Mazama Energy Raises $135M to Drill 3 Miles Deep for Super-Hot Geothermal Power

TL;DR

• Mazama Energy has raised $135M in Khosla Ventures-backed funding to commercialize super-hot rock geothermal drilled three miles underground.
• Its high-temperature drilling system targets 400°C-plus rock to enable a single 15 MW well that can deliver 24/7 carbon-free power.
• The milestone funds a first commercial-scale demonstration and positions super-hot geothermal to scale like shale for data centers and the grid.

Khosla Doubles Down on Super-Hot Rock

Mazama Energy has closed a $135M financing round led by Khosla Ventures to take geothermal where no commercial power plant has gone before: three miles down into super-hot rock.

The raise marks one of the largest private investments to date in next-generation geothermal and signals growing investor confidence that deep, ultra-hot resources can deliver firm, round-the-clock clean electricity at a scale and cost that competes with natural gas.

The company plans to use the capital to prove its full drilling and power system in the field, expand its rig fleet, and advance development of its first commercial projects aimed at utilities and hyperscale data center customers hungry for 24/7 carbon-free power.

Why Three Miles Changes Everything

Conventional geothermal works only where hot water or steam naturally sits close to the surface — places like Iceland, Kenya, and California's Salton Sea. That limits it to less than 1% of U.S. land.

Mazama is chasing a different prize: super-hot rock found almost everywhere if you drill deep enough.

At depths of 15,000 feet or more, roughly three miles down, temperatures can exceed 400 degrees Celsius, or 750 degrees Fahrenheit. At those conditions water becomes supercritical — neither liquid nor gas — carrying 5 to 10 times more energy than conventional geothermal steam.

That energy density is why Mazama says a single 15 MW well could do the work of dozens of conventional geothermal or shale wells, powering roughly 11,000 to 15,000 homes from one borehole while using a fraction of the surface footprint of solar and wind.

Inside Mazama's Deep Drilling Playbook

Drilling three miles into 400°C-plus granite has broken every conventional drill bit and mud system tried so far. Mazama's breakthrough is a purpose-built system for extreme heat, pressure, and hard abrasive rock.

At the core is high-temperature, diamond-enhanced drilling hardware rated for super-hot conditions where standard electronics and elastomers melt. The company pairs it with specially formulated drilling fluids that remain stable at extreme temperatures and prevent wellbore collapse, plus advanced loss-circulation controls to handle the fractured volcanic rock typical of super-hot zones.

Crucially, Mazama drills without needing to find a natural underground reservoir. Instead, it creates an engineered heat exchanger by stimulating fractures in the hot dry rock, circulating water down to flash to superheated, supercritical steam, and bringing it back up to drive a turbine.

The approach borrows heavily from innovations in horizontal shale drilling and oilfield automation — faster penetration rates, real-time downhole sensing, and predictive control — but re-engineered for temperatures twice as hot as an oil well.

Why One 15 MW Well Matters

For geothermal, power output per well is the whole ballgame.

A typical conventional geothermal well produces 3 to 5 MW. An enhanced geothermal well from startups like Fervo Energy produces around 3 to 6 MW. At 15 MW per well, Mazama would triple that output, slashing the number of wells, pads, and drilling days needed for a 100 MW-plus power plant.

More power per well means dramatically lower levelized cost of electricity, faster project build times, and far less land and water use. And unlike solar and wind, a super-hot plant runs at 90%-plus capacity factor, delivering baseload power day and night, winter and summer.

For utilities balancing renewables and for AI data centers that need 50 to 500 MW of uninterrupted power in one location, that firm profile is the key selling point.

What $135M Unlocks Next

The new funding moves Mazama from lab and pilot-scale drilling into commercial demonstration.

Immediate priorities include drilling and completing its deepest, hottest well to date, demonstrating sustained supercritical flow and power generation, and de-risking well construction costs and timelines for future developments.

Longer term, the company is scouting sites in the western U.S. with high heat flow and favorable geology for its first 15 to 50 MW commercial plants, with a roadmap to 100 MW-plus super-hot developments by the end of the decade.

If successful, Mazama believes its wells can be replicated in a factory-like model across the U.S. and globally — no volcano required — turning deep heat into a ubiquitous, always-on energy source.

The Road to Geothermal at Shale Scale

Mazama is not alone. Fervo, Quaise, Sage Geosystems, and Eavor are all racing to make next-gen geothermal cheap and scalable, while the Department of Energy is pushing a goal of 90 GW of U.S. geothermal by 2050.

What sets the super-hot path apart is raw thermodynamics: hotter resource equals more power per dollar of steel and drilling.

Challenges remain — proving long-term reservoir performance, managing corrosion and silica scaling from supercritical fluids, and bringing deep drilling costs down the learning curve. But with $135M in fresh capital and Khosla's backing, Mazama now has the runway to find out if three miles down is where clean firm power finally scales.

AndroGuider Team

Articles written by the AndroGuider team. We try to make them thorough and informational while being easy to read.