Uplifting News: Superhot Rock Holds the Energy of the Future | Small Wins Matter

This story has been co-published by Reasons to be Cheerful and the Outrider Foundation.

The Newberry Volcano in central Oregon is set among a ravishing landscape of ancient lava flows, lakes and pine forests. Every year droves of tourists come to admire the geological phenomenon, which was formed over 600,000 years ago.

But this region, in the Pacific Northwest, is also on the verge of becoming a major player in the nation’s green energy transition: just under two miles underground here lies a hot new sustainable energy source — powered by the Earth’s heat.

“Superhot rock is everywhere, but in Newberry it is very shallow,” says Pete Lumley, director of communications at Mazama Energy, a startup that has begun developing cutting-edge geothermal projects in Oregon that are harnessing the potent heat.

While geothermal — using natural subterranean heat to produce energy — has been around for decades, recent advances in technology mean that its potential output is skyrocketing while it is becoming ever-more affordable for consumers.

Mazama’s approach involves injecting water at very high pressure into rocks, which in Newberry are located close to the surface relative to comparable drilling projects and whose temperatures range from 300 to 400 degrees Celsius. Under these hotter conditions, the water becomes what’s known as “supercritical” — a state combining the properties of a liquid and a gas — and is then sent through turbines to generate energy. The company says their method, which is possible thanks to cooling systems that allow drills to be used in much hotter temperatures than previously, produces an energy yield that is five to 10 times greater than that of conventional geothermal power plants, all while using 75 percent less water and requiring 80 percent fewer wells to be drilled.

“We are calling this era the geothermal renaissance,” adds Lumley.

In the race towards decarbonization, solar panels and wind turbines often capture the spotlight. Yet geothermal, which can be used for heating as well as electricity generation, could be a powerful, reliable hero of the world’s clean energy transition. According to the International Energy Agency, the global energy authority, with continued technology improvements and reductions in project costs, geothermal could cover as much as 15 percent of the growth in global electricity demand between 2024 and 2050. It estimates worldwide geothermal capacity could reach 800 gigawatts by then, with an output of almost 6,000 terawatt-hours per year, which is the equivalent of the combined electricity demand of the U.S. and India today.

“It is really a breakthrough development happening in the U.S., it is the frontier of geothermal,” says Hannes Hofmann, a professor and geothermal specialist at the Technical University Berlin in Germany.

The U.S. currently leads the world with 3.9 GW of installed geothermal capacity, nearly a quarter of global output.

“They can drill faster than we thought possible, and superhot rock gives a much higher output, making it much more affordable,” adds Hofmann.

Part of the leap forward has also been enabled by the emergence of horizontal drilling, a practice first developed by the shale and gas industry. It allows multiple wells to be used from a single drill site and facilitates access to hard-to-reach areas.

Roland Horne, a professor of energy science and engineering in the Stanford Doerr School of Sustainability, adds that the horizontal well method has proven a “game changer” for geothermal that has allowed “enormous” reductions in cost.

Mazama is using that technology to target higher temperatures. At its pilot site last year, for example, the company reached a 629 degrees Fahrenheit (331 degrees Celsius) temperature in a geothermal well, claiming it to be the world’s hottest geothermal system ever. This year Mazama will complete a further 15 megawatt demonstration on the Newberry site, with ambitious plans to scale. By 2029, Mazama says it will have drilled 18 to 24 wells, with a total 200 megawatt output. It claims the site has a total five gigawatts potential — more than the current total geothermal capacity of the U.S.

“We’ve proven that it works,” says Lumley.

Hofmann nonetheless believes the superhot temperatures will be “harder to manage.”

But Mazama is far from the only player in the geothermal game.

Fervo Energy, a Houston-based company, has projects using horizontal wells that are even farther along the pipeline than those of Mazama, running at slightly lower temperatures. In October, it will open a $462 million project with a capacity of 100 megawatts in Beaver County, Utah, with long-term plans to scale up to two gigawatts — enough to power hundreds of thousands of homes.

“It’s not a demonstration, but a full-scale project,” says Horne.

What’s more, Fervo’s Beaver County project was done with remarkable speed. The site went to power in two and a half years, compared with the five to 10 years required for conventional projects, according to Horne. And the pace is likely to accelerate further: Fervo has drilled 25 wells in the last two years with a single rig — now it has a second.

Yet despite being a trailblazer, the U.S. still only produces 0.4 percent of its energy with geothermal, and that mostly comes from the western states, according to the U.S. Energy Information Administration. Today, for example, about six percent of California’s energy comes from geothermal, and Nevada produces about nine percent.

But the potential is huge: According to preliminary modeling by the Clean Air Task Force, a nonprofit, about 20 percent of the land surface of the U.S. has exploitable superhot rock.

Meanwhile, Horne estimates that geothermal could be deployed for competitive prices in at least half of the 48 states, plus Alaska.

“But you have to find the goldilocks, not too deep, not too hot, not too chemically dangerous,” says Horne, who last year convened more than 450 experts from 28 countries at the 50th Stanford Geothermal Workshop to exchange ideas and report results.

One encouraging sign is that there appears to be bipartisan support for geothermal, which is not always the case with renewables. Mazama’s Newberry site benefited from a $25 million grant from the U.S. Department of Energy. And in February, the department announced a further $171.5 million to support “next-generation geothermal field-scale tests,” stating that the U.S. has the potential for at least 300 gigawatts of “reliable, flexible geothermal power” on the grid by 2050.

“The Trump administration likes geothermal, they are streamlining regulation,” adds Horne.

Across the globe, interest and investment in geothermal is also heating up. Kenya already sources half of its energy from geothermal; Iceland more than two-thirds; New Zealand around a fifth. Meanwhile, in February, the U.K. opened its first geothermal power plant, enough to power 10,000 homes. Hofmann believes that geothermal could realistically account for a quarter of Germany’s heating needs.

Yet the major concern with geothermal has historically been, and continues to be, the risk of so-called “induced seismicity” — human activities causing earthquakes. There have been a number of cases of this happening due to geothermal projects, such as a 2.6 magnitude quake in eastern France in 2020 and a 5.5-magnitude earthquake that struck South Korea in 2017, injuring 90 people and causing $52 million in damage.

But experts say that the risk has been reduced significantly in recent years. “It’s definitely a concern,” says Hofmann. “But because of these cases in the past, a lot of research has been done and methods have been developed to deal with this issue. It usually only happens if an operator continues despite early warnings.”

Hofmann adds that the risk of human harm is much lower in regions where the U.S. is deploying geothermal due to the lower population density.

Mazama points to the fact that in Newberry, seismic activity is constantly monitored and that no induced seismicity has been recorded.

In areas with larger populations and urbanized areas, like along the San Andreas fault in California, it would be more of a risk, says Hofmann. But even then there is “very little” chance of earthquakes in populated regions like the north of Germany due to the minimal seismic activity. “I think it would be the safest place in the world to do this,” he says.

Horne adds that new geothermal projects are being done in a “gentler” way — instead of making one big fracture, making dozens of smaller ones, thereby reducing the risk of earthquakes. He also makes a comparison with lithium ion batteries, which initially caught fire fairly regularly. “Not anymore,” he says. “It’s down to engineering.”

Another particularity with geothermal has both upsides and challenges: the fact that it is constantly on full supply, 24/7, like nuclear.

Experts say that this is good news for reliability, since, unlike solar and wind, it is not dependent on the weather. But it is also posing logistical challenges for the electricity grid, which could struggle with peaks of supply. Lumley says that Mazama is working with power companies in Oregon to help manage the load. However, precisely because constant energy supply is a requirement, geothermal is seen as a great match for the intensive energy needs of data centers.

And amid recent energy supply disruptions, geothermal is becoming even more attractive, with Europe looking to learn from the U.S. In May, Hofmann began work on an EU-funded research project to transfer this model of U.S. geothermal tech to a project in Litoměřice, Czechia. A study in February estimated that geothermal could replace 42 percent of the EU’s coal and gas-fired generation.

“When we demonstrate that this works, we are confident there will be upscaling across Europe,” he says.