UK’s First Geothermal Power Plant Switches On in Cornwall

The UK’s first geothermal power plant has begun generating electricity, bringing deep geothermal power onto the national grid for the first time.

Located at the United Downs Industrial Site near Redruth in Cornwall, the flagship project developed by Geothermal Engineering Ltd (GEL) taps heat from granite rock formations more than five kilometres beneath the surface. The site is home to the UK’s hottest and deepest onshore well, drilled to more than 5,000 metres.

The project has secured a long-term agreement with Octopus Energy, which will purchase up to 3 megawatts of electricity — enough to power up to 10,000 homes. The deal provides early commercial backing for a technology long discussed but never before deployed at power-generating scale in the UK.

Unlike wind or solar, geothermal provides constant baseload electricity. GEL says the plant produces power with a carbon footprint of just 5–15g of CO₂ per kilowatt-hour while using a relatively small land footprint for around 5MW of output.

The development has been supported by a mix of public and private investment, alongside government backing that guarantees a stable price for the electricity it produces — helping bring a first-of-its-kind geothermal project to commercial operation in the UK.

Beyond electricity, surplus heat from the site could support local industry, agriculture or district heating networks. The geothermal fluid also contains significant lithium concentrations, opening the door to potential future extraction and strengthening links between Cornwall’s renewable energy resources and the UK’s growing battery supply chain.

With power now flowing to the grid, the project positions geothermal as a new — and potentially scalable — pillar of the UK’s clean energy mix.