Digging into Nuclear Fusion Technology to Tap Geothermal
With roots in MIT fusion research, Quaise is betting on millimeter wave drilling to make geothermal a global power source, not just a regional advantage.
Written by Nancy Kristof
NATURALLY OCCURRING GEOTHERMAL ENERGY is a clean, reliable, and cost-effective energy source—if you can get to it.
Nuclear fusion research is helping advance drilling technology, pushing its viability beyond the conventional “Goldilocks” locations. Those areas have a specific set of characteristics—heat, permeability, and fluid—typically found near volcanic hydrothermal activity in places such as Iceland and Kenya, two of the world’s top producing geothermal energy countries.
“It’s a great resource, it’s clean, it’s an ‘always on’ baseload resource of energy, but it’s pretty regionally constrained,” said Matthew Houde, co-founder of Quaise Energy, a geothermal energy spinoff born out of MIT’s Plasma Science and Fusion Center. Founded in 2018, the company leveraged nuclear fusion research developed by MIT’s Paul Waskoff more than 15 years ago.
Waskoff had wondered if the technology could be applied to drilling and performed low power experiments to demonstrate the fundamentals with the help of some initial grant funding, said Houde. Houde and Quaise co-founder Carlos Araki met with Waskoff to explore how millimeter wave technology could be further developed to drill geothermal wells cheaper and faster.
Quaise’s Nabors rig and its millimeter wave drilling equipment integrated onto an existing onshore drilling rig for a yard test in Q2 2025. In 2026, the company will integrate a megawatt-scale millimeter wave drilling system onto the Nabors rig, making it Quaise’s first commercial prototype that can mobilize to its geothermal project and conduct the first full-scale demonstration of geothermal drilling. Photo: Quaise Energy
The cost and technical difficulty of conventional drilling increases exponentially as you go deeper, said Houde, and that has been holding geothermal energy development back from broader adoption.
Millimeter wave technology’s ability to more effectively reach “superhot geothermal” may help make geothermal energy a solution for a broader range of geographic areas with higher population density, he said. Much of the geothermal energy capture growth happening in the U.S. in the last 20 years has been in Nevada and western Utah.
“We saw this as a gating technology that can allow a developer like Quaise to develop geothermal projects economically in locations where geothermal isn’t even a part of the consideration as a potential energy solution,” Houde said.
“Our intent isn’t just to be a provider of technology or drilling services, but we actually want to leverage the drilling technology to enable us to develop these geothermal projects at greater depths and temperatures than what’s being done today,” he said.
“We initially received a $5 million grant from ARPA-E [Advanced Research Projects Agency–Energy] to execute the next phase of demonstration work in the lab and testing this drilling approach at higher power levels and at greater scales than what MIT previously achieved,” Houde shared. The company then raised $40 million in Series A funding (later expanded to $52 million), while performing testing at Oak Ridge National Laboratory, bringing total funding to about $63 million by mid-2022.
“Like the tortoise beating the hare, we can drill at a steady, constant speed independent of depth in the rock type.”
—Matthew Houde, co-founder of Quaise Energy, a geothermal energy spinoff born out of MIT’s Plasma Science and Fusion Center
Houde said one of their biggest challenges wasn’t figuring out the drilling process but rather securing equipment that could operate reliably during testing.
The capital investments enabled the firm to buy its own high-powered gyrotron systems to perform in-house testing at its facility in Houston. The company had its own high-power system operating in the lab by 2024.
Houde shared that the company’s progress has been dramatic: from drilling a one-inch hole through about nine feet of rock at a very slow rate of penetration to, just a year later, “drilling a four-inch diameter hole greater than 100 meters underground at about 10 to 100 times the speed.”
The compact millimeter wave drilling rig that Quaise mobilized to Marble Falls, Texas, in 2025 for its first field trial of millimeter wave drilling. The team successfully drilled 100 meters into a granite quarry. This photo shows a yard test that was conducted at the company’s engineering center in Houston. Photo: Quaise Energy
“We’ve really been able to rapidly scale the drilling performance as we’ve gotten equipment that’s new and operates reliably into our specifications,” he said.
Quaise’s approach maintains conventional drilling at surface levels. “We don’t think we need to reinvent the wheel in shallower, colder rock, where conventional drilling is very effective and very cheap,” Houde said.
Once conventional drilling reaches uniformly crystalline hard and hot rock—typically referred to as basement rock—it starts to decline in performance, taking longer and requiring tedious maintenance to remove pipe and replace drill bits.
“At that point, we take the traditional drill string out of the hole, case the hole, purge it, and introduce our millimeter wave drill string, which is actually a simple metallic pipe called waveguide,” Houde said. The gyrotron generates high-powered microwaves in a millimeter wavelength range at the surface. That energy is sent down the hole through a pipe with purge gas, Houde said.
“We’re injecting either compressed air or nitrogen and the microwaves, once they get to the bottom of the hole, are absorbed by the rock. The rock rapidly heats up, and then we are able to drill through that rock by either spalling it, melting it, or even potentially vaporizing the rock,” Houde said. The gas that circulates down the hole removes the rock cuttings and conveys them up to the surface, he explained. “The process doesn’t really care that the rock is getting harder or the rock is getting hotter. It sees the rock mostly the same,” Houde said. “It should be a much more linear process drilling deeper with millimeter wave drilling compared to conventional drilling, where cost and technical difficulty increase exponentially as you go deeper.”
The gyrotron—a microwave generator and source of Quaise’s millimeter wave beam—inside its container. Photo: Quaise Energy
Though millimeter wave drilling may not be as fast as conventional drilling is at shallow depths, “like the tortoise beating the hare, we can drill at a steady, constant speed independent of depth in the rock type,” Houde said.
The company plans to use this drilling technology at greater depths and temperatures than what’s being done today to develop its own “first-of-its-kind” geothermal project, “somewhere in the western U.S.”
Houde said that instead of accessing a naturally occurring geothermal system, which is how geothermal produces power today, Quaise is pursuing sites where there aren’t as favorable geothermal conditions in the long term.
“We use millimeter wave drilling to drill very deep and into these superhot temperatures. We then use fracturing to create an EGS [enhanced geothermal system] reservoir, and we’re able to sustainably harvest and produce that heat and energy over the lifetime of a well field, or power plant,” he said.
Houde credits MIT’s leadership and investment in nuclear fusion research to creating these opportunities for commercial applications. “There’s a lesson that sometimes the technology that gets developed through this academic research has an application in an entirely different market than what it was initially conceived for,” he said.
Nancy Kristof is a technology writer in Denver.
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