US-based Quaise Energy has raised $134m in the first close of its Series B financing, which will support its plans to build Project Obsidian, a commercial superhot geothermal power plant.

Project Obsidian is currently under construction in the Deschutes National Forest in Oregon.

The project is expected to deliver electricity to the grid by 2030.

The Series B round was led by Prelude Ventures, with strategic investors including JERA Co. and Idemitsu Kosan, two Japanese energy companies. Most existing investors, including Safar Partners, also joined the funding round.

Project Obsidian is located on federal geothermal leases in Oregon and is described as having gigawatt-scale potential.

The facility aims to help meet rising energy demand and address transmission constraints in the Pacific Northwest.

Quaise Energy expects to secure further equity and debt capital soon, alongside additional project-level financing that is being raised in parallel. To date, the company has secured $230m in total funding.

The company develops utility-scale superhot geothermal energy by deploying a millimetre wave drilling system, a technology originally developed at the Massachusetts Institute of Technology.

This system is designed to ablate rock at greater depths and temperatures than those accessible with conventional drilling equipment, potentially accessing subterranean temperatures between 300°C and 500°C worldwide.

The technology was demonstrated at the company’s field site in central Texas in 2025, where it drilled more than 100m through granite.

Quaise Energy reports it is close to reaching a depth of 1km at the same location, marking what it says would be the deepest penetration ever achieved using millimetre wave drilling, or any non-contact drilling method.

Quaise Energy CEO and president Carlos Araque said: “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.”

Quaise Energy’s technology is being further developed for broader commercial deployment, with the company planning to announce additional financing arrangements later this year.