Mazama Energy Raises $135M to Push Super-Hot-Rock Geothermal Deeper

Mazama Energy raised $135 million in an oversubscribed Series B, according to TechCrunch. The funding is aimed at developing horizontal wells in super-hot rock that the company says can generate 15 megawatts of electricity per well. For readers tracking clean power for heavy electricity demand, the key takeaway is that Mazama is moving from drilling progress toward power production plans.

Mazama is targeting deeper, hotter rock than earlier geothermal projects, drilling past 10,000 feet in 15 days on the way to about 15,000 feet. At those depths, the company says it can access 750°F, or 400°C, heat that turns water under high pressure into a supercritical fluid. Mazama says that state lets each well produce up to 10 times more power than traditional geothermal technologies.

Mazama plans to begin generating electricity sometime next year at its first site in Oregon. The company now says that site is capable of producing 10 gigawatts, up from a prior 5-gigawatt estimate cited by investor Vinod Khosla last year. Mazama aims to complete development of the first site by 2030, when it says the site should generate 200 megawatts, and it has already secured land for a second development.

TechCrunch frames enhanced geothermal startups as a potential “dark horse” in the race to power AI data centers and other large grid loads. While tech companies and data center developers have backed natural gas, geothermal startups are advancing technology that could provide around-the-clock clean power. The broader upside is significant: tapping just 1% of super-hot rock worldwide could generate more than 63 terawatts of electricity, according to the University of Twente and the Clean Air Task Force.

The Series B was led by Centaurus Capital and Doerr Capital, with participation from ConocoPhillips and Shell Ventures. Existing investors Khosla Ventures and Gates Frontier returned, while SiteGround Capital, H. Barton Asset Management, and the Jeffrey and Marieke Rothschild Foundation joined as new investors. Mazama was incubated at Khosla Ventures.