A new study suggests that geothermal power production could significantly add to the electric power-generating capacity in the United States. The recent U.S. Geological Survey (USGS) assessment finds that geothermal energy has the potential to generate more than 500 gigawatts of electricity for the nation.

The results of this assessment, the first national geothermal resource estimate in more than 30 years, show that the United States has an estimated 9,057 Megawatts-electric (MWe) of power generation potential from domestic, conventional, identified geothermal systems; 30,033 MWe of power generation potential from conventional, undiscovered geothermal resources; and 517,800 MWe of power generation potential from unconventional enhanced geothermal systems (EGS) resources. 

The results indicate that full development of the conventional, identified systems alone could expand geothermal power production by approximately 6,500 MWe, or about 260 percent of the currently installed geothermal total of more than 2,500 MWe. The resource estimate for unconventional EGS is more than an order of magnitude larger than the combined estimates for both identified and undiscovered conventional geothermal resources, and, if successfully developed, could provide an installed geothermal electric power-generation capacity equivalent to about half of the currently installed electric power-generating capacity in the United States.

"The results of this assessment point to a greater potential for geothermal power production than previous assessments," says Dirk Kempthorne, U.S. Secretary of the Interior. "Geothermal energy is not only a renewable resource, but could significantly contribute to our domestic energy resource base."

Geothermal energy is an extremely important but underutilized domestic, renewable energy resource. The nearly 15,000 gigawatt-hours of geothermal power generated in 2005 constituted 25 percent of domestic non-hydroelectric renewable electric power generation (a little more than 4,055,400 total gigawatt-hours of electricity were produced in the United States in 2005). 

The USGS assessment evaluated 241 identified moderate-temperature (194 degree F to 302 degree F) and high-temperature (greater than 302 degree F) geothermal systems located on private and public lands. Geothermal systems located on public lands closed to development, such as national parks, were not included in this assessment. Electric-power generation potential also was determined for several low-temperature (less than 194 degree F) systems in Alaska, where local conditions make electric power generation feasible. The assessment also included a provisional estimate of the power-generation potential from the application of unconventional EGS technology.

To learn more about USGS National Geothermal Resource efforts, and to see results of the assessment, please visit http://energy.usgs.gov.