Geothermal energy is the use of steam and hot water generated by heat from the earth to perform work. Some geothermal power plants use steam or hot water from a natural underground reservoir to power generators for electricity generation.. Others use hot water to provide direct heat for residential and other buildings, and for other applications.
Geothermal energy accounts for 17 percent of renewable electricity generation, and 0.3 percent of total U.S. electricity supply. Almost 50% of the nation's production of geothermal energy is on federal land. Much of the geothermal activity on federal lands takes place in California and Nevada. Other states with geothermal activity include Utah, New Mexico and Oregon. The Bureau of Land Management administers 29 power plants, using federal resources in California, Nevada and Utah. The power plants have a total capacity of 1250 megawatts and supply the needs of 1.2 million homes. In California alone, geothermal energy displaces the need for over 9 million barrels of oil per year. Both federal and non-federal power plants in California produce about 40% of the world's geothermal-generated electricity. In terms of heat (BTU) energy, production from bureau leases in California constitutes about 87% of the nation's federal geothermal production, followed by Nevada (9%), Utah (3%), and New Mexico (<1%).
For a map showing the geothermal potential of the U.S., see page 6-3 of the National Energy Policy report, May 2001.