Geothermal Power Plant at United Downs, Cornwall, UK
Thomas Frost Photography/Geothermal Engineering Limited
The United Kingdom is making strides in renewable energy with the introduction of its first geothermal power generation. This initiative comes at a time when global interest in geothermal energy is surging, driven by advancements in drilling technology and the rising electricity demands from data centers. Located in Cornwall, the United Downs facility is set to generate 3 megawatts of clean energy while also producing lithium for battery manufacturing.
“We’re witnessing a renaissance,” says Ryan Low, CEO of Geothermal Engineering Ltd., the company behind the United Downs project. “There is substantial activity in the United States and Europe, largely fueled by an ever-growing demand for reliable renewable energy.”
As traditional energy grids increasingly rely on weather-dependent sources like wind and solar, geothermal power stands out by offering continuous clean electricity, shorter construction timelines compared to nuclear plants, and a lesser environmental footprint than hydropower.
Geothermal energy has historical significance, heating Roman baths over 2,000 years ago, and has been harnessed for electricity in volcanic regions like Iceland and Kenya for decades. However, it currently accounts for less than 1% of the global energy supply.
Fortunately, the International Energy Agency (IEA) predicts that geothermal power could satisfy up to 15% of the anticipated increase in electricity demand by 2050, potentially generating more electricity than the combined current consumption of the United States and India.
The United Downs facility represents the evolving landscape of the geothermal industry, facing its share of challenges and successes. Historical mining activities in Cornwall, particularly for tin and copper, encountered issues with water infiltrating faults in the region’s hot granite. The area underwent exploratory drilling during the oil crises of the 1970s and 1980s, but progress stalled.
Low, a geologist, initiated the United Downs project in 2009 and faced significant hurdles in securing funding. “Investing in utilities can resemble oil and gas risks,” he reflects. Despite the challenges, United Downs eventually secured a £20 million grant, mainly from the European Union, and drilled two substantial wells in 2018 and 2019, reaching depths of 2,393 meters and 5,275 meters—deeper than most contemporary projects.
At these depths, the decay of uranium, thorium, and potassium isotopes heats water to 190°C (374°F) under high pressure. Pumps bring this heated water to the surface, creating steam that drives turbines for electricity generation. Furthermore, Lowe discovered the spring water was rich in lithium, a critical component for electric vehicle batteries. Lithium extraction involves a unique process using chemically coated plastic beads, fresh water, and CO2, aiming to produce 100 tonnes of lithium carbonate annually, with plans to scale up to 2,000 tonnes.
The system is designed to maintain pressure within the geothermal reservoir, as the geothermal fluid cycles through the wellbore.
The United Downs project has also attracted £30 million in private equity investment, largely due to the lithium extraction component, which holds the potential to yield returns ten times greater than electricity generation alone. “The addition of mineral extraction has significantly enhanced the project’s appeal,” notes Loh, who holds permits for two 5-megawatt power plants.
European nations such as Hungary, Poland, and France are well-positioned for geothermal development due to accessible hot water sources near the surface. According to think tank Ember, generating 43 billion watts of geothermal energy can be achieved at costs below 100 euros per megawatt hour, comparable to coal and gas.
“Our energy grid remains largely dependent on wind, solar, hydro, and batteries,” says Frankie Mayo from Ember. “However, there is a valuable role for consistent, low-carbon energy generation.”
With advancements in oil and gas fracking technology, geothermal energy is becoming more economically viable beyond just shallow hotspots. Companies like Fervo Energy, a Stanford University spin-off, are pioneering a 115-megawatt geothermal plant to power a Google data center in Nevada, reducing the drilling time for wells from 60 days to just 20.
They employ horizontal drilling techniques and high-pressure water pumps to fracture rock between wells. This method enhances water flow through geothermal reservoirs compared to traditional vertical well settings.
Research predicts that costs for this enhanced geothermal energy could drop to below $80 per megawatt hour by 2027, making it feasible across most U.S. regions. Roland Horne from Stanford University confirms that the administration’s continued support for geothermal tax credits will benefit the industry.
As geothermal power could generate at least 90 billion watts by mid-century—around 7% of the current generation capacity in the U.S., according to the Department of Energy—its potential continues to grow.
“While the cost of hydraulic fracturing is slightly higher,” Horn explains, “the ability to extract three to four times more energy improves overall economics, making geothermal a competitive alternative alongside solar, wind, and gas.”
Concerns are raised regarding potential seismic risks, as German geothermal plants have faced shutdowns after triggering minor earthquakes, alongside fears of water contamination. However, experts like Horne assert that such issues can be effectively managed, and the growing number of geothermal projects—over six underway in the U.S., each promising at least 20 megawatts—will enhance community confidence and attract financial support, says Ben King of the Rhodium Group think tank.
“While geothermal energy may not be applicable everywhere, it certainly holds the potential for a more prominent role in our energy grid as we approach 2050, especially in the face of increasing energy demands,” King concluded.
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Source: www.newscientist.com
