Arizona and western Utah is now an
| |
| | necessary for current plant designs.
|
| area of rapid geothermal development.
| |
| | Geothermal areas without steam are called
|
| Several small power plants were built
| |
| | hot dry rock areas and methods for
|
| during the late 1980s during times of
| |
| | exploiting them are being researched.
|
| high power prices. Rising energy costs
| |
| | Also, instead of producing electricity,
|
| have spurred new development. Plants in
| |
| | lower temperature areas can provide space
|
| Nevada at Steamboat near Reno, Brady
| |
| | and process heating. As of 1998, the
|
| Desert Peak, Dixie Valley, Soda Lake,
| |
| | United States has 18 district heating
|
| Stillwater and Beowawe now produce about
| |
| | systems, 28 fish farms, 12 industrial
|
| 235 MW. New projects are under
| |
| | plants, 218 spas and 38 greenhouses that
|
| development across the state.
| |
| | use geothermal heat.
|
