UK’s first deep geothermal project for 36 years opens at Eden Project

The first new deep geothermal heating plant in the UK since 1987 has opened today at the Eden Project in Cornwall, with its developers hopeful the scheme will help to inspire a new wave of geothermal energy projects across the country.

Geothermal energy, which involves extracting the heat from deep underground and using it for heating and to generate electricity, currently delivers less than 0.3 per cent of the UK’s annual heat demand.

Eden’s new geothermal well, which stretches almost 5 kilometres beneath Earth’s surface, is now pumping heat into the tourist site’s famous geodesic “biomes” and a new greenhouse, developers said on 19 June.

The project has taken more than a decade to deliver, with Brexit, covid-19 and supply chain issues all causing delays. A series of seismic tremors also halted testing on the new well in March 2022.

Gus Grand, the CEO of Eden Geothermal, the company behind the project, says it is “fantastic” to have it completed.

The well is expected to reduce the Eden Project’s heating bills – which total more than £1 million a year – by 40 per cent and allow the site to offer a menu supplied with food grown on site all year round.

Eden Geothermal hopes its new well will inspire large institutional or industrial sites, such as hospitals and factories, to pursue geothermal. Grand says she is already fielding calls from large food producers interested in visiting the well to learn more.

The UK is well suited for geothermal energy, she believes, in part because its resources are already well mapped. “We have very, very good exploration data in the sedimentary aquifers because of oil and gas exploration,” says Grand. But the UK lags well behind its European neighbours in installation rates.

Studies have suggested geothermal could meet the UK’s annual heating demand for at least a century, prompting MPs last year to call on the government to do more to bring new projects to fruition.

A government white paper on geothermal energy’s potential is expected in the coming weeks. Grand hopes this will tackle some of the major policy barriers to its development, such as the lack of ring-fenced subsidies.

Delays in connecting new renewable energy projects to the electricity network are another major issue. Adding these new connection points requires upgrades to the network and to local electricity substations. These upgrades haven’t kept pace with the boom in renewables over the past decade – particularly in the south-west – leaving the system logjammed.

The Eden Project could host an additional well, which would allow the generation of clean electricity alongside heat. But the earliest grid connection the company has been offered for the project is December 2036. “It’s really, really hard for me to build a business case” based on such a distant date, says Grand.