Cornwall's Mine Depths Yield Clean Power Secret

Cornwall's landscape, historically known for mining, is now home to Britain's first deep geothermal power plant, which commenced operations on February 26, 2026. Located near Redruth, the United Downs deep geothermal plant, developed by Geothermal Engineering Ltd (GEL), is designed to power 10,000 homes continuously.

The plant operates by extracting water from an underground reservoir situated over three miles deep. This water, reaching the surface at approximately 190°C, is used to generate steam and drive turbines for electricity. The water is then returned underground to maintain the cycle. This process offers a consistent energy source, unaffected by weather conditions.

Concerns about seismicity, similar to tremors from fracking, have been raised due to drilling and water injection deep underground. Although mini-quakes of magnitudes up to 1.5 were induced during drilling in 2020, experts assure that the UK's stable geology minimizes risks, and no significant seismic activity has been felt since the operation shifted to pumping.

A surprising discovery at the site is the exceptional concentration of lithium in the geothermal water, roughly twice that found in some of Europe's best lithium sources. This makes the plant capable of extracting valuable lithium as a byproduct, a process that occurs at an ideal temperature after the water has been cooled for power generation.

GEL plans additional projects that could meet half of the UK's lithium demand within a decade, contributing to battery production for electric vehicles. Experts estimate the granite beneath Cornwall holds enough untapped energy to supply 10% of Britain's electricity, positioning geothermal power as a key component of the UK's net-zero strategy and a driver for economic growth.