Mazama Energy Raises $135 Million in Series B Led by Centaurus Capital and Doerr Capital

Mazama Energy announced on September 17 that it secured $135 million in new capital, including a Series B round led by Centaurus Capital and Doerr Capital. ConocoPhillips and Shell Ventures also joined the financing. Existing investors Khosla Ventures and Gates Frontier continued their support, while SiteGround Capital, H. Barton Asset Management, and the Jeffrey and Marieke Rothschild Foundation contributed fresh equity. The funds will be allocated to expand the company’s engineered geothermal system that targets super‑hot rock formations, a domain it describes as the world’s hottest artificial geothermal site.

The project aims to drill deeper into dry, super‑hot rock masses, create artificial flow pathways where natural reservoirs are absent, and efficiently extract heat for power generation. Current drilling at the Athena well in Newberry, Oregon, has reached 10,350 feet in 15 days, targeting a final depth of about 15,500 feet where temperatures exceed 750°F. The company claims the site achieves a record temperature of 629°F (331°C), demonstrating the ability to create reservoirs, connect wells, and recover heat in practice.

By operating in the super‑critical water regime above 705°F, the system is expected to deliver up to ten times the output of conventional wells, reducing the number of wells needed by 80% and water usage by 75%, thereby shrinking overall project scale including surface facilities. The funding round was reported by BRIDGE.