This is an excerpt from EERE Network News, a weekly electronic newsletter.
New Water Pipeline Feeds World's Largest Geothermal Facility
Calpine Corporation announced on December 5th that a 40-mile pipeline is now supplying recycled water to The Geysers, the world's largest geothermal facility. The Santa Rosa Geysers Recharge Project is meant to extend the commercial life of The Geysers geothermal resource, located in northern California. The Geysers is a rare type of geothermal field in which the energy is carried by dry steam. Although the geothermal heat supplying the resource remains essentially constant, the constant release of steam from the underground resource threatens to deplete the subterranean supply of water, which is essential to transport the geothermal energy to the surface. To remedy that situation, the new pipeline is carrying 11 million gallons of recycled water per day from the City of Santa Rosa's municipal water system to The Geysers, where it is being injected into the underground reservoir of steam. See the Calpine press release and the project description from the City of Santa Rosa.
Calpine owns 19 of the 21 geothermal facilities at The Geysers, which covers a 30-square-mile area that straddles the border of Lake and Sonoma counties. According to the Geothermal Energy Association (GEA), the power plants at The Geysers have a total rated capacity of 1,650 megawatts, although the plants are currently achieving an average annual net capacity of only 862 megawatts. See the GEA Web site.
While the new Geysers pipeline aims to maintain an existing geothermal energy source, researchers at DOE's Idaho National Engineering and Environmental Laboratory (INEEL) are working to help geothermal developers find new resources to tap. The researchers have generated a new regional geothermal resource map and individual resource maps for 13 Western states (including Alaska and Hawaii), available on the INEEL Web site.