Power Developers Tapping California's Geothermal Resources for Power Generation Expansion

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Researched by Industrialinfo.com (Industrial Information Resources, Incorporated; Houston, Texas). Geologic forces deep beneath California have provided power developers a rich region of green energy supply. Due to its abundant geothermal resources, California leads the nation in the development of geothermal power and currently operates 27 geothermal plants producing 2,651 megawatts (MW). At least five grassroot plants and several expansions of existing plants are being developed, which could see geothermal power production increase by over 21 percent in the state during the next several years.

For a listing of California's geothermal power plants click on the image at right.

For example, CalEnergy Generation (Ridgecrest California), a subsidiary of MidAmerican Holdings (Des Moines, Iowa), a division of Berkshire Hathaway Incorporated (NYSE: BRK) (Omaha, Nebraska), has received a recommendation for approval on its 190 MW Salton Sea VI project (PEC 06003507) and is now waiting for final California Energy Commission's final approval to begin construction. That approval is expected in December. Salton Sea VI Geothermal Plant has been designed to be the largest single geothermal unit ever built it is being studied to use a flash steam power system (water between 300F & 700F) and if approved could be operational in 2006.

Other companies are reevaluating their geothermal properties, such as Constellation Energy (NYSE: CEG.N) (Baltimore, Maryland) who is conducting studies to determine if selling their 50 percent interest in the 40-megawatt (MW) Mammoth Lakes Geothermal Power Plant (PLANT 1013482) would be more profitable than retaining ownership. Mammoth Pacific Limited Partnership is a 50/50 joint venture formed between Constellation and Covanta Energy (NYSE: COV) (Fairfield, New Jersey) and is operated by a division of Covanta. The Mammoth Lake Geothermal Power Plant is located on 10 acres and consists of three power islands with a total of eight turbines, it has six injection wells each reaching depths of 2,000 feet or deeper and utilizes geothermal fluid that is between 300F & 350F.

There's a reason why California has more geothermal energy than other state. Geothermal energy is produced from geothermal heat, which originates in the earth's interior, where temperatures reach over 9,000 degrees Fahrenheit. In California's case, it is in close proximity to a plate tectonic subduction zone, which is the main cause of the geothermal activity in the state. A plate tectonic subduction zone is an area where one part of the earth's crust is being pushed beneath another. When the crust reaches a certain depth it begins to melt into magma. Magma being lighter than surrounding rock moves up toward the earth's surface. The magma heats the rock and water as it rises. Some of the heated/geothermal water travels to the surface where it is manifest as hot springs or geysers. This tectonic activity is also the cause of California's earthquakes.

Power developers tap geothermal sources by drilling wells. The thermal heat is used to drive turbines at a power plant on the surface.