Advocates of using minewater for heating regard it as having particularly significant potential after the UK set the ambitious goal earlier this year of net zero greenhouse gas emissions by 2050.
A quarter of all UK homes and businesses, some 9m buildings, and most of its largest cities outside London sit on former coalfields. Coal mining, which employed 1.25m people at its peak, powered the British economy for well over a century but the last deep mine closed in 2015.
One of its underground legacies is the warrens of galleries through which run an estimated 2bn cubic metres of water, heated by surrounding rocks to 12-16 degrees Celsius.
The Coal Authority, which estimates there is enough geothermal energy in coal mines to heat 180m homes, is preparing a minewater energy “heat map” of Britain.
