Drilling has started this week to build the UK's first deep geothermal electricity plant at the United Downs Industrial Estate near St Day in Cornwall.
Geothermal Engineering Ltd (GEL) want to demonstrate the potential of the geothermal resource in the UK to produce electricity and renewable heat. The plant will supply up to 3 MWe (Mega Watt electrical) of electricity which is enough energy to power 3,000 homes.
The global engineering consultancy, Arup, has signed an agreement to purchase renewable energy guarantee of origin certificates (REGOs) from GEL equating to 9000MWh/year. The REGO scheme is a UK Government sponsored scheme which enables companies to secure green energy for their operations. The deal will allow the firm to supply zero carbon electricity to all of its offices in the United Kingdom.
Two deep geothermal wells will be drilled into the granitic rock beneath the site, the deepest of which will reach a ground-breaking 4.5 kilometers. Water will be pumped from the deepest well at a temperature of approximately 190C, fed through a heat exchanger at the surface and then re-injected into the ground to pick up more heat from the rocks in a continuous cycle. The extracted heat will be converted into electricity and supplied to the National Grid.
The electricity and heat energy produced by this type of low carbon, renewable energy source is continuous (24/7) as geothermal energy does not suffer from the peaks and troughs that many other sustainable power sources are subject to. It is hoped that the innovative approach applied through this initiative should be repeatable at other suitable sites in Cornwall and Devon. The proposed plant is following on from the success of similar plants in Insheim and Landau in Germany.
Dr Ryan Law, managing director of Geothermal Engineering Ltd, said "The largely untapped geothermal resources in the UK have the potential to deliver up to 20% of the UK's electricity and heat energy needs in a reliable and sustainable way. As coal fired power stations are switched off, the need for renewable, baseload energy can only increase. It is incredibly exciting to see this pioneering project getting off the ground in what we hope will be the start of many similar initiatives across the UK."
The project has received approximately £18 million in funding, including £10.6m from the European Regional Development Fund, £2.4m from Cornwall Council, £5m from private investors through Abundance Capital. Delivery partners for this project include GeoScience Ltd, The British Geological Survey, and the University of Plymouth Sustainable Earth Institute.