This paper analyzes the fifty-year history of commercial power generation at The Geysers geothermal field in California as six distinct and consecutive periods (1960-1969, 1969-1979, 1979-1986, 1986-1995, 1995-1998, 1998-2004 and 2004-2010) reflecting the intricate interrelationship between the prevailing socio-economic forces, field development and management practices, and consequent reservoir response. It is shown that this field has proven to be by far the largest source of commercial geothermal power tapped to date in the world, and its history presents a singularly pioneering case of ingenious field management in the face of unpredictable socio-economic forces and challenging reservoir behavior. The most important innovation in this regard has been the augmentation of injection into the reservoir by piping in treated municipal effluents from long distances outside the field.

It is shown that (a) this field by now has produced electricity equivalent to a 1,033 MW plant producing at 90% capacity factor over a typical project life of 30 years; and (b) innovations in field management have led to a 33% higher generation level today than forecast two decades ago. This paper also attempts to forecast the future of this field. We believe the present generation capacity of about 850 MW will have declined to about 700 MW over the next two decades, taking into account the planned addition of at least 100 MW new capacity in the near future. A century since its exploitation began, this field would still be exploited by continued injection into the relatively pressure depleted reservoir, or possibly topping the yet-unexploited ultra-high temperature zones known to exist below the exploited system. Finally, we point out the lessons learned by the geothermal industry from the history of this unique field.

Press the Back button in your browser, or search again.

Copyright 2011, Stanford Geothermal Program: Readers who download papers from this site should honor the copyright of the original authors and may not copy or distribute the work further without the permission of the original publisher.