By the year 2020 the world?s presently identified oil reserves will be depleted. The United States has developed a National Energy Plan to conserve remaining oil supplies, reduce dependency on foreign oil supplies, and develop non-conventional energy sources, including geothermal. Geothermal energy could account for 4% of the nation's electrical energy production by 1990. Geothermal resources can be divided into the following types a) vapor dominated, b) liquid dominated, c) geopressure, d) hot dry rock, and e) Magma. Approximately 1.4 million ha of land have been designated by the U.S. Geological Survey as Known Geothermal Resource Areas (KGRA). California and Nevada account for 60% of the KGRA lands. 502 mw of electrical energy is now being produced at the Geysers KGRA. To operate one 110 mw geothermal power plant in The Geysers requires between 16- 35 steam wells producing a total of 900,000 kgs of steam per hour for the 30 year life of the plant. The 110 mw power plant and attendant steam wells encompasses about 280 ha of land. Direct utilization of geothermal energy (nonelectric) is in its infancy in the United States. Geothermal resources with temperature less than 150 C can be used for greenhousing, fruit and vegetable dehydration space heating and aquaculture. The statement that geothermal energy production is nonpolluting is not entirely correct. Geothermal energy development has inherent restrictions and environmental problems, including site specificity; heat loss during steam/fluid transmission; extensive road, steam and electric transmission line networks; moderate land disturbance, up to 20% of the surface area; and potential air and water quality tradeoffs. Mitigation measures for wildlife habitat losses are generally restricted to revegetation of some denuded areas. In order to better assess the impacts to fish and wildlife resources resulting from geothermal development, baseline data are needed prior to exploration and development activities.
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