'Breakthrough' geothermal tech produces 3.5 megawatts of carbon-free power

Fervo Energy says it has achieved a breakthrough in geothermal technology. It carried out a 30-day well test at its site in northern Nevada and says it was able to achieve a "flowrate of 63 liters per second at high temperature that enables 3.5 megawatts of electric production." The company says the test resulted in flow and power output records for an enhanced geothermal system (EGS) and that it was completed without incident.

A megawatt can power around 750 homes at once. Fervo is expected to connect its Project Red site to the grid this year. It will be used to power Google data centers and some of the company's other Nevada infrastructure. Google and Fervo signed an agreement in 2021 to develop a "next-generation geothermal power project."

This is the first time an energy company has shown that an EGS can work on a commercial scale, according to Bloomberg. It's been a long road to reach this point, as scientists have been trying to make EGS a reality since the 1970s.

For a natural geothermal system to produce electricity, it needs a combination of heat, fluid and rock permeability, as Bloomberg notes. In many areas, the rock has the required levels of heat, but not enough permeability for fluid to flow through it.

An EGS creates this permeability artificially by drilling deep underground and injecting fluid to create fractures in the rock. That approach can vastly increase the number of potential sites for a geothermal power plant.

Fervo says it's the first company to "successfully drill a horizontal well pair for commercial geothermal production, achieving lateral lengths of 3,250 feet, reaching a temperature of 191°C, and proving controlled flow through rigorous tracer testing."

One of the major advantages of geothermal power plants is that they're entirely carbon free — Google aims to run all of its offices and data centers on carbon-free energy by 2030. These plants can also operate at any time (unlike solar and wind), making geothermal energy a compelling source of renewable power. However, cost reductions and regulatory red tape are barriers to making EGS more broadly available, according to Fervo CEO Tim Latimer.

The company is hoping to replicate its success at a site in Utah. If Fervo sees similar results there and it successfully implements design upgrades to maximize output, the site is expected to generate enough electricity to power 300,000 homes simultaneously, Latimer said. That's around a quarter of all homes in Utah.

“Achieving our goal of operating on 24/7 carbon-free energy will require new sources of firm, clean power to complement variable renewables like wind and solar,” Michael Terrell, Google's senior director for energy and climate, said in a statement. “We partnered with Fervo in 2021 because we see significant potential for their geothermal technology to unlock a critical source of 24/7 carbon-free energy at scale, and we are thrilled to see Fervo reach this important technical milestone.”