Could idle wells at The Geysers be a clean power solution?

Jeff Quackenbush, NORTH BAY BUSINESS JOURNAL

A new generation of geothermal technology has proven itself in field testing in Northern California, where a state-funded demonstration at The Geysers suggests old and underperforming wells could become a faster, lower-impact path to more clean electricity.

A California Energy Commission report published in April found that GreenFire Energy’s advanced geothermal system, tested in a well at the Socrates plant, also known as Unit 18, could help unlock more than 200 megawatts (200,000 kilowatts) of potential additional electricity production in idle geothermal wells across California, enough to power over 200,000 homes. The test used a closed-loop, pipe-in-pipe heat exchanger rather than the conventional method of pulling steam or hot water from the reservoir.

The demonstration matters because California has struggled to expand geothermal power even as the state increasingly needs clean electricity that runs around the clock. Solar and wind have grown rapidly, but geothermal can generate during winter storms, at night and during multi-day periods when batteries are depleted.

“We’re working to build the renewable energy resources that will keep the lights on through the winter when solar and wind are not producing and batteries are empty,” said Geof Syphers, CEO of Sonoma Clean Power. “Geothermal is one of those key resources.”