Plans are unfolding to create the UK’s first geothermal power project near Redruth Cornwall. United Downs Deep Geothermal Power aims to be in operation by 2020. 99.9% of the planet is at a temperature greater than 100 degrees Centigrade. The geothermal gradient (temperature increase with depth) in Cornwall is higher than other areas of the UK and extensive research from the mid-70s has pin-pointed opportunities for geothermal energy.
The proposed power plant will be built and operated by Geothermal Engineering Ltd. Initially the plant will supply up to 3.15MW of electricity to the grid. In November 2011, Geothermal Engineering was awarded a grant of £6m from the European Regional Development Fund towards the cost of the project and drilling of the first well was expected to begin in late 2012. However in April 2013, the grant was withdrawn due to the company’s failure to attract private funding for the project. In 2017, sufficient capital was raised by renewable energy crowdfunding specialists Abundance Investment and the project is now going ahead.
Two wells will be drilled into fractured granite. Drilling should begin in the first quarter of 2018 and take around five months to drill a well 2.5km down. This will be followed by a deeper well of 4.5km, creating a circuit for water to be pumped down the shorter well and return up the deeper well. The very hot pressurised water will be converted into electricity using a steam turbine. The water for charging the reservoir will come from flooded mines, not from the local water supply. If all goes as planned, the Redruth operation could be operational in 2020. Ultimately, geothermal could provide as much as 1,000 megawatts of capacity in Cornwall.
Unfortunately the complicated structure of the rocks in Cornwall make this a risky project and as this is new technology to investors finding funding has been extremely difficult.
Another geothermal project that Geothermal Engineering hopes to complete is to provide geothermally heated water for the open air Jubilee Pool in Penzance, Cornwall.
The Eden Project in Cornwall was has also put forward a proposal for a geothermal engergy plant to provide all it’s power requirements and enough power for 40,000 local homes, but it is struggling to find funding.