Geothermal Timeline

	1904	The first dry steam geothermal power plant was built in Laderello in Tuscany, Italy. The Larderello plant today provides power to about one million households.

	1960	The first commercial-scale development tools were placed in California at The Geysers, a 10-megawatt unit owned by Pacific Gas & Electric.

	1970	Re-injection of spent geothermal water back into the production reservior was introduced as a way to dispose of waste water and extend reservoir life.

	1972	Deep well drilling technology improvements led to deeper reservoir drilling and access to more resources.

	1974	Scientists began to develop the first hot dry rock (HDR) reservoir at Fenton Hill, New Mexico. An HDR power facility was tested at the site in 1978 and started to generate electricity two years later.

	1978	U.S. Department of Energy (DOE) funding for geothermal research and development was increased substantially. Public Utility Regulatory Policies Act (PURPA) was enacted to promote greater use of renewable energy, cogeneration and small power projects.

	1980	The first commercial-scale binary plant in the United States began operation in Southern California’s Imperial Valley.

	1980s	California’s Standard Offer Contract system for PURPA qualifying facilities provided renewable electric energy systems a relatively firm and stable market for output, allowing the financing of capital-intensive technologies like geothermal energy facilities.

	1982	Geothermal (hydrothermal) electric generating capacity, reached a new high of 1,000 megawatts.

	1984	Utah’s first commercial geothermal power plant began operating at Roosevelt Hot Springs with a 20 MW capacity. Nevada’s first geothermal binary power production plant began operating at Wabuska Hot Springs.

	1989	DOE and the Electric Power Research Institute operated a 1-megawatt geopressured power demonstration plant in Texas,extracting methane and heat from brine liquids.

	1990	DOE funding for geothermal energy research and development declined throughout the 1980s and reached a low of $15 million.

	1991	The world’s first magma exploratory well was drilled in the Sierra Nevada Mountains to a depth of 7,588 feet. It did not encounter magma at that depth inside the caldera.

	1992	The Puna field of Hawaii began electrical generation at a 25 megawatt geothermal plant.

	1994	California Energy became the world’s largest geothermal company through its acquisition of Magma Power.

	1995	Worldwide geothermal capacity reached 6,000 megawatts. At Empire Nevada, a food-dehydration facility processed 15 million pounds of dried onions and garlic per year using geothermal resources. A DOE low-temperature resource assessment of 10 western states identified nearly 9000 thermal wells and springs and 271 communities with a geothermal resource greater than 50ºC.

	1999	California's geothermal power plants provided 54.9 percent of the state’s electricity.

	2000	The Department of Energy and Industry worked together on the Geothermal Resource Exploration and Definition Program. It was a cooperative effort to find, evaluate, and define additional geothermal resources throughout the western United States.

	2004	Geothermal energy costs dropped from $.10 - .16 per kilowatt hour to $.5 - .8 per kilowatt hour.

	2006	U.S. geothermal industry became a $1.5 billion per year business that involved electricity generation and thermal energy in direct use such as indoor heating, greenhouses, food drying, aquaculture, etc. Alaska installed a 200 kW power plant that used low temperature (74º C) geothermal water along with (4º C) cooling water.

	2008	Idaho’s first commercial geothermal power plant began operating.

Last Revised: July 2008.
Sources: U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, A History of Geothermal in the United States, January 2008.
California Energy Commission, Overview of Geothermal Energy in California, January 2008.
California Energy Commission, California Geothermal Resources , January 2008.
California Energy Commission, Geothermal Technologies Program, January 2008.
U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Geothermal Research , January 2008.
Oregon Institute of Technology, JHC Bulletin, Development and Utilization of Geothermal Resources, June 2007.