US geothermal energy company pilot shows 24/7 carbon-free power production possible

Advanced geothermal company Fervo Energy has successfully tested horizontal drilling technology pioneered by the oil and gas industry, setting records for both flow and power output from an enhanced geothermal system, and allowing 24/7 carbon-free power production, the company said July 18.

"By applying drilling technology from the oil and gas industry, we have proven that we can produce 24/7 carbon-free energy resources in new geographies across the world," Tim Latimer, Fervo Energy CEO and co-Founder, said in a statement.

"The incredible results we share today are the product of many years of dedicated work and commitment from Fervo employees and industry partners, especially Google," Latimer said.

Firm, zero-carbon, dispatchable resources are needed to fully decarbonize the electricity sector and "geothermal power can play that role," according to a research paper that Fervo submitted to the open scholarly communication tool, EarthArXiv, on July 18.

According to the US Department of Energy's GeoVision Study and EarthShot Initiative, breakthroughs in enhanced geothermal system technologies could unlock over 100 GW of clean, firm power across the country, the paper said.

Leveraging technology innovations from the unconventional oil and gas industry provides a pathway to access new geologic resources and improve project economics in a way that could "enable geothermal developers to mimic the rapid scale-up observed in shale development over the past two decades," Fervo said in the paper.

Pilot project

The company completed the well test at its full-scale commercial pilot, called Project Red, in northern Nevada. The 30-day well test achieved a flowrate of 63 liters/second at high temperature enabling 3.5 MW of electric production, Fervo said in the statement.

Data collected as part of the pilot project "will enable rapid advancement in geothermal deployment," with the company's next horizontal well pair planned to achieve more than double the power output of the pilot design, according to the statement.

In 2021, Fervo and Google signed the "world's first corporate agreement" to develop advanced geothermal power with the goal of the partnership being to power Google's Cloud region in Las Vegas with an "always-on," carbon-free resource that will reduce the company's hourly reliance on fossil fuels, Fervo said.

"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, senior director for Energy and Climate at Google, said.

"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," Terrell said.

The pilot site is located adjacent to the Blue Mountain geothermal power plant in northern Nevada, owned by Cyrq Energy. The plant has a capacity of 39 MW and can annually generate 240,000 MWh of power, according to the DOE.

Fervo's project delivered an uplift in high-temperature geothermal flow rates to increase the power capacity at the facility, the research paper said.

Specifically, the project involved designing and constructing a three-well drilling program, including two horizontal wells that formed an injection and production doublet system and a deep vertical monitoring well.

"In successfully completing this project, we have demonstrated that no major technical barriers exist to deploying horizontal EGS systems in similar metasedimentary or igneous formations up to temperatures of approximately 400 degrees Fahrenheit," the company said in the paper.

Data from the project demonstrates a "clear innovation pathway" to increasing the power capacity up to 8 MW of electric power per production well, Fervo said.

The pilot project results support the findings of the DOE's Enhanced Geothermal Earthshot and show that geothermal energy could supply over 20% of US power demand and compliment wind and solar power to reach a fully decarbonized grid, the company said.

US oil and gas producer Devon Energy said July 18 that it has made a $10 million strategic investment in Fervo.

"This investment is a good match for Devon's new energy ventures strategy," David Harris, Devon's chief corporate development officer and executive vice president, said in a statement.