They are relics of Scotland’s industrial past and have lain disused underneath Scotland’s biggest city for decades.

But abandoned coal mines in Glasgow’s East End are experiencing a new lease of life thanks to an innovative project which could transform them into renewable energy sources.

Scientists believe untapped mine water underneath Dalmarnock and Rutherglen’s Cuningar Loop could generate geothermal energy to help heat homes and businesses.

The UK Geoenergy Observatory in Glasgow has been studying the sites for a number of years and has now completed a first survey of the water circulating up to 88m below the city.

The only facility of its kind in the world, the observatory has used boreholes to yield important data on the status of the mine systems and the role they could play in decarbonising energy supplies.

Alan MacDonald, of UK Geoenergy Observatories, said: “The latest data show that the boreholes of the Glasgow Observatory are well-connected to the flooded mine workings.

“We discovered that the mine water between 50 and 90m below Glasgow is 11-13C. This compares to Scottish groundwater, which has an average temperature of 10C. Understanding the temperature underground and how it varies will help us understand the heat energy resource.

“We’ve also established that the mine workings are connected and that the water can move easily through them.

“This all shows that the Glasgow Observatory is an excellent site for mine water heat research.”

He added: “The hydrogeological data we’ve gathered will form a baseline for all of the science that will take place at the Glasgow Observatory over the next 15 years.

“The data from these 12 boreholes in Glasgow will help scientists around the world understand the subsurface and geothermal energy better.”

The scientists completed pumping tests and collected samples from 10 of the observatory’s 12 boreholes, which range from 16 to 199m deep and are fitted with hundreds of state-of-the-art sensors.

The results confirm that scientists will be able to use the boreholes to better understand how thermal energy in mine water could be used as an energy source for homes and industry.

It is estimated that a quarter of all UK homes and businesses, some 9m buildings, sit on former coalfields. The industry powered the British economy for more than a century but the last deep mine in Scotland, at Longannet, Fife, closed in 2002, while the last in the UK, in North Yorkshire, closed in 2015.

The boreholes in Rutherglen are on the site of the Former Farme Colliery which closed in 1921.

Alison Monaghan, geologist and science team lead for the Glasgow Observatory, previously told The Herald: “Across the world there are already small schemes that use the technology of mine water geothermal and the first couple of years of what we’re doing in Glasgow should have a big impact as to how more widely the technology could be used.

“Over the 15 year timescale there will be lots of different science questions about how long these resources can be used for and the thing you need to do to keep the scheme working over a long timescale.”

She added that the project is not just about removing heat but also re-injecting and reusing it as well storing it underground when not in use - helping to meet climate change targets globally.

“Any spare heat can be stored in summer and extracted in the winter when it is most needed, using the underground as an inter-seasonal store,” she said.

“That’s another area that could help mitigate climate change. Storing renewable energy is a real challenge so that’s one of the things people might want to use the observatory for.”

The Glasgow Observatory is funded by the Natural Environment Research Council (NERC) and the British Geological Survey (BGS) as part of the £31 million UK Geoenergy Observatories Project.