Is geothermal energy on the cusp of a worldwide renaissance?

The UK’s power grid has started to get its first geothermal power amid a surge in global interest in geothermal, thanks to improving well technologies and growing demand for data center power. The United Downs plant in Cornwall will produce 3 megawatts of electricity while also producing lithium for battery production.

“Let’s call it a renaissance,” says Ryan Law, CEO of Geothermal Engineering Ltd., the company behind United Downs. “There’s a lot going on in the United States. There’s also a lot going on in Europe, I think, in part because of our insatiable demand for 24/7 renewable energy.”

As energy grids now rely on wind and solar generation that scales with weather conditions, geothermal energy can provide clean, continuous energy with a shorter construction time than a nuclear power plant and a lower environmental impact than hydropower.

Although geothermal energy heated Roman baths 2,000 years ago and produced electricity for decades in volcanic areas like Iceland and Kenya, it currently meets less than 1% of global energy demand.

That could change soon. The International Energy Agency estimates that geothermal could meet 15% of projected growth in electricity demand by 2050, producing more electricity than the United States and India consume today.

The United Downs facility encapsulated the ups and downs of the industry. Tin and copper miners have long struggled with water flowing through faults in the hot granite downstream from Cornwall, and a test well was drilled in the area during a brief burst of geothermal exploration during the oil crisis of the 1970s and 1980s. Law, a geologist, launched the project in 2009 but struggled to raise funds.

“It’s like oil and gas risk with a utility [electricity sale] back, and so it wasn’t that popular,” he says.

United Downs eventually secured £20m in grants, mainly from the European Union, and drilled two wells in 2018 and 2019 to depths of 2,393 meters and 5,275 metres, deeper than most projects at the time. There, radioactive decay of isotopes of uranium, thorium and potassium heats water to 190°C (374°F) under high pressure. A pump in the deepest well pulls water to the surface, where it produces steam to turn a turbine and generate electricity.

Law then rediscovered something the miners had noticed: the water coming out was rich in lithium, an essential element for electric vehicle batteries. This will be removed by plastic beads coated with chemicals, rinsed with fresh water and injected with CO2 to produce 100 tonnes of lithium carbonate powder per year initially, with the aim of eventually reaching 2,000 tonnes. The geothermal fluid will then flow to the shallower well and through faults in the rock to the deeper well, thereby maintaining pressure in the reservoir.

Thanks in part to lithium, which could bring in 10 times more revenue than electricity, United Downs was able to raise £30m of private equity investment.

“Adding minerals suddenly started making this area very attractive,” says Law, who has permits for two 5-megawatt plants.

The outlook is brighter in EU countries like Hungary, Poland and France than in the UK. They have hot water closer to the surface and could develop 43 billion watts of geothermal energy for less than 100 euros per megawatt hour, like coal and gas, according to think tank Ember.

“We still face power grids dominated by wind, solar, hydro and batteries,” says Frankie Mayo of Ember. “But that doesn’t mean that predictable low-carbon production doesn’t have a really valuable role.”

And geothermal is now becoming economical beyond shallow hot spots thanks to oil and gas fracking techniques. Fervo Energy, a spinoff from Stanford University in California, is building a 115-megawatt geothermal plant to power Google’s data centers in Nevada and has reduced the time to drill a well from 60 days to 20 days with diamond bits.

She also drilled horizontal wells and pumped water at high pressure to crack the rock between them. This creates dozens of hot fractures through which water can flow, rather than just a few in a vertical well project like United Downs.

This “enhanced geothermal” is expected to cost less than $80 per megawatt hour by 2027, making it viable in most of the United States, according to a study by Roland Horne of Stanford University and colleagues. President Donald Trump’s administration has retained a geothermal tax credit implemented under the previous administration.

In the United States, geothermal energy could produce at least 90 billion watts by mid-century, or about 7% of current capacity, according to the Department of Energy.

“Your costs are a little bit higher if you do hydraulic fracturing,” Horne says. “But if you get three to four times more energy out of it, that improves profitability and makes it competitive with solar, wind and gas on average.”

In Germany, an upgraded geothermal power plant had to temporarily close after causing a 2.7 magnitude earthquake in 2009, and concerns were also raised about possible water contamination. But Horne says these problems can be avoided. And as improved geothermal facilities are built — at least a half-dozen projects larger than 20 megawatts are underway in the United States — communities and lenders will likely become more comfortable, estimates Ben King of the Rhodium Group think tank.

“I wouldn’t expect this to happen everywhere, but it can certainly play an increasing role on the grid,” King says, “especially as we look to 2050, if we have double, triple the amount of electricity that we need, because we have all these new things that we’re plugging in.”