Geothermal startup Quaise raises $40M for ultra-deep drilling

The MIT spinoff wants to unleash the vast geothermal resources today’s technologies can’t reach.
By Maria Gallucci

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Geothermal energy startup Quaise Energy uses a gyrotron to generate millimeter waves that melt and vaporize holes into hard rock. (Quaise Energy)

Most geothermal energy wells reach down thousands of feet into rocks or reservoirs, tapping heat deep within the earth to make steam and produce clean electricity. Yet were developers to drill deeper, say 30,000 feet or farther, they could access a much more abundant and constant heat supply — not just near hot springs or volcanoes but virtually anywhere on land. The trouble is that today’s drilling methods aren’t up to the task.

Quaise Energy, a geothermal startup with MIT origins, says it has found a way to unleash the earth’s hardest-to-reach heat resources: by drilling down using high-frequency beams to melt and vaporize rocks. Now, the company will have a shot at deploying its technology in the field.

On Tuesday, Quaise closed a $40 million Series A financing round led by Safar Partners and including Prelude Ventures, The Engine and other investors. The funding will allow the startup to double its engineering team to 40 people and begin scaling its advanced drilling system from laboratory experiments to real-world demonstrations.

The idea is to provide geothermal power no matter where you are in the world,” said Carlos Araque, CEO and co-founder of Quaise, which is based in Cambridge, Massachusetts. 

The energy transition is a terawatt-sized challenge, so we are developing and unlocking geothermal at that scale,” he told Canary Media.

The investment is one of the largest raises to date among geothermal energy startups working to extract energy from deeper wells and hotter sources. With this new round, Quaise has raised a total of $63 million for its rock-vaporizing method, including a $5 million grant awarded by the U.S. Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E).

Quaise is in this group of new drilling concepts that take traditional oil-and-gas mechanical drilling methods and turn it on their head,” said Jamie Beard, executive director of the Geothermal Entrepreneurship Organization at the University of Texas at Austin. The goal is faster [and] hotter,” she added. Where current drill bits fail, they succeed.”

Quaise Energy prepares to blast a sample of basalt, one of the hardest rocks in the world, with millimeter waves. (Quaise Energy)
Millimeter waves melted and vaporized a 2-inch-deep hole in a slab of basalt rock. (Quaise Energy)

The $40 million raise reflects both the rising interest among investors and energy companies in tapping super-hot geothermal resources — and the hefty expense and long timeline needed to develop such transformative technologies, she said.

Quaise is trying something entirely new to see if they can get it to work and be economical,” Beard said. And that’s really interesting and cool. But it’s going to take a minute to adapt the technology to drill rigs.”

Quaise’s millimeter waves could drill into the ground this year

Geothermal energy can provide 24/7 baseload clean electricity to the grid, yet it accounts for only about 0.4 percent of annual U.S. electricity generation. Geography is largely to blame: Few places have hot springs, geysers or rocks hot enough at depths shallow enough for drilling to be technically or financially feasible. Most geothermal projects don’t reach deeper than 10,000 feet.

However, starting around 33,000 feet below the surface, geothermal resources can be found almost anywhere in the country, the U.S. Department of Energy said in its 2019 GeoVision report. Drilling to such depths will require equipment that can handle extreme temperatures — think 700 degrees Fahrenheit — along with the high pressures and intense chemical conditions that are found many miles beneath our feet.

Quaise’s approach to geothermal drilling involves burning holes into rocks by blasting them with high-frequency electromagnetic waves called millimeter waves.” The beams are produced with a gyrotron, a high-powered vacuum tube that’s also used to conduct nuclear fusion experiments.

Paul Woskov, a senior research engineer at MIT’s Plasma Science and Fusion Center, developed this method over a decade ago. At the center in Cambridge, researchers used a 10-kilowatt gyrotron in a test chamber to bore small holes into slabs of granite, basalt, sandstone and limestone.

In 2018, Araque and his co-founders formed Quaise to further develop and commercialize Woskov’s technology. The startup was initially majority-owned by AltaRock Energy, a leading geothermal energy developer, though today Quaise is its own entity. In 2019, AltaRock won an ARPA-E grant that allowed researchers working on the project to move out of MIT’s facilities and into the Oak Ridge National Laboratory in Tennessee and scale their experiments. (I covered the ARPA-E announcement for IEEE Spectrum.)

A gyrotron at Oak Ridge National Laboratory in Tennessee. A gyrotron can generate millimeter waves at power densities higher than the surface of the sun. (Quaise Energy)

The earlier experiments at MIT produced 10-centimeter-deep holes in palm-sized slabs of rock. At Oak Ridge, Quaise has vaporized 3-foot-deep holes into larger rocks using the national lab’s more powerful megawatt-size gyrotrons. This year, the startup is planning to drill about 30 feet into the actual ground outside the Oak Ridge facility.

Araque said the $40 million investment will enable Quaise to try its technology in the real world within a couple of years. The company is planning to drill a 330-foot well in New Mexico or Colorado with the oil-and-gas drilling contractor Nabors Industries, which invested $12 million in the startup last year.

After that, Quaise could drill a 3,300-foot-deep hole near the Newberry Volcano in Bend, Oregon. AltaRock, which is studying the crater, has called the site probably the biggest untapped geothermal resource in North America.” Geologists believe a shallow magma body sits only 6,500 to 16,500 feet below the surface. Drilling here would allow Quaise to validate its technology in supremely hot conditions without having to dig too far down to start, Araque said.

Drilling deeper carries risks — and potentially massive rewards

Accessing extreme depths comes with plenty of challenges, beyond just developing sturdier tools. The deeper Quaise’s millimeter waves go, the more energy the system will need to consume to power the gyrotrons. Right now, that means drawing from the electric grid or running diesel generators — though Araque estimated the amount of fossil fuels potentially consumed in drilling would amount to less than 1 percent of the clean electricity delivered over the well’s lifetime.

Among the biggest risks for any advanced drilling system is seismic activity. In recent years, geothermal projects using different types of technologies were shut down in Switzerland, South Korea and France after triggering earthquakes and rattling surrounding cities.

Beard, of the Geothermal Entrepreneurship Organization in Texas, said more technology development is needed to figure out which conditions are more likely to cause seismicity. She said there’s disagreement among experts about whether drilling to unprecedented depths of, say, 60,000 feet carries more or less risk of inducing tremors.

We need to have much more standardization in terms of how projects are developed,” she said, noting that the geothermal industry could follow the oil and gas industry’s lead when it comes to sharing geological and drill performance data as technologies scale.

If Quaise succeeds in demonstrating its novel approach, the startup plans to drill ultra-deep wells not just on the sides of volcanoes but primarily alongside existing power plants, Araque said.

Instead of coal or natural gas, steam produced with the earth’s heat could drive turbines and generate electricity using existing infrastructure. Power plants tend to be built near population centers, reducing the need for the long transmission lines that connect remote wind and solar farms. And existing plants tend to sit atop private property, which could potentially help Quaise avoid legal challenges like those facing geothermal projects on public land.

We’re talking about hundreds of gigawatts converted [to geothermal] in the space of a decade,” Araque said of his company’s ambitions.

Arunas Chesonis, managing partner of Safar Partners, which led the $40 million investment, said geothermal energy could help accelerate a rapid transition away from fossil fuels and do it using fewer resources than other clean energy technologies. We have to approach the clean energy transition from both of those angles,” he said in a statement. Quaise’s solution makes us optimistic for a future where clean, renewable energy will secure the future of our planet.” 

Maria Gallucci is a senior reporter at Canary Media. She covers emerging clean energy technologies and efforts to electrify transportation and decarbonize heavy industry.