Often overshadowed by other renewables like solar and wind, geothermal energy is “having a moment” in the United States, thanks to the adoption of drilling technologies from the oil and gas industry.
“If we had to invent this stuff ourselves it would have taken years or decades,” Tim Latimer, co-founder of geothermal company Fervo Energy, told the New York Times. “Our big insight was that people in geothermal simply weren’t talking enough to people in oil and gas.”
Traditionally, geothermal plants harness energy by drilling down to natural underground hot water reservoirs. These power sources can sustain round-the-clock energy use, but as there are only a few sites with exactly the right conditions, practical use has been limited to only 0.4% of America’s power.
Now, companies with new technologies are looking to tap into power from a more ubiquitous geothermal source—hot ,dry rocks, which may be hard to reach but are found almost everywhere. With the drilling technologies honed by oil and gas companies in the last few decades, engineers think it’s becoming more feasible to reach that resource. The potential is enormous, writes the Times, citing U.S. Energy Department estimates that there is “enough energy in those rocks to power the entire country five times over.”
Geothermal companies are looking at various ways to tap into that energy. Latimer’s Fervo is using hydraulic fracturing techniques that have drawn the ire of many communities adjacent to oil and gas operations, while Canadian start-up Eavor is building large underground radiators with methods from Alberta’s oil sands.
The new push is driven by the falling cost of the technologies, thanks to techniques being perfected by oil and gas companies.
“Everyone knows about cost declines for wind and solar,” said Cindy Taff, who worked at Shell for 36 years before joining Sage Geosystems, a geothermal start-up in Houston. “But we also saw steep cost declines for oil and gas drilling during the shale revolution. If we can bring that to geothermal, the growth could be huge.”
Other companies are exploring yet-to-be developed tech that could go even farther underground to exploit nearly-limitless heat energy.
“There are huge engineering challenges,” said Carlos Araque, CEO of Quaise, a Massachusetts-based geothermal start-up. “But imagine if you could drill down next to a coal plant and get steam that’s hot enough to power that plant’s turbines. Replacing coal at thousands of coal plants around the world. That’s the level of geothermal we’re trying to unlock.”
There are still challenges to be overcome, and investors remain wary of an energy source that has yet to be proven at scale. There are also permitting issues and a general lack of government support in comparison to fossil fuels, not to mention the dangers of drilling. Those risks include the possibility of triggering earthquakes, though the drilling team at Utah FORGE has been monitoring for such issues—and hasn’t encountered any.
Still, there is a lot of pressure to overcome the challenges as the push for a shift off fossil fuels becomes critical. As Times reporter David Gelles writes in a separate post, “the urgent need to find new sources of clean energy combined with the advances in drilling are creating a moment for geothermal.”
My favorite operator in this space is Alberta company Eavor (https://www.eavor.com/), which is employing not only directional drilling, but a loop that should provide abundant thermal energy without needing parasitic pumping.