9. Geothermal

C. Infrastructure

Manufacturing Industry

The geothermal manufacturing industry makes use of technologies that had their start in the oil and gas drilling industry and in the traditional electrical power plant industry. The geothermal industry developers have taken these early technologies and improved them to meet the needs of geothermal production.

Many U.S. geothermal developers were involved in technology advances to meet the challenges of new sites and the extent of their recoverable energy. The challenges also include lower temperature liquid resources and dealing with highly corrosive and scale prone liquid brines. Advances have resulted in lower capital and operating costs, reduced leadtimes for plant construction, and additional geographic regions with available resources.


There are approximately 14 active geothermal developers in the United States. Historically, most nonutility geothermal resource developers viewed their business as exploring, developing, and selling steam to utilities. After the passage of PURPA, however, developers began to build their own generating plants, selling the generated electricity to utilities under PURPA rules. Several developers began to use proprietary conversion technologies to exploit hot water geothermal reservoirs with very corrosive liquid brines.

Many of the original, large, diversified players, particularly oil or minerals companies, have now left the geothermal business. Since 1986, a class of medium-sized firms has emerged, outgrowing the small entrepreneurial classification through substantial growth of individual companies, mergers, and acquisitions.

Electric Utilities

Most direct utility involvement in geothermal electricity generation in the United States is at The Geysers resource area. Pacific Gas & Electric Company is the utility leader in geothermal development, with more than 1,200 megawatts of capacity. Other utilities owning geothermal capacity in the United States include the Northern California Power Agency, the Sacramento Municipal Utility District, and the Utah Municipal Power Authority. Other utilities purchasing electricity or steam for power production from geothermal resources include Southern California Edison Company, Sierra Pacific Power Company, and Hawaii Electric Light Company. Several utilities are active in geothermal development through for-profit subsidiaries in the independent power marketplace.

Access to utility transmission systems has been an important asset to geothermal resource development. Where access has not been available, several projects have installed their own plant transmission outlet. In the future, electric utilities are expected to prearrange power purchases from planned geothermal projects. For example, the Bonneville Power Administration has offered power contracts for geothermal development at two sites in Oregon, and other developers expect to sell output to the Los Angeles Department of Water and Power.

Return to Table of Contents
* * *