Maps revealing the extent to which heat is stored in Britain’s abandoned coal mines have been released to help develop low carbon heating for homes.
A quarter of the UK’s population live above abandoned coal mines, which are warmed by natural geothermal processes, the Coal Authority said.
Where the mines are flooded, the mine water can be used as a sustainable heat source for district heating systems that could replace conventional gas boilers for heating and hot water in homes and other buildings.
The British Geological Survey (BGS) and Coal Authority have released an interactive map showing where the mines are and the extent to which temperatures increase with depth.
The mapping tool will be freely available for use by developers, planners and researchers to identify opportunities to look into the use of mine water as a heat source, the two organisations said.
The Government has set out plans for around one in five buildings to use a largely low carbon district heat network by 2050, and disused mines could be a source of heat for such projects.
They are already starting to be used: earlier this year, Gateshead Council secured a £5.9 million grant to double its district heating network, including installing technology to extract heat from water in underground mine workings.
And a garden village at Seaham, County Durham, is being developed next to Dawdon mine water treatment scheme, heat from which will be used for the first large scale mine energy district heating scheme in the UK, the Coal Authority said.
BGS geoscientist, Gareth Farr, who led the map project said: “This has been a very exciting piece of work. It’s the first time we have been able to visualise the temperature of Britain’s coalfields.
“We have found records of heat temperatures going back over 100 years and compared them to temperatures in the mines now, and found them to be quite similar.
“This is a clear indication that geothermal processes that create this heat will be here for a long time to come.”
The Coal Authority’s head of innovation, Jeremy Crooks, said: “When miners were working in hot, dusty conditions, they would not have known that their efforts and the heat they worked in, would one day create a sustainable source of energy for hundreds of years to come.
“We are currently reviewing over thirty potential heat network opportunities using geothermal mine energy.
“Seaham Garden Village and Gateshead are the first two such schemes to secure funding from the Government’s £320 million Heat Network Investment Programme, with others to follow.”
He added: “It’s ironic that mining coal, a fossil fuel, would provide access to a low carbon, clean air, energy source that will last far longer than the 200 years of intensive mining that created this opportunity.
“The maps we’ve jointly produced is a visual indication of how real and exciting this opportunity is.”