This British village is heating homes with water from a flooded coal mine

Around one in four homes in Britain sits on top of a seam of coal.

Many of those homes could soon be enjoying low-carbon, sustainable heating through a technology that could have a global impact.

The secret is mine water: vast underground reservoirs that have collected as abandoned coal mines have flooded. Thanks to the temperature of the Earth’s crust, the water is warm - warm enough to heat a house, with a little assistance from technology.

Many mine water-powered heating projects are planned in Britain for the coming years - pumping up water, heating homes and sending it back down for reheating: a circular model that other mining nations could replicate.

One project will see 1,500 new homes built in Seaham Garden Village in north-east England. When completed, they will have radiators filled with water heated geothermally, in the nearby disused Dawdon mine.

The scheme is an elegant solution, as the water from the mine was being pumped to the surface for treatment anyway - mine water being so salty it can sometimes contaminate underground drinking water supplies.

The pumping process helps further warm water already heated by underground temperatures to a constant 18-20 degrees Celsius.

Such schemes are not without their problems - the BBC has reported that a small trial scheme in Scotland had to be abandoned due to costs.

However, the UK government is upbeat about the potential of larger schemes. “I think it’s potentially transformational,” Energy Minister Kwasi Kwarteng told BBC News.

“We have this huge historic legacy in terms of coal, and being able to use that footprint and turn it into a source of green energy – that’s incredibly positive.”

Around 30 mine water heating schemes are now planned across the UK. If they succeed, they could help with the UK’s ambition to reach net zero carbon emissions by 2050.

Britain’s need to heat homes and businesses accounts for some 40% of the UK's CO2 emissions.

If mine water schemes were scaled up and replicated globally they could potentially help reduce one of the biggest demands for fossil fuels.

Mine water heating schemes could help prioritize sustainable development in the wake of the COVID-19 pandemic.

The World Economic Forum is calling for a Great Reset - a commitment to build a fairer, more sustainable and more resilient future following the coronavirus crisis.

“We only have one planet and we know that climate change could be the next global disaster with even more dramatic consequences for humankind," said Professor Klaus Schwab, World Economic Forum Founder and Executive Chairman. "We have to decarbonize the economy in the short window still remaining and bring our thinking and behaviour once more into harmony with nature.”

In recent decades, the UK’s coal industry has declined dramatically - from fuelling an industrial revolution to an increasingly minor resource in power generation today, as gas and renewables take its place.

A record low 2.2 million tonnes was produced in 2019 - and on 8 June, the UK reached the milestone of two months in a row without using electricity from coal-fired power stations, according to the country’s National Grid.

However, the extensive coal industry of the past has left a huge legacy: a network of deep mines, containing a resource few would have predicted might one day have a value - flood water.

There is also a legacy of people - with millions living around old mines, in communities that grew because of the coal industry. And after the hardship caused by industrial decline, those communities now stand to benefit.