Quaise Energy raises US$134 million in first close of Series B

The proceeds from Series B will fund Project Obsidian, the world’s first commercial superhot geothermal power plant, and the continued development and commercialisation of Quaise's millimeter wave drilling system towards depths in excess of 5 km. Project-level equity and debt financing is concurrently being raised as the company advances toward first revenues secured by yet-undisclosed commercial offtake partners. The Series B brings Quaise's total funding raised to date to US$230 million.

Quaise uses a millimeter wave drilling system developed at the Massachusetts Institute of Technology to ablate rock at depths and temperatures that are not economically accessible using conventional drilling. With this technology, Quaise has the unique potential to reach rock at temperatures of 300 – 500°C in most places worldwide, enabling the construction of geothermal systems that rival fossil and nuclear energy in power density and renewables in cost.

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

Quaise has demonstrated the capability of its millimeter wave drilling system at its Central Texas field site, drilling more than 100 meters through granite in 2025 – the first time the technology penetrated basement rock at full scale in field conditions. The company is now approaching one kilometer of depth at the same site, a milestone that would represent the deepest penetration ever achieved with millimeter wave drilling- and the deepest ever recorded by any non-contact drilling technology. These results validate the core technology that Quaise will deploy at Project Obsidian and at other sites as the company dramatically expands the map for geothermal.

“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,” said Mark Cupta, Managing Director at Prelude Ventures. “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.”

“Quaise's millimeter wave technology has the potential to redefine what geothermal can deliver – accessing heat at depths and temperatures that were previously out of reach. This investment reflects Idemitsu's commitment to next-generation energy solutions that can contribute to stable, sustainable power supply at scale,” said Kei Honda, Executive Leader, San Jose Office and Senior Vice President, Head of Corporate Venturing, Idemitsu Americas Holdings Corp.

Project Obsidian, where construction is currently underway, sits on federal geothermal leases in the Deschutes National Forest in Oregon, one of the most studied geothermal locations in the US. The project has gigawatt scale potential and will deliver first electrons to the grid by 2030. Power will support grid stability across the Pacific Northwest at a time when the region faces rising demand and constrained transmission capacity.

“As a global energy company, JERA understands both the scale of the challenge ahead and the scale of the opportunity that next-generation geothermal represents. Millimeter wave drilling technology has the potential to make geothermal a truly global baseload resource,” said Takeshi Kodama, Head of JERA Ventures and Managing Partner, JERA Co., Inc. “We look forward to working together with Quaise to advance the development of this promising technology and business.”

“We are proud to be a partner and supporter of Quaise Energy. As the need for power grows exponentially around the world, Safar believes geothermal energy has a critical role to play, and Quaise is uniquely positioned to revolutionise the industry,” said Parinaz Motamedy, Partner at Safar Partners. “By reimagining the drilling process entirely and leveraging millimeter wave technology to reach previously inaccessible depths and temperatures, Quaise is unlocking superhot geothermal energy at a global scale. We've been working alongside the team since the beginning, and this round represents an important inflection point as the company transitions from scientific breakthroughs to commercial deployments.”

The US$134 million Series B represents the initial equity component of a broader capital programme. Quaise has closed US$230 million to date. Additional components of the capital programme, including project-level equity and debt financing, are expected to be announced later this year.

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