Britain’s first deep geothermal power plant is set to begin operations this week, marking a significant milestone in the country’s push for reliable renewable energy and domestic critical mineral production.
Located near Truro in Cornwall, the facility will generate round-the-clock electricity using superheated water drawn from deep beneath the Earth’s surface, enough to power around 10,000 homes.
The project, developed by Geothermal Engineering Ltd (GEL), has taken nearly 20 years of planning, drilling and investment to reach completion. Engineers sank the deepest onshore well ever drilled in the UK to access granite rock formations that naturally store and conduct underground heat.
By circulating water through fractures in these hot rocks, the plant captures temperatures approaching 200°C. The heated water then drives turbines to generate electricity before being reinjected underground, creating a closed-loop system with minimal emissions.
Experts say the achievement could open a new chapter in Britain’s energy mix. Unlike wind or solar farms, geothermal energy operates continuously, unaffected by weather or daylight. That makes it particularly valuable for stabilising the national grid.
Drilling, however, has been the biggest challenge. According to the British Geological Survey, deep geothermal projects require significant upfront investment and technical precision, which has historically discouraged widespread adoption.
“This is a major step forward for the UK,” said Dr Charlotte Monaghan, the survey’s head of geothermal. “We have enormous heat resources underground, but unlocking them safely and affordably is complex.”
The Cornwall site has cost roughly £50 million, funded through private investors and European development funds secured before Britain left the European Union. GEL chief executive Ryan Law described the moment as the culmination of “15 years of hard graft and setbacks”.
Beyond electricity, the plant also offers a second strategic benefit: lithium extraction. The hot brine pumped from underground contains dissolved lithium carbonate, a critical component used in electric vehicle and battery storage technologies.
GEL plans to recover around 100 tonnes of lithium annually at first — enough to supply batteries for about 1,400 electric vehicles — with ambitions to scale production to 18,000 tonnes in the future. That would significantly reduce Britain’s reliance on imports, particularly from Asia.
Currently, China processes more than 60 percent of the world’s lithium, dominating global supply chains for batteries. Domestic extraction could strengthen the UK’s energy security and support its growing electric vehicle industry.
Electricity from the site has already been contracted to Octopus Energy, which will distribute the power through the national grid. The company described the project as “a genuine game-changer” that provides “always-on green energy”.
Industry advocates argue geothermal could play a broader role nationwide. Deep heat resources exist not only in Cornwall but also in parts of Scotland and northeast England, though no other large-scale power projects are yet approved.
Shallow geothermal systems are already more common. Around 30,000 UK homes use ground-source heat pumps, while some councils tap heat from flooded mine workings to warm buildings. These smaller systems cost less but cannot produce electricity at scale.
Globally, interest in deep geothermal is rising. The International Energy Agency reports investment has grown sharply in recent years, driven by demand from industries requiring steady power.
Major technology companies such as Google, Meta and Microsoft are increasingly exploring geothermal solutions to power energy-hungry data centres while lowering carbon footprints.
For the UK government, the Cornwall project aligns with wider net-zero targets and efforts to diversify renewable sources. Ministers recently appointed a dedicated geothermal lead, signalling growing political support for the sector.
Still, scaling up will depend on reducing drilling costs and offering stable policy incentives. Industry leaders warn that without government backing, similar projects may struggle to attract financing.
For now, though, the Cornwall plant stands as proof that deep geothermal energy can work in Britain. As turbines begin to spin, the country taps into a resource that has been quietly waiting beneath its feet for millions of years — constant, clean and home-grown.
