A geothermal startup backed by Khosla Ventures, Mazama Energy, has secured $135 million in an oversubscribed Series B funding round. The capital will be used to develop horizontal wells targeting super-hot rock formations, with the goal of generating 15 megawatts of electricity per well.
Mazama plans to commence electricity generation next year. Its initial site in Oregon is projected to have a capacity of 10 gigawatts, a significant increase from the 5 gigawatts estimated last year.
Enhanced geothermal startups are emerging as a key player in the energy sector, particularly for powering AI data centers and other high-demand loads. While many tech companies are focusing on natural gas, geothermal startups are rapidly advancing their technologies.
Mazama's approach involves targeting deeper and hotter rock formations than traditional geothermal projects. The company has drilled past 10,000 feet, reaching depths of approximately 15,000 feet, where temperatures reach 750° F (400° C). At these high pressures, water becomes a "supercritical" fluid, capable of absorbing significantly more energy than steam, allowing each well to produce up to ten times more power than conventional geothermal technologies.
Globally, tapping into super-hot rock resources could generate over 63 terawatts of electricity, according to the University of Twente and the Clean Air Task Force.
While the Oregon site is still in its early stages, Mazama has already secured land for a second development. The company aims to complete the first site by 2030, expecting it to generate 200 megawatts of electricity.
The funding round was led by Centaurus Capital and Doerr Capital, with participation from ConocoPhillips and Shell Ventures. Khosla Ventures and Gates Frontier reinvested, joined by new investors SiteGround Capital, H. Barton Asset Management, and the Jeffrey and Marieke Rothschild Foundation. Mazama Energy was initially incubated at Khosla Ventures.
