Momentum building for geothermal in UK with good news from the United Downs project

Drilling rig at United Downs project site, Cornwall/ UK (source: GEL Ltd.)
Alexander Richter 14 Sep 2020

With good testing results for the UK’s first geothermal power project at United Downs in Cornwall and the recent start of the geothermal pool in Penzance, there is great momentum building up for more to come.

UK-based Geothermal Engineering Ltd continues to push forward with the United Downs geothermal power project in Cornwall and has recently completed the first phase of testing on the wells.  The production well is 5.275km deep and the temperature is now confirmed at 188 degrees Celsius.  The project also successfully retrieved side wall cores from the open hole section of the well (between 4 and 5km) and these are now being analysed to better understand the fracture flow system.  These are the deepest cores ever retrieved in the UK.

Production and injection testing of the wells have also proved the concept that the deep fracture zone target has much higher flow rates than the surrounding granite.  Further, as part of the production testing on the deep well, the water has been sampled and shown to have very high levels of lithium content (concentrations up to 260mg/l).   Potentially the highest in the world, with very low levels of magnesium.

Further well testing will be undertaken in October and the project aims to produce power in late 2021.

Ryan Law, Founder and Managing Director of Geothermal Engineering Ltd said, “the recent successful well testing at United Downs has been another step forward towards producing geothermal power in the United Kingdom.  It’s been a long haul to get here but the team can now see that there is light at the end of the tunnel.  The flow results from the deep fracture zone are encouraging and the science behind the project (including European research projects) has helped to refine and develop the concept.   The lithium results are also very exciting, we had always expected the levels to be high but the water chemistry does suggest that low carbon lithium extraction will also be possible at the site.  We look forward to developing that concept further over the next 18 months as part of a UK Government funded trial.  The combination of deep geothermal power, heat and lithium could be a big part of the future in Cornwall.  Things are finally starting to look positive for deep geothermal development in the UK.”

With the recent opening of the geothermally heated pools in Penzance (another Geothermal Engineering project), ongoing efforts for utilising geothermal energy from abandoned coal mines and the great indications for more to come from the United Downs project, clearly we see a certain momentum building for geothermal energy in the UK. So stay tuned.