In Search of Supercriticality
Two years ago, Mazama Energy inherited a dormant dream: 17 years of failed attempts to crack the Newberry Volcano, abandoned wells, and mounting skepticism about whether superhot rock geothermal could ever work. This October, they drilled two miles into the flank of the Oregon complex and hit 629°F, earning a new global record. Now comes the hard part.
The dream: Geothermal has long been the tantalizing also-ran of clean energy: baseload power, no intermittency, minimal land footprint, heat that never runs out. And yet it supplies <0.5% of U.S. electricity. Lackluster adoption comes down to geology and drilling economics: most of Earth’s heat is simply locked too deep to access profitably.
The physics: At 750°F, water enters a supercritical state: it flows like gas but carries heat like liquid, yielding 5-10× the power output of a conventional geothermal well. The supercritical regime (much higher power output per borehole) is what Mazama, backed by Khosla Ventures, Gates Frontier, and DOE, is after.
A geologist’s arb: Newberry’s value is its thermal gradient. Most crustal rock requires drilling 12+ miles deep to reach supercritical temperatures; here, you can hit 750° at under three.
Hardcore thermal management: To withstand downhole conditions that would cook standard oilfield electronics, Mazama cools its drill strings with liquid CO₂ that protects its sensor packages during their 2-mile dive through granite, basalt, and granodiorite. In October’s test, the team hit 100+ ft/hr penetration rates with zero downhole failures.
Now for the part frontier tech founders know all too well…
Mazama has proven the basic technique. Now they have to productionize it. A 15 MW pilot is planned for next year; Newberry has a theoretical capacity of ~5 GW, enough to supply two-thirds of Oregon’s electricity from a single geological feature. But bridging the gap between “theoretical capacity” and “commercially viable power” means answering more hard questions around unit economics across dozens of wells, the technology’s reliability, reservoir consistency, and so on.
Seventeen years of false starts at Newberry suggest humility. But Mazama’s October campaign delivered something the previous attempts didn’t: working hardware at temperature. That’s real, as is the bid from hyperscale datacenters scouring the West for a stable supply of scalable, clean power.