Author: Sophie Squires
A landmark moment for renewable energy takes place at the Eden Project in Cornwall today (Monday 19 June).
The UK’s first operating deep geothermal heating plant since 1986 is being switched on.
The process of drilling deep into the granite at the home of the world-renowned Biomes in Cornwall was finished in 2021.
Eden Geothermal Ltd (EGL) has now completed the heat main and plant and is ready to supply heat to the Eden Project and its new state-of-the art nursery, Growing Point.
The well has a vertical depth of 4,871 metres (just over 3 miles). The measured depth - the actual length of the well - is 5,277 metres (nearly 3.3 miles), the longest geothermal well in the UK.
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 well via the outer ring.
The heat is delivered via a 3.8km heat main, at around 85 degrees Centigrade, which will supply Growing Point and Eden’s Biomes and offices.
Gus Grand, CEO of EGL, said: "This is a big moment for Eden Geothermal and renewables in the UK, but we’ve only just begun: in the race to decarbonise, progress has been slow for heat technologies, behind electricity and transport, but geothermal energy, with its small surface impact, can be used in urban areas and for large institutions, factories, hospitals, universities and schools.
"This project is a great demonstration, heating a whole rainforest and commercial nursery, with hopefully a distillery on the way."
The Growing Point nursery has been built between the geothermal site and the Biomes. It serves as a demonstrator of regenerative sustainability and a circular system in both its construction and operation, eliminating the need for a pre-existing off-site nursery, reducing food-miles and dependence on fossil fuels.
It will also enable Eden’s Living Landscapes Team to produce all the plants for the Rainforest Biome, Mediterranean Biome Outdoor Gardens and retail, as well as food for the hundreds of thousands of visitors Eden welcomes every year.
Rob Chatwin, Group CEO of the Eden Project, said: "We are developing new ways to grow and new ways to encourage people to think differently about plants and the planet.
"We have built a landmark sustainable nursery – a pillar of our wider ambitions for the future impact and expansion of the Eden Project – and it will help us accelerate massively our mission towards a climate positive future."
The geothermal project has been delivered by Eden Geothermal Limited (EGL), a three-way partnership between Eden Project Limited, EGS Energy Limited, a geothermal development and consultancy group, and BESTEC (UK) Limited, affiliated with BESTEC GmbH, the specialist geothermal developer and drilling advisor.
EGL secured £24 million from a combination of European Regional Development Fund, Cornwall Council and commercial funding from GCP Infrastructure Investments Limited, an investment trust advised by Gravis Capital Management Ltd, in order to fund the research project.
