Startups Explore Advanced Drilling for Geothermal Energy

Start-up companies are developing innovative drilling technologies to access geothermal energy, a potentially abundant but currently expensive power source.

Traditional geothermal energy relies on accessing naturally occurring hotspots near the Earth's surface. However, advanced drilling techniques could allow for the exploitation of super-hot geothermal resources anywhere in the world. Companies are focusing on overcoming the limitations of conventional drilling, which becomes costly and time-consuming when encountering hard rock at high temperatures.

One such company, Quaise, with origins at the Massachusetts Institute of Technology (MIT), is employing a method called millimetre wave drilling. This technique uses electromagnetic waves, similar to microwaves, to melt and vaporize rock, thereby penetrating the subsurface without the need for physical drill bits. Harry Kelso, Quaise's communications manager, explained that this approach bypasses the wear and tear on equipment associated with conventional drilling.

"Millimetre wave drilling really enables you to access super-hot geothermal just about anywhere in the world," Kelso said. While Quaise's initial projects, such as one planned in Oregon, will incorporate conventional drilling, the millimetre wave technology is key to reaching deeper, hotter rock.

Other firms are also exploring advanced drilling concepts, including the use of projectiles that travel at supersonic speeds. Addressing the resource needs of these next-generation geothermal systems is also critical. While some advanced geothermal methods could pose risks of water contamination or excessive consumption, careful engineering can mitigate these concerns. Quaise's system, for instance, initially requires a significant amount of water, but the water is then continuously circulated and recycled over the hot rocks.

Despite the technological advancements, the economics of next-generation geothermal energy remain a significant hurdle. "The economics are somewhat challenging," Kelso admitted. "Geothermal today is still more expensive because you are not getting as much power out of the well as you would if you were using that well for fossil fuel."

Quaise aims to improve the economic viability by targeting rock temperatures between 300 and 500 degrees Celsius. Kelso noted that higher temperatures allow for significantly more energy extraction per well, which can dramatically alter the power potential and economic feasibility of geothermal energy. The company is currently seeking further funding, with the goal of having its Oregon project operational by 2030.