A town in England has been using an old coal mine as a source of renewable energy since last spring. The project involves using warm water from the mine’s tunnels to heat homes and businesses in the surrounding area.
The town of Gateshead, where the project is taking place, has transformed from relying on dirty energy to leading the way in generating clean energy from the old mines.
Britain’s flooded coal mines hold a vast amount of warm water. Geologists believe that these mines could be some of the UK’s largest untapped sources of clean energy.
The aim is to establish a reliable, low-carbon heating source by recovering heat from mine water. This approach not only addresses renewable energy needs but also contributes to the revitalization of communities that were heavily impacted by coal mining closures.
The Gateshead initiative has been declared a success. The project showcases the potential for using abandoned mining tunnels as a clean energy source.
With approximately 25% of UK homes built above former mining tunnels, the UK has the potential to become a world leader in geothermal energy.
The science behind green coal mines
Deeper underground, the temperature of mine water progressively rises. The typical temperature ranges from 10 to 20 degrees Celsius. However, mine water can reach up to 45 degrees Celsius at depths of 1 kilometer, according to Euronews.
When mixed with the underground rocks, the water often becomes contaminated with harmful substances. However, as a thermal resource, it presents an opportunity for extraction. Workers can drill boreholes and bring it to the surface.
Through the use of heat pumps and extractors, the water is compressed. This significantly increases its temperature. Then, the water is distributed to homes through heating infrastructure.
After its heat is absorbed by surrounding buildings, the water can be returned to the mine system to be reheated.
One of the advantages of mine water heat is its year-round usability. Mine water is unaffected by seasonal changes. Therefore, it can be used for both cooling and heating purposes in homes.
Mine water research
In March 2023, Gateshead Council launched its mine water project, now one of the largest in Europe. Secured funding from the government enabled the installation of 5 kilometers of heat network pipes. The funding also enabled the installation of boreholes and a heat pump energy center with a capacity to generate 6 mega-watts of mine water heat.
This project now provides reliable low-carbon heating to 350 high-rise homes. It also heats a college, an art gallery, multiple office buildings, and a large manufacturing site.
The Coal Authority and its partners have been conducting research on the potential of recovering low-carbon heat from abandoned coal mines for several years.
The UK Geoenergy Observatory (UKGEOS), located in Glasgow, is one of the primary research facilities for this field of study.
In recent years, an abandoned mine in Glasgow has been flooded. The water temperature in the mine is approximately 12 degrees Celsius. In the summer of 2021, a dozen boreholes with numerous sensors were drilled into the site.
The Glasgow study provided valuable data on flooded mines. The study shed light on water flow, temperature, replenishment speed, and reheat rate.
The Department for Business, Energy and Industrial Strategy (BEIS) is currently investing £31 million (€37 million) in the Glasgow Observatory and a related project in Cheshire.
Image Source: Geographical, https://shorturl.at/bEV19