The UK’s first geothermal power plant generating electricity has gone into operation at United Downs, near Redruth in Cornwall.
Its integration with a production facility extracting lithium carbonate from geothermal fluids, and now seemingly at commercial scale, also marks a UK first.
Announced on 26 February, a switching-on event was held to commemorate the milestone at the site, which has been developed in a collaboration between UK firm Geothermal Engineering Ltd (GEL) and Italian technology provider Exergy International, which has over 500 MW of operational geothermal capacity worldwide.
Power generated from the Cornwall geothermal power plant will be purchased by Octopus Energy under a 3-MW Power Purchase Agreement (PPA), said to be in sufficient quantity to power 10,000 homes.
Investors Kerogen Capital and Thrive Renewables announced in September 2025 that the project had secured support under Allocation Round 5 (AR5), becoming the first geothermal scheme to receive a Contracts for Difference (CfD) award.
The power plant is supplied by a pair of geothermal wells, one of which is the deepest and hottest ever drilled in the UK, with a depth of over 5000 meters, at which level the geothermal fluid reaches temperatures of over 185 °C.
The Organic Rankine Cycle (ORC) power plant supplied by Exergy has a 3 MWe gross capacity and uses a highly efficient Radial Outflow Turbine to produce electricity using the heat of the geothermal fluid. The condensing system is air-cooled, and thus avoids water consumption. It also does not release vapour into the atmosphere and has minimal visual impact and a small footprint.
Dr Ryan Law, CEO of GEL commented: “Geothermal energy and critical minerals extraction are naturally complementary as they share the same subsurface resource. The hot, mineral-rich fluids that generate clean electricity can also be processed to recover strategic materials like lithium carbonate. Therefore, co-locating power and mineral extraction plants maximises investment in the wells, minimises subsurface disruption and accelerates the transition to secure domestic supply in both critical sectors. The United Downs plants prove we can do this in a way that benefits the climate, communities, and the economy.”
GEL said it has started commercial scale production of zero-carbon lithium carbonate.
“From its February 2026 starting point, the GEL facility has the capacity to produce 100 tonnes of lithium carbonate per annum.”
After power generation, the fluid is processed to extract battery-grade lithium carbonate before being reinjected underground in a closed loop. GEL said the water brought to the surface contains over 340 parts per million (ppm) of battery-grade lithium carbonate equivalent (LCE) making it one of the highest concentrations of lithium in the world.
The group said it aims to scale its production to over 18,000 tpa over the next decade, enough for circa 250,000 EV batteries a year, or 65% of the UK’s 2024 Battery Electric Vehicle (BEV) registrations.
