A new initiative from a group of veterans in the oil industry aims to rejuvenate one of California’s pivotal clean energy resources amidst a decline in terminal facilities.
Greenfire Energy announced on Thursday that it is reviving operations at the Geysers, known as the largest geothermal power plant globally, which has been in steady decline for years.
The Greenfire team has revamped wells that previously struggled with electricity production. Instead of hastily injecting water, their approach utilizes technology designed to harness underground heat.
This offers a potential solution for the Geysers, which currently generates approximately 630 megawatts of carbon-free power for Northern California, a significant drop from the 2,000 megawatts produced in 1987.
“You can spot these grey wells—they’re mostly abandoned,” remarked Rob Krenner, a former oil and gas engineer who now heads Greenfire. “There’s still some heat in the area, but it’s like a dry oil well,” he elaborated, implying that the remaining resources are inadequate to maintain operations.
The decline is largely attributed to the rapid depletion of water in traditional geothermal setups.
Currently, Geysers facilities utilize around 15 million gallons of water daily—roughly the equivalent of 22 Olympic-sized swimming pools. The 18 facilities across the 45-mile complex generate energy using steam to turn turbines.
This steam primarily comes from treated urban wastewater, a method that unfortunately leads to significant water loss, especially in a region facing considerable water stress, thus limiting hot water fields’ productivity.
Greenfire’s new power plants are focusing on wells that had been largely forgotten due to low pressure, employing techniques that generate electricity while conserving water.
Rather than using heated water in a way that results in significant atmospheric loss, their strategy involves maintaining enough water to restore pressure and sealing the well effectively.
As steam rises from the heated rocks below, it enters an innovative power plant system known as the Organic Rankine Cycle (ORC). This closed-loop system operates with “working fluids” that vaporize at temperatures lower than water.
Hydraulic fluid circulates through pipes to spin the turbine, generating power. The heat is released in the condenser, returning the fluid to the pump to repeat the cycle.
Krenner compared this to existing oil extraction methods, explaining that steam heats the system while excess fluid is reinjected underground, thus minimizing surface discharge.
With growing interest in enhanced geothermal systems (EGS) that leverage technologies like fracking to develop artificial networks underground, Krenner sees potential in reviving existing resources rather than starting anew.
Proponents of EGS envision geothermal drilling at a scale that mirrors the oil and gas boom of the previous decade. Greenfire is pursuing its own EGS project, but Krenner emphasizes the need for it to create power at novel sites while connecting to existing grids.
At the Geysers, he explained, “All the infrastructure is in place. We have the wells, power lines, and are operating in a well-established area. We aim to be the first to successfully accomplish this under such circumstances.”
He mentioned that restoring the Geysers to its former productivity level could be like adding gigawatts to the energy grid—akin to deploying hundreds of new wind turbines without the complications of new construction.
“If we can achieve this with existing wells and potentially double our output, there lies a tremendous opportunity,” he concluded.
