USGS Newsroom

Geothermal power production could significantly add to the electric power generating capacity in the United States. 

The U.S. Geological Survey assessment released today is the first national geothermal resource estimate in more than 30 years.

The results of this assessment 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 (high temperature, low permeability) Enhanced Geothermal Systems (EGS) resources. 

The results of this assessment indicate that full development of the conventional, identified systems alone could expand geothermal power production by approximately 6,500 MWe, or about 260% of the currently installed geothermal total of more than 2500 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," said 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."

Results of this USGS assessment indicate that the power generation potential from identified geothermal systems range from 3,675 MWe (95% probability) to 16,457 MWe (5% probability); the power generation potential from undiscovered geothermal systems range from 7,917 MWe (95% probability) to 73,286 MWe (5% probability); and the power generation potential from Enhanced Geothermal Systems range from 345,100 MWe (95% probability) to 727,900 MWe (5% probability).

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% of domestic nonhydroelectric renewable electric power generation (a little over 4,055,400 total Gigawatt-hours of electricity were produced in the United States in 2005). 

The USGS assessment evaluated 241 identified moderate-temperature (90 to 150^oC; 194 to 302^oF) and high-temperature (greater than 150^oC) 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 was also determined for several low-temperature (less than 90^oC) systems in Alaska for which 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.

This assessment benefited from cooperation with the Department of Energy, Bureau of Land Management, the University of Nevada - Reno, the University of Utah, Idaho National Laboratory, Lawrence Berkeley National Laboratory, state and local agencies, and the geothermal industry.

To learn more about USGS National Geothermal Resource efforts and to see results of the assessment, please visit the Energy Resources Web site.