Abandoned coal mines could heat UK homes again
A research project from Nottingham Trent University has discovered disused coal mines as a viable source of renewable thermal energy in the UK.
The two-year study, conducted in partnership with renewable energy firm Alkane Energy, found that residual heat found in mine groundwater can be condensed and used to heat and cool buildings.
The Innovate UK-funded project explored redundant mines over a 30km area that have the potential to produce enough energy to heat 45,000 homes.
A ground-source heat pump pumps water from the mine to the surface where the thermal energy is extracted using a heat exchanger. The temperature of the water is increased by condensing the energy and re-circulating it through a central heating-type system. The water is then returned to the mine to naturally reheat.
Even when solar and wind energy are insufficient to power the pump, the thermal energy was found by the study to be four times more efficient when running on mains electricity than a 90% efficient modern gas boiler.
The system has so far been tested at the former Markham Colliery in North East Derbyshire where the heat was used in an industrial building owned by Alkane.
"In a way, we may never have previously envisaged, coalmines could once again be used to provide warmth to thousands of homes across the UK," said Professor Amin Al-Habaibeh from of the School of Architecture, Design and the Built Environment, who led the study.
"But the key difference between yesteryear and tomorrow is that we now have the ability to harness their energy potential in a completely sustainable way.
"Alkane has traditionally utilised gas contained in disused coal mines to power its core electricity generation business," Alkane Energy project director Keith Parker said: "The utilisation of heat from mine water gives rise to a further opportunity to make use of the mines to provide green, sustainable energy to homes and businesses in the UK."