Re:engineer

Our researchers have developed new technology that takes the water from the abandoned mines to create green, sustainable energy to homes and businesses. With the introduction of Ground Source Heat Pumps (GSHPs) into the abandoned coal mines, warm water can be extracted (with cooler water then injected back into the same shaft) to provide heating to buildings.

This provides an opportunity for efficient heating and cooling applications. Furthermore, there is an associated reduction in overall carbon emissions, with GSHPs generating more thermal energy than they consume in electricity.

The technology is straightforward, working similarly to a refrigerator or air-conditioning system by extracting the heat from underground water and using it to warm buildings. It produces no noise or local air pollution, and it is also three or four times more efficient than a standard electric heater or gas boiler.

The team have tested this new technology using two systems: one at Markham Vale and one at the National Coal Mining Museum for England. In collaboration with Alkane Energy, the site at Markham Vale was converted into a water-pumping station to remove water from the local mine. Using a GSHP, that water was used to heat the office building on site. When compared to a modern boiler with 90% efficiency, the GSHP will produce 300% and 433% more energy for the same cost.

The use of water from abandoned coal mines has revealed another opportunity for our researchers: in the UK, coal mining technology programmes already pump circa 112 million megalitres of water for environmental reasons - such as avoiding the pollution of drinking water, springs and rivers, for example. The new technology developed by NTU’s researchers could use this water, which is being pumped anyway, and potentially generate an additional 63 megawatts of heat, which should be consistent year after year. This is equivalent to the heat generated by 31,500 kettles.

It doesn’t stop there – this new approach can be integrated with other heating technologies, and in many cases it can be implemented with existing building infrastructure, providing a low-cost solution to an expensive problem.

Successful, large-scale studies have already taken place to show how effective this repurposing technology can be. In Asturias, Spain, a hospital and university building are already being heated using coalmine water. NTU’s research shows that this technology could give the world’s abandoned mines a new, greener lease on life, whilst also reducing carbon emissions and lowering energy costs.

The team is currently exploring further collaborations with key partners to develop more efficient heating systems using coalmine water.

Read the team's latest publication on this research.