In the U.K., the government is investing in the assessment of the potential for old coal mine sites to be converted into renewable energy hubs. As many governments around the globe aim to phase out the use of coal, researchers are exploring the potential for old mining sites. Rather than be left abandoned, ex-coal production sites could be used for a multitude of purposes, from solar energy to geothermal operations, supporting a green transition and reinvigorating the economies of previous energy hubs.
In the U.K., the metro mayor for the west of England, Dan Norris, is investing £1.5 million in the exploration of over 100 coal mines in Somerset and South Gloucestershire to explore the potential for supplying renewable heat sources in the region. The mines in this region were emptied of coal and then closed and flooded, as the pumps were turned off. The water in the mines is heated by geothermal energy, with heat coming from the Earth’s core, allowing it to reach temperatures of around 20oC. The idea is that the water is extracted, and the heat is separated from the water to be used in heat pumps in homes and businesses across the country. New geothermal operations in existing coal mines could provide vast amounts of low-carbon heat. In addition, the water is pumped back into the mines to be recycled, making it a highly efficient process.
There has been an increasing focus on the potential use of heat pumps in the U.K., as well as other countries around the world. Heat pumps can replace furnace and air conditioning equipment, providing low-carbon heating. Several cities worldwide have already introduced bans on furnaces in new buildings, starting later in the decade, thereby increasing the demand for greener alternatives such as heat pumps. The U.S. and France are both now developing their heat pump manufacturing industries to respond to this demand.
Dan Mallin Martin, a hydrogeologist with the Coal Authority, the public body responsible for managing the effects of past coal mining, explained, “The transition to heat pumps as an energy source is very important and that’s one of our options for decarbonising our heating requirements across the U.K..” He added, “With heat pumps, ground source options and mine water, we can feed into that decarbonisation, especially if we couple it with green electricity like solar panels and wind.”
There have already been successful geothermal projects on old coal sites in the U.K., including the Gateshead mine in the north of England. In March 2023, the Gateshead Energy Company launched geothermal operations at the site, making it the largest mine water heat network in Great Britain and one of the largest in Europe. The project, funded by the Heat Network Investment Project (HNIP) and the Gateshead Council, took three years to develop. Now, heat can be extracted from 150 metres underground to provide hot water to hundreds of homes and businesses across the region. The company hopes to grow the network for use in a new conference centre, a hotel development, and an additional 270 privately owned homes. This could help reduce CO2 use by around 1,800 tonnes a year.
And it’s not just the geothermal energy potential that researchers are exploring when it comes to repurposing old coal sites. With many coal operations covering vast amounts of land, they are ideal for conversion into solar farms. Installing solar energy infrastructure on degraded lands like mining sites and landfills is a low-cost way of transforming the sites into clean energy hubs. Using ex-mining sites can help save time and costs associated with project development, as many sites already have vital infrastructure, such as transmission lines and roads. It can also revitalise the economy of former energy hubs, creating jobs and providing clean energy for communities.
In Virginia, USA, the Nature Conservancy – an NGO, has converted several abandoned coal mines into solar energy operations, big enough to provide renewable energy to the grid. It was one of the first examples of transforming coal sites into solar farms and the organisation hopes it will encourage the rollout of similar projects countrywide. The Nature Conservancy partnered with solar developers, such as Dominion Energy and Sun Tribe to develop the projects. The mine sites are well-suited to the transformation as they are situated on vast flat areas exposed to sunlight.
Daniel Kestner from the Virginia Department of Energy explained, “In the coalfield region, there are about 100,000 acres that’s been impacted from mining… better to build on a lot of these mine sites than some prime farmland or some areas that maybe don’t want solar in their community.”
As governments look to increase their renewable energy capacity and reinvigorate former energy hubs, the repurposing of coal sites could provide the perfect opportunity for transformation. There is huge potential for the development of both geothermal and solar energy operations, which could help bring jobs and revenue back to long-neglected mining communities, as well as support a green transition.
Please note the image portrayed is not linked to this article.