Warm water found in disused coal mines has been identified as a potential source of renewable energy.
A study undertaken by the UK’s Nottingham Trend University has established that thermal energy found in groundwater within the mines – which is naturally lukewarm due to heat from the ground – can be used to heat or cool buildings.
The research demonstrates that using today’s technology coal mines could once again be used to provide warmth to thousands of homes.
The successful approach is using a ground source heat pump system to take water from the mineshaft and pump it to the surface. There, the thermal energy in the water is extracted.
A heat pump is able to produce much higher temperature than the original mine water by condensing the energy and circulating it in a separate central heating-type system. The cooler groundwater is then returned to the mine where it becomes lukewarm again by the heat ground from the ground, and the cycle starts again.