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California Geothermal Energy Statistics & Data

photo of Geysers Geothermal Plants

Because of its location on the Pacific's "ring of fire" and because of tectonic plate conjunctions, California contains the largest amount of geothermal generating capacity in the United States.

In 2007, geothermal energy in our state produced 13,000 gigawatt-hours (GWh) of electricity. Combined with another 440 GWh of imported geothermal electricity, then geothermal energy produced 4.5 percent of the state's total system power. A total of 42 operating geothermal power plants with an installed capacity of 1,727 megawatts are in California, about two-thirds of the total United States' geothermal generation.

The largest concentration of geothermal plants is located north of San Francisco in the Geysers Geothermal Resource Area in Napa and Sonoma Counties (shown in photo on the right). This location has been producing electricity since the 1960s. It uses dry steam; one of only two places in the world for this resource (the other being in Larderello, Italy).

 

Geothermal Electricity Production
(In Gigawatt-Hours; Includes Imports)


1983 1984 1985 1986 1987 1988 1989
Geothermal 7,020 9,272 10,957 13,094 14,083 14,194 15,247
Total Generation 199,609 211,900 210,172 211,028 220,371 232,926 238,567
 
1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
Geothermal 16,038 15,566 16,491 15,770 15,573 14,267 13,539 11,950 12,554 13,251
Total Generation 252,355 242,343 245,535 242,026 256,719 256,367 253,621 255,080 276,412 275,803
 
2000 2001 2002 2003 2004 2005 2006 2007
Geothermal 13,456 13,619 13,867 13,771 14,000 14,380 13,226 13,439
Total Generation 280,496 265,059 272,509 276,969 289,359 287,977 295,268 302,072