Mazama Energy Raises $135M for 15 MW Super-Hot Geothermal Wells
Mazama Energy raised $135 million to develop super-hot geothermal wells, targeting 15 MW per well and 200 MW at its Oregon site by 2030, with power due in 2027.
Summary
As of September 18, 2026, Khosla Ventures-incubated Mazama Energy had raised $135 million in an oversubscribed Series B to develop horizontal wells in super-hot rock, targeting 15 megawatts per well. Centaurus Capital and Doerr Capital led, joined by ConocoPhillips, Shell Ventures, returning investors Khosla Ventures and Gates Frontier, plus SiteGround Capital, H. Barton Asset Management, and the Jeffrey and Marieke Rothschild Foundation. Mazama drilled beyond 10,000 feet in 15 days toward roughly 15,000 feet, where 750°F, or 400°C, rock and high pressure turn water into an energy-dense supercritical fluid. The company says this could produce up to 10 times more power per well than traditional geothermal technology.
Mazama expects electricity generation in 2027 and says its early-stage Oregon site holds 10 gigawatts of potential, double Vinod Khosla's 2025 estimate of 5 gigawatts. It aims to finish the first development and generate 200 megawatts by 2030, while land is secured for a second project. The University of Twente and Clean Air Task Force estimate that tapping 1% of global super-hot rock could produce more than 63 terawatts. Enhanced geothermal could serve AI data centers and other large grid loads, although tech companies and data center developers are also backing natural gas.
Positives
- $135 million from an oversubscribed Series B gives Mazama capital to develop horizontal super-hot geothermal wells.
- 15 megawatts per well would be up to 10 times the output of traditional geothermal technology.
- 10 gigawatts of estimated Oregon potential doubles Vinod Khosla's 2025 estimate of 5 gigawatts.
- 200 megawatts is targeted from the first Oregon development by 2030, with electricity generation expected in 2027.
- 63 terawatts could be generated by tapping just 1% of global super-hot rock, researchers estimate.
- 15 days were needed to drill beyond 10,000 feet, demonstrating rapid progress toward Mazama's roughly 15,000-foot target.
Risks & concerns
- Oregon development remains at an early stage, with commercial electricity not expected until sometime in 2027.
- 200 megawatts targeted by 2030 represents only a fraction of the Oregon site's claimed 10-gigawatt potential.
- Natural gas continues attracting support from tech companies and data center developers competing to secure power.
- 15-megawatt wells and tenfold output remain Mazama's projections as development continues.