US-based geothermal energy technology company Quaise Energy has raised $134 million (approximately €112 million) at the first close of a Series B funding round to support the development of Project Obsidian, the world's first commercial superhot geothermal power plant, located on federal geothermal leases in the Deschutes National Forest in Oregon.

As reported by ESG Today, the round was led by Prelude Ventures, with strategic investments from Japanese energy companies JERA and Idemitsu alongside nearly all existing investors. The $134 million represents the initial equity component of a broader capital programme, with Quaise having raised $230 million in total to date. The company expects to announce additional project-level equity and debt financing later this year.

Carlos Araque, CEO and President of Quaise Energy, said: "Our ambition is to power civilization with Earth's most compelling energy source. This round takes us from field-proven technology to first commercial revenues."

Mark Cupta, Managing Director at Prelude Ventures, said: "We have backed Quaise since the beginning because we believed accessing superhot rock would unlock geothermal energy at a scale the world has never seen. What the team has achieved in the field and what they are now building at Project Obsidian validates that conviction, and we are proud to continue supporting Quaise as they move from proving the technology to powering the grid with clean, reliable energy nearly anywhere on Earth."

Founded in 2018 as a spinout from the Massachusetts Institute of Technology, Cambridge-based Quaise develops millimeter-wave drilling technology designed to access geothermal resources at depths and temperatures beyond the reach of conventional drilling methods, with the potential to reach rock at temperatures of 300 to 500°C in most locations worldwide.

Project Obsidian is sited at one of the most studied geothermal locations in the United States and carries gigawatt-scale potential. The project is expected to begin delivering electricity to the grid by 2030, supporting grid reliability in the Pacific Northwest amid rising electricity demand and transmission constraints driven by data centre expansion and industrial electrification.

Superhot geothermal energy, if successfully commercialised at scale, could provide continuous, dispatchable clean power without the intermittency challenges associated with solar and wind generation, positioning it as a significant long-duration baseload resource for decarbonising electricity grids globally.