WARM water in old coal mines across County Durham could be used to bring eco-friendly heating to homes, researchers claim.

In February, Durham County Council declared a “climate emergency” backing calls for urgent action to reduce carbon emissions.

This included setting targets to reduce emissions by 60 per cent by 2030 and to investigate actions to make the county “carbon neutral” by 2050.

While council officers have started to develop a plan to meet these targets, researchers have said the answer could lie underground.

Professor Jon Gluyas, of Durham University’s Earth Sciences Department, said coal mine water could be used to heat buildings and reduce reliance on fossil fuels.

“One of the most interesting things for me as a geologist is what we have beneath our feet, the heat beneath our feet,” he said.

Councillors heard half of all energy in the UK is used for heating, with 77 per cent of energy generated from burning fossil fuels.

In County Durham, researchers at the Durham Energy Institute believe they can use the coal mine water to heat a minimum of 100,000 homes.

While rolling out the technology at scale would have cost implications, councillors heard, some projects are already in the pipeline to test the energy potential of mine water.

This includes using the tech to heat the swimming pool at the Louisa Centre in Stanley.

Council officers have also been taking notes from existing “district heating schemes” in Gateshead and are in talks about using the technology for new homes in Seaham. Prof Gluyas added: “We have a place to start, without doubt the lowest risk and opportunity is heat from abandoned coal mines.

“Heat has a lower density in terms of its energy but if we only need heat and 50% of our requirements nationally is for heat, why are we burning gas to heat our bathwater? If we start to decarbonise heat, we will meet our emissions targets. As far as the heating component goes there is a solution here.

“Yes it’s difficult and requires a change in infrastructure, we’re capable of doing this if there’s a will to do so and the place to start is here in Durham.”

The comments came at a special meeting of the Environment and Sustainable Communities Overview and Scrutiny Committee. Several councillors and council officers were supportive of the plans, including Adrian Cantle-Jones, from the council’s housing regeneration team.

“We’re sitting on an opportunity to warm the homes in Durham from the industrial legacy we’re all from,” he said. He added that council works to externally insulate older properties in many areas in the borough, combined with the new technology, could help tackle fuel poverty.

Experts said the systems use a “heat exchanger” rather than circulating mine water, which reduces risks associated with erosion or sinkholes.

And an upcoming project also aims to use satellite technology to monitor changes in the earth’s surface and how water is flowing.

To bring the mine water project forward, council bosses are also looking to temporarily transfer a Durham University staff member to work with council teams. Plans to further explore mine water technology could also be included in the council’s new climate emergency plans.

A report linked to the council motion is set to be revealed in July this year.