LAKE COUNTY (KCBS)— It’s the single largest power-generating operation of its kind on the planet and is an important part of California’s green energy portfolio. But hardly anyone in the Bay Area knows what it is or where it is.
The Geysers geothermal fields are about 75 miles north of San Francisco. A drive up a narrow road will lead you to the Mayacamas Mountains with Santa Rosa to the west and Clear Lake to the east. When you arrive, it’s 45 square miles of land, populated by 15 large geothermal power plants.
In the 1950s, America’s thirst for electricity was on the rise, but by the ‘60s, a booming California population created a power drought. PG&E then decided to harvest steam.
“We’re on the turbine deck and what we have are two turbines— the A and the B,” explains Jim Kluesener, vice president of Calpine, the company that operates the geysers.
The geysers themselves date back a million years when hot volcanic magma was trapped many miles underneath many miles below the Earth’s crust. Steam is created when the hot rock heats up a water aquifer above it.
“We’re very fortunate. We’re one of two places in the world that actually has dry steam. So it carries a lot more energy,” Kluesener said.
They contain enough power to light up 700,000 homes with green energy.
The geysers became the wonder of the world and big news during the 1970s energy crisis when President Jimmy Carter talked about intolerable dependence on foreign oil.
By the mid-1990s, the water nearly tapped out and the geysers began running out of steam. The solution was something residents and Lake County and Santa Rosa were more than happy to get rid of.
“We are replenishing our steam reservoir using treated wastewater from local communities,” he said.
But the geysers aren’t without their faults.
Meriel Medrano’s garden in Anderson Springs isn’t far from the geothermal fields. It’s normally peaceful except when the Earth starts to shake.
“It gets pretty bad,” she says. The quakes began when Calpine started pumping large amounts of treated wastewater from Santa Rosa and Lake County into its wells.
“The community itself has had chimneys fall down, broken windows,” says Madrano.
Jeff Gospe with the Anderson Springs Community Alliance says it feels like a truck hitting your house.
“The fundamental problem with the geysers is they over-depleted the resource,” Gospe said.
When Calpine began pumping that treated wastewater into the steam fields, earthquakes in the 2, 3 and 4 magnitude range began rattling homes and nerves.
“We’re hoping that though time we’d have a better understanding of how these can be mitigated,” said Kluesener.
Calpine has spent millions studying the quakes. The Lawrence Berkeley National Laboratory has installed dozens of ground motion detectors and a top geophysicist is creating three-dimensional computer images of the Earth above and below the geyser fields.
“We’re also very closely monitoring when we do have seismic events and noting how many gallons of water we’re adding close to where the event is,” said Kluesener.
Residents like Medrano say they have felt fewer quakes.
“It’s been a little better lately,” she said.
She and other residents just hope it stays that way.