Raphael Thys
A new drilling technology able to reach depths of 20 km could enable geothermal power to be accessed almost anywhere in the world.
Quaise Energy, founded in 2018 and based in Cambridge, Massachusetts, is a company aiming to revolutionise geothermal power by using beams of light to vaporise rock. Instead of traditional methods of drilling down, new contactless drills would bore holes as deep as 20 km (12.4 mi) into the Earth's crust. In these ultra-deep environments, rock reaches temperatures upwards of 500°C (932°F). Water could then be injected downwards and converted to supercritical steam, shooting back up to the surface and driving turbines to produce electricity.
A major advantage of this technology is that it could be used almost anywhere on Earth. Until now, geothermal energy has been limited to specific regions with hot springs or areas near tectonic plate boundaries. Iceland, for example, is a major hotspot and more than a quarter of its electricity is produced from geothermal sources, while 85% of all houses in the country are heated with geothermal energy. The United States has exploited geothermal energy since 1960 and is the world's largest producer, with 3.7 GW of electrical capacity or about 30% of the global total. However, only 26 of the world's 195 nations currently use energy from geothermal sources. While capacity has tripled since 1990, it still accounts for just 0.3% of total electricity generation.
By contrast, the new technique being developed by Quaise could potentially give 95% of the world's population access to clean geothermal energy. Since it requires less than 1% of the land and materials of other renewables, geothermal could solve many global environmental problems, not just climate change. Furthermore, it has the advantage of running consistently – 24 hours a day, 7 days a week – unlike the intermittent nature of solar and wind. Quaise has estimated that its technology could enable terawatt-scale geothermal power in the future, two orders of magnitude greater than today. Yet another benefit is that the skills, knowledge, and equipment needed for geothermal are somewhat similar to those of oil and gas (the largest workforce in energy today), so that professionals in the fossil fuel industry can easily transfer into a clean energy role.
Aside from vastly expanding the geographic coverage of this energy source, the sheer feat of engineering involved deserves a mention. Until now, the deepest artificial point on Earth has been the Kola Superdeep Borehole in Russia. As shown in this excellent visualisation by Metal Ball Studios, that Soviet-era project reached 12,262 metres (40,230 ft) below ground. Quaise would smash that record if achieving the full potential of 20,000 metres (65,600 ft).
This month, Quaise announced that it has secured $40 million in Series A financing led by U.S. venture capital firm Safar Partners, with participation from several other investors. The funding will be used to build field-deployable drilling machines to demonstrate the capabilities of this novel technology. It will also expand the company's multi-disciplinary teams based in Boston, Houston, and Cambridge, UK, doubling its number of engineers and creating new roles to plan and execute its commercialisation strategy.
"A rapid transition to clean energy is one of the biggest challenges faced by humanity," said Arunas Chesonis, the Managing Partner of Safar Partners. "Geothermal energy can provide a lot more power using fewer resources. We have to approach the clean energy transition from both of those angles. Quaise's solution makes us optimistic for a future where clean, renewable energy will secure the future of our planet."
Paul Woskov, a Senior Research Engineer at MIT and co-founder of Quaise, spent a decade working to prove the physics involved. Essentially, the system will use a beam of millimetre-wave energy – an electromagnetic frequency in the microwave range – generated by a gyrotron on the surface. The beam will shoot down the drill hole alongside a gas (likely nitrogen or argon), evaporating layers of rock. The gas will bind with particles of rock and be carried back up to the surface.
If all goes well, the first hybrid platform (combining conventional rotary and millimetre wave drilling) will be demonstrated in 2024. Quaise then plans to deploy its first "Super Hot Enhanced Geothermal Systems" by 2026, rated to 100 MW of thermal energy from a handful of wells. Another milestone is scheduled for 2028 when the company intends to retrofit an old fossil fuel power plant with its new, clean, geothermal system. By repurposing traditional power plants, Quaise will save infrastructure costs and believes it can utilise the current oil and gas industry's workforce to accelerate the shift towards a sustainable energy industry.
"We need a massive amount of carbon-free energy in the coming decades," said Mark Cupta, Managing Director at Prelude Ventures, one of the partners in this funding round. "Quaise Energy offers one of the most resource-efficient and nearly infinitely scalable solutions to power our planet. It is the perfect complement to our current renewable solutions, allowing us to reach baseload sustainable power in a not-so-distant future."
"The ubiquity and constancy of deep geothermal energy is tantalising but economically inaccessible with conventional drilling technologies," said Allison Hinckley, Senior Associate at Fine Structure Ventures. "Quaise's radically different drilling technology offers a path to access this resource at a global scale with commensurate reductions in carbon emissions."
"This funding round brings us closer to providing clean, renewable baseload energy," said Carlos Araque, CEO and co-founder of Quaise. "Our technology allows us to access energy anywhere in the world, at a scale far greater than wind and solar, enabling future generations to thrive in a world powered with abundant clean energy."