MIT's Fusion Tech Could Unlock Deep Geothermal Energy Across America

Representative Jake Auchincloss (D-Mass) recently visited the MIT Plasma Science and Fusion Center (PSFC) to explore how fusion energy research could unlock a new era of geothermal power across the United States. The visit highlighted the unexpected synergy between two seemingly distinct energy technologies: high-temperature superconducting (HTS) magnets developed for fusion reactors and millimeter-wave drilling systems that could access superhot geothermal resources deep beneath the Earth's surface.

During his March 12 tour, Auchincloss learned how PSFC's breakthrough HTS magnet technology, which enables more compact and cost-effective fusion reactor designs by generating dramatically higher magnetic fields, shares fundamental principles with advanced drilling systems. The same technological foundation that allows fusion reactors to confine plasma more efficiently can also enhance gyrotrons—high-power microwave sources that operate more effectively at higher frequencies.

This microwave technology has found an unexpected application in geothermal energy through millimeter-wave drilling. Unlike conventional mechanical drilling that struggles with extreme depths and temperatures, millimeter-wave systems use focused microwave energy to heat, melt, or vaporize rock. The approach offers a crucial advantage: drilling rates scale directly with input power while costs increase less rapidly with depth compared to traditional methods. This could overcome the economic barriers that have historically limited geothermal development to geologically favorable regions like the western United States.

"Superhot geothermal uses microwaves to melt rock, going much deeper and hotter than is possible with contact drilling," Auchincloss explained. "This can generate clean, baseload power in America east of the Rocky Mountains, where the geology has conventionally not been suitable for industrial geothermal."

The technology's potential extends beyond energy generation. Auchincloss noted that while the approach may be years away from practical deployment in Massachusetts due to its "cool rock" geology, the economic benefits could be substantial. "In addition to lower utility bills, a new industry with good jobs could thrive here," he said, pointing to the growing ecosystem of MIT spinouts and their suppliers already establishing operations in Massachusetts.

Quaise Energy, an MIT startup with offices in Cambridge, demonstrated the technology's viability last fall with a successful drilling demonstration in Texas. The company's work builds on PSFC's initial development of millimeter-wave technology, which received early support from the MIT Energy Initiative (MITEI) in 2008. This academic-industry collaboration exemplifies how fundamental research in one energy domain can catalyze innovation in another.

Superhot rock geothermal refers to accessing temperatures approaching 400 degrees Celsius at depths of several kilometers—conditions that would destroy conventional drilling equipment. The millimeter-wave approach promises to be faster and more effective than traditional methods, particularly at the high temperatures and great depths required for this resource. PSFC is now planning a new laboratory facility specifically designed to advance this technology further.

"This initiative will leverage MIT's extensive capabilities in geophysics, geochemistry, millimeter-wave technology, and AI, along with existing infrastructure including power, water, and experimental facilities," said Steve Wukitch, PSFC's interim director and principal research scientist. "The goal is to anchor next-generation geothermal innovation within an integrated academic-industry ecosystem, accelerating both technology maturation, de-risking deployment pathways, and developing the needed workforce."

The planned facility will involve collaboration between PSFC and MIT's Earth Resources Laboratory (ERL), directed by Oliver Jagoutz, the Cecil and Ida Green Professor of Geology. ERL will work with PSFC to test millimeter-wave drilling under representative pressure and temperature conditions using realistic rock samples, ensuring the technology can perform in real-world geological settings.

This research comes at a time of growing interest in next-generation geothermal energy. Earlier in March, MITEI's Spring Symposium focused on "Next-generation geothermal for firm power," examining the current state of the industry, innovative technologies, and future opportunities. During the symposium, Wukitch moderated a panel on drilling advances and described the planned PSFC laboratory facility for millimeter-wave testing. Quaise Energy's Matt Houde presented the company's recent progress and outlined future plans.

The momentum continued with a GeoTech Summit co-hosted by MITEI and the Clean Air Task Force, bringing together member companies, next-generation geothermal startups, and investors to accelerate technology development, project deployment, and deal flow in the sector.

This convergence of fusion and geothermal technologies represents a broader trend in energy innovation, where advances in one field unexpectedly benefit another. As the world seeks reliable, clean baseload power to complement intermittent renewable sources, technologies that can unlock previously inaccessible energy resources become increasingly valuable. MIT's work suggests that the path to widespread geothermal energy may run through the same laboratories that are pushing the boundaries of fusion power, creating a virtuous cycle of innovation that could help decarbonize the energy grid while creating new economic opportunities in regions previously considered unsuitable for geothermal development.