Mazama Energy Raises $135 Million to Scale Superhot Rock Geothermal Power in Oregon
Mazama Energy raised $135 million on September 17, 2026, to scale its superhot rock geothermal system toward 750°F at Oregon’s Newberry Volcano.
Photo by Yuan on Pexels
Mazama Energy said on September 17, 2026, that it raised $135 million in new capital, including an oversubscribed Series B round, to accelerate development of its superhot rock geothermal technology near Oregon’s Newberry Volcano. The Mazama Energy superhot geothermal funding round was led by Centaurus Capital, the investment firm of billionaire John Arnold, and Doerr Capital, with participation from oil and gas majors ConocoPhillips and Shell Ventures alongside repeat investors Khosla Ventures and Gates Frontier.
Additional investors in the round include SiteGround Capital, H. Barton Asset Management, and the Jeffrey and Marieke Rothschild Foundation, according to the company’s announcement. Canary Media, which interviewed Mazama’s chief executive ahead of the announcement, reported the same $135 million figure and investor list, corroborating the company’s release.
Drilling toward 750 degrees Fahrenheit
Mazama, which is based in Frisco, Texas, is developing enhanced geothermal systems (EGS) that extract heat from hot, dry rock rather than relying on naturally occurring hot water reservoirs. In 2025, the company said it built the hottest engineered geothermal system ever recorded, reaching 629 degrees Fahrenheit (331 degrees Celsius) at its Newberry Volcano pilot site. The project received a grant from the U.S. Department of Energy.
The company’s second well, called Athena, reached the same 10,350-foot depth this month in 15 drilling days, about 80% faster than the 2025 well, and is continuing deeper toward a target of 750 degrees Fahrenheit (400 degrees Celsius). Mazama says reaching that temperature would deliver up to 10 times the power output of a conventional 390-degree-Fahrenheit (200-degree-Celsius) geothermal well, while using 75% less water and 80% fewer wells than conventional geothermal projects, because of the higher energy density of supercritical water and improved reservoir productivity at extreme temperatures.
| Milestone | Detail |
|---|---|
| 2025 record | 629°F (331°C) engineered geothermal system at Newberry, Oregon |
| Second well (Athena) depth | 10,350 feet, reached in 15 days (about 80% faster than 2025 well) |
| Target temperature | 750°F (400°C) |
| Power multiplier at target | Up to 10x a conventional 390°F (200°C) well |
| Resource use vs. conventional geothermal | 75% less water; 80% fewer wells |
| New funding | $135 million (oversubscribed Series B plus additional investors) |
| Resource potential targeted for certification | More than 10 GWe at Newberry alone |
Source: Mazama Energy (GlobeNewswire), September 17, 2026.
Funding will support Project Ceres, backed by the DOE
The new capital funds Mazama’s next initiative, Project Ceres, which is supported by the U.S. Department of Energy. The project involves drilling horizontal wells in superhot rock to demonstrate roughly 15 megawatts of electric capacity per well, with power generation testing planned for 2027, according to the company. Mazama said it is targeting independent certification of more than 10 gigawatts of electric resource potential at Newberry alone, while evaluating additional sites in the United States and internationally.
“The breakthrough in superhot geothermal is turning extreme heat into a repeatable, economic power system,” said Sriram Vasantharajan, Mazama’s chief executive, in the company’s announcement. Vasantharajan is a chemical engineer who previously worked on complex oil and gas wells, including deep-water and heavy petroleum reservoirs, before Mazama launched in 2023.
John Arnold of Centaurus Capital said in the release that “superhot geothermal offers the promise of firm, carbon-free power with a relatively small footprint, but realizing that promise requires significant technical innovation,” adding that “Mazama has made impressive progress.” Vinod Khosla of Khosla Ventures said scaling toward 400 degrees Celsius means “ten times the heat from a fifth of the wells and a fraction of the water.”
Part of a broader superhot geothermal funding wave
Mazama’s raise follows a string of financings and milestones among companies pursuing next-generation geothermal power. Fervo Energy went public earlier in 2026, and its Utah project subsequently signed a large power-purchase agreement with Google. Sage Geosystems recently began producing power from its first pilot system in Texas. Quaise Energy, which is also drilling a geothermal well near Newberry Volcano, closed a $180 million Series B funding round in August 2026, according to Canary Media.
Winss Solutions has tracked this sector’s growth, including Sage Geosystems bringing its first geothermal plant online in Texas, Fervo Energy’s 396 MW enhanced geothermal power deal with Google for a Utah data center, and Quaise Energy’s funding for the first commercial superhot geothermal energy plant. Conventional geothermal plants, which rely on naturally occurring hot water reservoirs, are geographically limited; enhanced geothermal systems aim to unlock heat from hot, dry rock in far more locations, a shift Winss Solutions examined in The Future of Geothermal Drilling: What the Next Two Decades Will Bring.
About Mazama Energy
Mazama Energy launched in 2023 with the goal of developing drilling tools and techniques to extract heat from superhot, dry rock environments. The company, based in Frisco, Texas, is led by chief executive Sriram Vasantharajan, a chemical engineer with a background in complex oil and gas well engineering. In 2025, Mazama drilled what it says is the hottest engineered geothermal system built to date, reaching 629 degrees Fahrenheit (331 degrees Celsius) at a pilot site near Newberry Volcano in central Oregon, a project supported by a U.S. Department of Energy grant. The company says its approach can generate substantially more power from fewer wells than conventional geothermal methods, using less land, water and capital. With the September 17, 2026 financing round, Mazama is advancing Project Ceres, a DOE-backed effort to demonstrate horizontal-well power generation in 2027 as it works toward certifying more than 10 gigawatts of electric resource potential at Newberry and evaluating additional sites in the U.S. and abroad.
Sources: Mazama Energy (GlobeNewswire); Canary Media
Featured image: photo by Yuan on Pexels (free Pexels license).
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I specialize in sustainability education, curriculum co-creation, and early-stage project strategy. At WINSS, I craft articles on sustainability, transformative AI, and related topics. When I’m not writing, you’ll find me chasing the perfect sushi roll, exploring cities around the globe, or unwinding with my dog Puffy — the world’s most loyal sidekick.
