A sustainable and low-carbon source of heat to keep residential and commercial buildings warm in the U.K. is being investigated. Geothermally heated water in abandoned coal mines can potentially be tapped to provide heating services for homes and businesses.

The process entails pumping water from flooded mine workings underground and bringing it to the surface where heat exchangers and heat pumps recover this heat and boost the temperature further. A clean loop of heated water is then transferred into buildings for everyday use. The cooled mine water is then returned underground to be naturally reheated and reused. More than 300 buildings in Gateshead have been supplied with heating by such a mine water heat scheme during the last year, demonstrating the feasibility of this approach.

The interactive map viewer shows heating demand in Britain over recorded abandoned coal mine works. Source: U.K. Coal Authority/U.K. Ordnance Survey

The U.K. Ordnance Survey has provided geospatial and location mapping data to the U.K. Coal Authority to determine buildings and communities that could benefit from this heating scheme and expand it nationwide. Preliminary data identify just over six million homes and over 300,000 offices and businesses above abandoned coal mines, although it is too early to say exactly just how many of these addresses could ultimately take advantage of the heat recovery technology.

The data from this project can be viewed on the mine water heat tab of the U.K. Coal Authority interactive map viewer.