Euronews.green reports that an abandoned coal mine offered heat to the town of Gateshead over the last six months with emissions-free energy, by flooding the tunnels with warm water.

John McElroy, cabinet member for the environment and transport at Gateshead Council, said that "what we have in Gateshead is a legacy from the days of the coal mines, which was dirty energy. Now we are leading the way in generating clean, green energy from those mines."

Scientists believe that Britain's abandoned mine shafts could be the answer to the country's quest for renewable power, should they be filled with around 2 billion cubic meters of warm water.

Gareth Farr, head of heat and by-product innovation at the Coal Authority, explained that "recovering heat from mine water below the ground within abandoned coal mines provides an exciting opportunity to generate a low carbon, secure supply of heat, benefitting people living or working in buildings on the coalfields."

The deeper it reaches in mining tunnels, the warmer water gets. Usually at around 10 to 20 degrees Celsius, it can get as warm as 45 degrees in mine shafts as deep as one kilometer. Through special boreholes, water can be extracted and deployed to heat pumps, which can use it as a power source to heat buildings.

Once the water cools down, it can be reintroduced into the mine shafts, where it will warm up again and extracted over and over.

Heat pumps can in fact be a great solution to warm a house and even an industrial building, as it can be as much as five times more efficient than a central heating unit.

Back to Gateshead, the town makes use of mine-stored water to heat up 350 homes, its college, an art gallery, one manufacturing site and administration buildings.

The city of Heerlen in the Netherlands started tapping into this power source back in 2008, when it used a similar concept to heat up 500 homes and commercial facilities, reducing the heating-related footprint by some 66%.

With some 200 deep-surface mines, European countries could make use of them to offer sustainable heating for their citizens and industries, resulting to impressive CO2 reductions.