Earth's heat used to generate electricity for UK homes in first geothermal project

A deep geothermal project at the United Downs site has produced electricity that will be sold to Octopus Energy to meet the needs of up to 10,000 homes, and the British Geological Survey called it a major step forward; high drilling costs could make repeating the work difficult.

A deep geothermal project at the United Downs site has produced electricity for the UK grid for the first time. The scheme drilled down to depths where rock temperatures approach 200C and used fractures in granite to circulate water and extract heat. Geothermal energy uses heat from below ground as a continuous source for power and heat, distinct from intermittent sources such as wind and solar. The project has cost about £50m so far and was funded by private investors and the EU. Key facts: - The project reached deep boreholes where temperatures are reported as nearly 200C, which is sufficient to generate electricity. - Dr Monaghan, head of geothermal at the British Geological Survey, explained that fractures in granite are used to circulate water that picks up heat for electricity production. - The British Geological Survey described the outcome as a "major step forward" for geothermal in the UK. - The scheme has cost about £50m to date and received funding from private investors and the EU. - Ryan Law, CEO of GEL, was reported as saying he was "tremendously excited" after 15 years of work, and the power produced has been sold to Octopus Energy to be delivered via the national grid to meet electricity needs for up to 10,000 homes. Summary: The project has put always-on geothermal electricity into the national grid and is reported to supply power that could meet the needs of up to 10,000 homes, while observers note high drilling costs that may limit replication. Undetermined at this time.