Cornwall's Eden Project has launched the UK's first operating deep geothermal heating plant since 1986.
The visitor attraction near St Austell will heat its biomes and nursery using the new 4km geothermal system. The process of drilling deep into the granite at the site was completed in 2021 and Eden Geothermal has now finished the heat main and plant.
The well has a vertical depth of 4,871 metres. The measured depth is 5,277 metres, making it the longest well under UK soil. The geothermal heat system is a single well coaxial system. A 4000m vacuum insulated tube has been inserted into the well, lifting hot water from deep below. This is passed through a heat exchanger and the cooled water is then re-injected into the well via the outer ring.
