Eden project to tap Earth's heat

The Eden project in Cornwall could become home to the UK's first geothermal plant which will use heat from beneath the earth's surface to provide electricity and hot water.

The scheme would make use of the vast amounts of thermal energy stored in the granite outcrops that occur 3-4km below the ground in Cornwall.

Eden and its commercial partner EGS Energy believe the project could spearhead the way for a series of plants that could lead to Cornwall's 'hot rocks' providing up to 10% of the UK's entire electricity requirements.

The power plant at Eden would comprise of two boreholes, both around 3-4km deep. Cold water would be circulated down one where it will be heated by the surrounding granite before being pumped up from the adjacent borehole at around 150ºC. The steam will drive a turbine to create up to 3MW of electricity, while the hot water left over could be used to provide heating to local homes or to grow fruit and vegetables out of season.

Roy Baria, technical director of EGS Energy says the geology in the vicinity of the Eden Project is ideal for creating the power plant and its reservoir. “We would not only expect to be able to supply virtually all of the Eden Project's power and heat requirements but generate surplus power that could be fed into the grid to help meet the governments carbon dioxide reduction and renewable generation targets.”

The next stage is to get planning permission and funding for the scheme. Guy Macpherson-Grant, managing director of EGS Energy says they are already in talks about raising funding for the project from the private sector.