Mazama Energy raises $135M Series B to drill 15 MW super-hot-rock geothermal wells

The funding

Geothermal startup Mazama Energy has closed a $135 million Series B, TechCrunch reported on Thursday. The round was oversubscribed and led by Centaurus Capital and Doerr Capital, with ConocoPhillips and Shell Ventures participating. Existing investors Khosla Ventures — where the company was incubated — and Gates Frontier returned, and new backers SiteGround Capital, H. Barton Asset Management and the Jeffrey and Marieke Rothschild Foundation joined.

What the money buys

According to TechCrunch, the capital will fund the development of horizontal wells in super-hot rock, each designed to generate up to 15 megawatts of electricity. Mazama has already drilled past 10,000 feet in 15 days at its first site and is working toward a final depth of roughly 15,000 feet.

At those depths the company can access rock at around 750°F (400°C). Under high pressure, water exposed to that heat becomes a supercritical fluid — a state between liquid and gas that can carry far more energy than ordinary steam. Mazama says this should allow each well to produce up to ten times more power than traditional geothermal technologies.

Timeline and site plans

Mazama expects to begin generating electricity sometime next year at its first site in Oregon, which the company now says is capable of producing 10 gigawatts. That is a sharp increase from the 5 gigawatts that investor Vinod Khosla estimated for the same site last year, as TechCrunch points out. The startup has already secured land for a second development and aims to complete buildout of the first site by 2030, when it expects the location to deliver 200 megawatts.

The competitive backdrop

Enhanced geothermal companies are emerging as an unexpected contender in the race to power AI data centers and other large grid loads, TechCrunch reports. Tech firms and data center developers have leaned heavily on natural gas for near-term capacity, but geothermal startups have been advancing their technology quickly, and the depth and heat they now target put far more energy within reach than earlier projects.

Why it matters

The round's investor list is itself a signal: with ConocoPhillips and Shell Ventures on the cap table alongside climate-focused funds, incumbent energy players appear to see a credible commercial path for super-hot-rock geothermal.

The economics hinge on per-well output. Conventional geothermal wells produce relatively modest amounts of power, which has historically confined the resource to geologically favorable spots. If wells in 400°C rock really can deliver 15 megawatts each, drilling costs are spread over far more capacity and the resource becomes viable across a much wider footprint. Research cited by TechCrunch from the University of Twente and the Clean Air Task Force estimates that tapping just 1% of the world's super-hot rock could generate more than 63 terawatts of electricity.

For data center operators, the appeal is firm, carbon-free capacity that runs around the clock regardless of weather — a complement to wind and solar rather than a substitute. Mazama still has to prove its claims at commercial scale, and its schedule, with first power next year and a 200-megawatt site by 2030, allows little slack. But if the Oregon project performs as projected, it would strengthen the case that deep geothermal can supply baseload power for the next wave of computing infrastructure.