Along with its famous, sprawling vineyards, Sonoma County holds another notable natural resource, less known to tourists but a point of mystery and fascination to locals: The Geysers. The Geysers are tucked away in the folds of the Mayacamas Mountains, ranging along the Sonoma and Lake county borders. Within the 45 square miles of steam fields are 333 steam wells feeding 15 geothermal power plants with 725 megawatts of generation capacity. Over the past decade, this extensive facility has generated an average of 6 million megawatts per year and held by Calpine*.
Unlike the younger and more trendy resource of solar energy, geothermal power has had a long history of use. Even hundreds of years ago, The Geysers supported six native American tribes who used the hot water to cook and for healing purposes. By 1955, the first commercial steam well was drilled and the number of wells continue to increase. The most recent steam well to date was drilled on January 13, 2014.
The Geysers system of energy production is reliant on the cycle of water found in fractures in the earths crust, which are heated and emerge as steam. The wells collect and direct this steam to plants where the steam turns turbines to generate power. By 1987, energy production from The Geysers had peaked and rapidly declined over the next eight years with the loss of water pressure. To continue the cycle of steam power, water had to be injected back into the rocks to replace what was exiting as steam. This resulted in an innovative collaboration with Santa Rosa, which was facing a challenge of where to dispose of its waste water in a safe way. This wastewater is injected back into the ground, correcting the water pressure and steam production so that the geothermal plants can continue to produce clean and reliable energy.
This water injection process highlights one of the stark advantages geothermal energy has over it’s popular green counter parts: wind and solar. Geothermal is not limited by weather. Plants run 24-7, regardless of the time of day, cloud cover, or windiness. During the winter, when there is notably less sunlight for solar power, the increased rain that comes with the season allows for more water to be injected into the wells, generating even more power.
Because The Geysers are located on private land and the location is a 24-hour operation with important safety requirements, the general public is not permitted to explore the facilities on their own. Many locals who have been curious about the operation, aren’t even aware of the periodic guided tours that will allow interested members of the public to visit the wells and power plants.
We visited The Geysers on the most recent tour last Friday, February 13. While this tour started in Cloverdale, other tours have started from locations such as the Calpine Geothermal Visitor’s Center in Middletown, CA, and other locations in Middletown, Geyserville, and Santa Rosa. It is a very long ride on the bus from Cloverdale to The Geysers, and we have since been informed that the tour starting from the Calpine Geothermal Visitors Center is a shorter ride. In hindsight, we would probably try that tour if we did this again.
To learn more about The Geysers and find out about the next upcoming tour, visit: www.calpine.com