History

People have used geothermal resources in many ways, including healing and physical therapy, cooking, space heating, and other applications. One of the first known human uses of geothermal resources was more than 10,000 years ago with the settlement of Paleo-Indians at hot springs.⁹ Geothermal resources have since been developed for many applications such as production of electricity and geothermal heat pumps. Prince Piero Ginori Conti invented the first geothermal power plant in 1904, at the Larderello dry steam field in Italy¹⁰. The first geothermal power plants in the United States were operated in 1960 at The Geysers in Sonoma County, California. Table 1 (below) shows the timeline of the recent history of geothermal energy in the United States.

Year	Event
1960	The first large-scale geothermal plant was opened and operated at The Geysers in California, with a capacity of 11 MW.
1970	The Geothermal Resources Council is formed to encourage the development of geothermal resources worldwide. The Geothermal Steam Act is enacted, providing the Secretary of the Interior with the authority to lease public lands and other federal lands for geothermal exploration and development in an environmentally sound manner. Reinjection of geothermal fluids of spent geothermal fluids back into the production zone began as a means to dispose of wastewater and maintain reservoir life.
1972	The Geothermal Energy Association is formed. The association comprises U.S. companies that develop geothermal resources worldwide for electrical power generation and direct-heat uses. Deep-well drilling technology improvements led to deeper reservoir drilling and access to more resources.
1974	The U.S. government enacts the Geothermal Energy Research, Development and Demonstration (RD&D) Act, instituting the Geothermal Loan Guaranty Program, which provides investment security to public and private sectors using and developing technologies to exploit geothermal resources.
1975	The Energy Research and Development Administration (ERDA) is formed, with the goal of focusing the federal government’s energy research. The Division of Geothermal Energy takes over the RD&D program begun in 1974.
1977	The U.S. Department of Energy (DOE) is formed. Hot dry rock geothermal power demonstrated with financial assistance from DOE. Scientists develop the first hot dry rock reservoir at Fenton Hill, New Mexico.
1978	The Public Utility Regulatory Policies Act (PURPA) is enacted. PURPA mandated the purchase of electricity from qualifying facilities (QFs: small power producers using renewable energy sources and cogenerators) meeting certain technical standards regarding energy source and efficiency. PURPA also exempted QFs from both State and Federal regulation under the Federal Power Act and the Public Utility Holding Company Act.
1981	With support from DOE, Ormat successfully demonstrates binary technology in the Imperial Valley of California. The project established the technical feasibility of larger-scale commercial binary power plants. The project is so successful that Ormat repays the loan within a year.
1982	Economic electrical generation begins at California’s Salton Sea geothermal field using crystallizer–clarifier technology. The technology resulted from a government/industry effort to manage the high-salinity brines at the site. Geothermal (hydrothermal) electric generating capacity, primarily utility-owned, reached a new high level of 1,000 MW.
1989	The world’s first hybrid (organic Rankine/gas engine) geopressure-geothermal power plant begins operation at Pleasant Bayou, Louisiana, using both the heat and the methane of a geopressured resource.
1994	DOE creates two industry/government collaborative efforts to promote the use of geothermal energy to reduce greenhouse gas emissions. One effort is directed toward the accelerated development of geothermal resources for electric power generation; the other is aimed toward the accelerated use of geothermal heat pumps.
1995	A DOE low-temperature resource assessment of 10 western states identified nearly 9,000 thermal wells and springs and 271 communities co-located with a geothermal resource greater than 50°C. Worldwide geothermal capacity reaches 6,000 MW.
2000	DOE initiates its GeoPowering the West program to encourage development of geothermal resources in the western United States. An initial group of 21 partnerships with industry is funded to develop new technologies.

Endnotes
9. Geothermal Energy Program: A History of Geothermal in the United States http://www.eren.doe.gov/geothermal/geohistory.html; accessed Sep 30, 2002
10. Geothermal Education Office. http://www.geothermal.marin.org/GEOpresentation/sld050.htm; accessed Sep 30, 2002.