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Drilling to begin at UK’s first geothermal power plant

Two wells will be drilled through granite rock near St Day, the deepest of which will reach 4.5 kilometres.
Two wells will be drilled through granite rock near St Day, the deepest of which will reach 4.5 kilometres.

Drilling will start this week at what could become the UK’s first deep geothermal electricity plant in Cornwall.

Two wells will be drilled through granite rock near St Day, the deepest of which will reach 4.5 kilometres.

Geothermal Engineering Ltd says the aim of the project is to demonstrate the potential of geothermal technology to produce electricity and renewable heat in the UK.

It is believed that the plant at the United Downs Industrial Estate has the potential to supply up to 3MWe (Mega Watt electrical) of electricity, enough to power 3,000 homes.

Once drilling at the site is complete, water will be pumped from the deepest well at a temperature of approximately 190C.

Geothermal energy production
(PA Graphics)

This water will be fed through a heat exchanger at the surface and 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.

Geothermal technology is described as a “continuous” energy source because it does not suffer from peaks and troughs experienced by other sustainable power sources.

Developers hope the technology used at the facility could be used in other locations in Cornwall and Devon.

Similar plants have been developed at Insheim and Landau in Germany.

Dr Ryan Law, managing director of Geothermal Engineering, said geothermal resources have the potential to deliver up to 20% of the UK’s electricity and heat energy needs.

He added: “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 £18 million project has received £10.6 million funding from the European Regional Development Fund, £2.4 million from Cornwall Council and £5 million from private investors.