At the beginning of 2021 the UK’s first geothermal electricity power purchase agreement was signed. The United Downs Deep Geothermal plant in Cornwall has agreed to provide Ecotricity with reliable and constant electricity generated from the heat beneath our feet.
You might be familiar with geothermal electricity. It’s been around in places like Larderello Italy since the early 1900s and is popular worldwide in locations close to plate boundaries where geothermal energy is rife and accessible. In 2019 (most recent data) there was around 14 Gigawatts of capacity worldwide. Geothermal energy is almost unique in the realm of renewables because it is so reliable and constant.
I will not go into detail on the technology used at United Downs, but it is relevant to mention that it is different to the classical approach used in places like Italy and Iceland. It is called enhanced geothermal or hot dry rocks (HDR) and a good overview can be found here.
But what does United Downs tell us about UK renewables policy? It’s a story of industrial strategy, European cooperation, and promising opportunity…
Way back in 1990 there was speculation that HDR could be an attractive source of power in the UK, but also scepticism about it ever being economically viable. The technology wasn’t mature, but the interest and the opportunity was there. In 1992, the Department of Energy (now BEIS) invested £3.3 million into HDR research. The objective was “to improve the understanding of HDR technology in a collaborative European programme”.
Development was slow, growing out of earlier research by the Camborne School of Mines. By 2012, private investors were sniffing at the idea alongside funding from the local council and the ERDF.
Fast forward to this year, and profitable UK geothermal power is now a reality. United Downs is online already, with drilling underway for another CHP plant at The Eden Project as well as an operational, (albeit small) geothermally-heated section of Jubilee Pool in Penzance.
We can learn lessons from this success. Judicious investment in new technologies is always worth the risk. The progress from these early commercial ventures gives UK companies industrial experience which is unique and very valuable in countries such as the USA and Japan who will pay for that expertise when they come to exploiting their own resources. One hopes that the UK cutting ties with the EU won’t make the sharing of ideas and funding across borders more difficult in the future.
Looking ahead to the 2050 net zero goal, the story of United Downs is an encouraging narrative of scepticism leading to optimism, backed by government funding, precipitating the slow and successful development of a new, exciting, and exportable energy sector.
Future Energy Press 
