Khosla-backed Mazama Energy raises $135 million to turn superhot rocks into clean power

### Mazama Energy Raises $135 Million to Scale Superhot Geothermal Power Technology

Geothermal energy startup Mazama Energy has raised $135 million in an oversubscribed Series B funding round as it moves toward commercializing a technology designed to generate electricity from extremely hot underground rock.

The funding round was led by Centaurus Capital and Doerr Capital, with participation from ConocoPhillips and Shell Ventures. Existing investors Khosla Ventures and Gates Frontier also contributed, while SiteGround Capital, H. Barton Asset Management, and the Jeffrey and Marieke Rothschild Foundation joined as new investors.

Mazama was originally incubated by Khosla Ventures and has focused its development efforts on enhanced geothermal systems that can operate at temperatures far beyond those used in conventional geothermal projects.

The company plans to use the new capital to develop horizontal wells in superhot rock formations. According to TechCrunch, each well could eventually generate as much as 15 megawatts of electricity, with Mazama targeting initial electricity production as early as next year.

Its first project site in Newberry, Oregon, has the potential to eventually produce up to 10 gigawatts of electricity, according to the company.

Mazama’s technology differs from traditional geothermal power, which generally relies on naturally occurring underground reservoirs of hot water or steam. Instead, the company drills deep into extremely hot rock and creates an engineered geothermal reservoir.

The company is drilling roughly three miles underground, where temperatures can exceed 400 degrees Celsius. Water can be injected into the engineered reservoir, heated by the surrounding rock and brought back to the surface as steam to generate electricity.

The approach is part of a broader effort to make geothermal power available in locations where naturally occurring geothermal reservoirs may not be sufficient for conventional projects.

Interest in the technology is also growing as major technology companies look for reliable sources of carbon-free electricity to support expanding data centers and artificial intelligence infrastructure. Unlike solar and wind generation, geothermal plants can potentially provide electricity continuously without depending on weather conditions.

Mazama is competing in an increasingly active enhanced-geothermal market. Fervo Energy, another geothermal technology company, has entered agreements involving Google, while Sage Geosystems is developing superhot-rock geothermal projects in Texas.

Mazama says its work at the Newberry site has already demonstrated the ability to create and operate an engineered geothermal system at exceptionally high temperatures. In 2025, the company reported operating a system at 629 degrees Fahrenheit, or about 331 degrees Celsius.

The company said the project demonstrated key elements including reservoir creation, underground connectivity and heat recovery under extreme-temperature conditions.

Mazama CEO Sriram Vasantharajan said the company’s objective is to turn superhot geothermal heat into a repeatable commercial power source. He pointed to the combination of high-temperature drilling, engineered reservoirs and heat recovery as the foundation for scaling the technology.

Khosla Ventures founder Vinod Khosla also highlighted the growing need for reliable electricity as industries expand their computing and infrastructure requirements.

Khosla said his firm invested in Mazama at an early stage because of geothermal energy’s potential to provide continuous clean power. He also pointed to the company’s progress toward operating at temperatures around 400 degrees Celsius.

According to Khosla, operating at those temperatures could allow geothermal developers to extract substantially more energy while requiring fewer wells and less water.

The $135 million financing gives Mazama additional capital to move from high-temperature demonstration projects toward commercial development. The company’s next phase will focus on improving drilling, reservoir performance and power-generation systems as it works toward its first electricity production.

If successful, superhot geothermal technology could expand the geographic reach of geothermal power and provide another source of round-the-clock electricity for growing industrial and digital energy demand.