On 26 February 2026, after nearly two decades of work and a total investment of £50 million, the United Downs site near Redruth in Cornwall became the UK's first operational deep geothermal power plant. Developed by Geothermal Engineering Ltd (GEL), it required drilling the deepest onshore well in British history — more than five kilometres straight down through granite — to reach water superheated to over 190°C by the earth itself.
That water now drives turbines generating enough electricity for 10,000 homes, sold to Octopus Energy in London and distributed via the national grid. Unlike wind and solar, geothermal energy is entirely weather-independent, providing constant, round-the-clock power — something that makes it a potentially valuable stabiliser for Britain's renewable energy mix.
An unexpected discovery gave the project a second dimension entirely: the deep brine is rich in lithium, one of the critical minerals needed for electric vehicle batteries. GEL says the site will produce 100 tonnes of lithium carbonate annually — enough for 2,500 car batteries — marking the first domestically produced supply of its kind in the UK.
Ryan Law, the company's chief executive and founder based in Cornwall, described the launch as the result of nearly 20 years of persistence. Two more Cornwall sites are in development, and the British Geological Survey estimates that the UK's total geothermal potential could exceed 200 gigawatts — enough to make a meaningful contribution to the country's energy future.