Quaise Energy, a Houston and California-based geothermal startup, announced the first close of a $134 million Series B round in July 2026, led by Prelude Ventures with strategic backing from Japanese energy majors JERA and Idemitsu.
The company is developing drilling technology using ultra-high-frequency millimeter waves capable of boring up to 15 kilometers into the Earth's crust -- deep enough to reach superhot geothermal reservoirs exceeding 400 degrees Celsius that could, in principle, power base-load electricity plants almost anywhere on the planet, not just in regions with naturally accessible geothermal activity like Iceland or parts of the western United States.
The round adds to a wave of large climate and energy infrastructure deals in July 2026, arriving the same week as Munich-based Proxima Fusion's roughly $468 million raise for its stellarator fusion reactor. Together, the two rounds point to a consistent theme: major energy players and strategic investors are placing serious, long-duration bets on next-generation power generation technologies capable of meeting the enormous and growing electricity demands of AI data centers and industrial compute.
For founders in climate tech and energy infrastructure, Quaise's raise underscores that investors are willing to fund genuinely difficult, multi-year hard-science bets when the payoff -- reliable, geographically flexible baseload power -- addresses a problem urgent enough for strategic energy companies to co-invest directly rather than wait for the technology to mature elsewhere.