Five kilometres below the granite hills of Redruth, Cornwall, the Earth is very hot.
For centuries, miners came to Cornwall for tin and copper. Now, for the first time in Britain's history, engineers are drilling deep into that same ancient rock to pull out something the modern world desperately needs: clean, continuous electricity — and the lithium that powers electric vehicles.
The United Downs facility, operated by Geothermal Engineering Ltd (GEL), began commercial power generation and lithium production on February 26, 2026, marking two simultaneous firsts for the United Kingdom: its first geothermal electricity plant, and its first commercial-scale geothermal lithium facility.
Here's how it works. Water is pumped down a well more than 5km into hot granite rock, where temperatures exceed 190°C. The superheated water blasts back up a second well, spinning turbines that generate electricity 24 hours a day, 365 days a year — unlike solar or wind, geothermal doesn't stop when the sun sets or the wind drops. Octopus Energy has already signed a 3MW power purchase agreement, enough to power approximately 10,000 homes.
But there's a remarkable bonus. The geothermal brine at United Downs is rich in dissolved lithium — over 340 parts per million of battery-grade lithium carbonate equivalent, among the highest concentrations found anywhere on earth. After spinning the turbines, the water passes through an extraction system that pulls out the lithium before the cooled water is re-injected into the ground.
Initial lithium production is 100 tonnes per year. Plans call for scaling to over 18,000 tonnes annually within the next decade — enough lithium for approximately 250,000 EV batteries a year, potentially making Cornwall a significant domestic source of one of Britain's most critical materials.
This is precisely the kind of win-win-win that clean energy optimists have dreamed of: zero-carbon electricity that runs around the clock, extracting a critical mineral without mining, from a single elegant system.
Two more geothermal plants are already planned for Cornwall. Under the hills, something extraordinary has begun. ⚡
*Sources: Geothermal Engineering Ltd · The Chemical Engineer · Envirotec Magazine · ThinkGeoEnergy · The Guardian*
