China Turns Abandoned Coal Mines Into Home Cooling Systems 2026

China has found an unexpected use for its abandoned coal mines: cooling homes. In the mining city of Xuzhou, a pilot project at the Woniushan mine is using flooded mine water to provide air conditioning to 100 households, turning a liability into a renewable energy asset.

The project, led by the heating company of the Xukuang Group, taps into water that naturally stays below 20°C in the flooded mine. This water is pumped through a heat exchanger connected to underfloor heating systems, providing cooling in summer and heating in winter.

Why Abandoned Coal Mines Are a Problem

As China transitions away from coal, many mines have closed, leaving behind vast infrastructure and environmental challenges. The Woniushan mine, like many others, suffers from flooding due to groundwater and rainwater infiltration. This water must be managed to prevent contamination and subsidence.

Traditionally, such mines are sealed or remediated, but that can be costly and does not address the potential resource they represent. The Xuzhou project offers a new perspective: instead of treating mine water as waste, it can be used as a renewable energy source.

How the Mine Cooling System Works

The system relies on the stable temperature of mine water. In summer, the water, kept cool by the earth, is circulated through a heat exchanger that absorbs heat from the building's underfloor heating circuit. The warmed water is then returned to the mine, where it cools again.

In winter, the same circuit can be used for heating by reversing the process or using a heat pump. According to Zhang Tao, head of the scientific research project at Xukuang Group's heating company, the underfloor system typically uses water at 40°C for heating in winter, while in summer, the same circuit carries cold water.

• Uses flooded mine water that stays below 20°C year-round.
• Provides cooling for 100 homes in the pilot phase.
• Leverages existing underfloor heating infrastructure for distribution.
• Reduces reliance on traditional air conditioning, cutting electricity demand.
• Repurposes abandoned industrial sites, avoiding new construction.

Environmental and Economic Benefits

This approach offers significant environmental benefits. Traditional air conditioning consumes large amounts of electricity and uses refrigerants that can contribute to global warming. By using the constant temperature of mine water, the system reduces both energy use and emissions.

Economically, repurposing abandoned mines can create local jobs and reduce the cost of cooling for residents. It also extends the life of existing infrastructure, such as the underfloor heating systems already installed in many Chinese homes.

Comparison with Other Geothermal Systems

Geothermal cooling is not new, but using flooded mines is a novel twist. Conventional geothermal systems require drilling deep wells, which can be expensive. Mine water systems, on the other hand, tap into existing voids and tunnels, reducing drilling costs.

Challenges and Future Prospects

Despite the promise, challenges remain. Mine water can be corrosive and may require treatment before use in heat exchangers. The availability of suitable mines is limited to regions with abandoned coal mines and district heating infrastructure. The background to this story is set out in Spain Flooded a 300-Meter Coal Mine: Europe's Largest Artificial Lake. A related thread runs through Spain Demands €31 Million Back from Asturian Coal Mine Revival. Earlier coverage in Abandoned Coal Mine Cleanup: Who Pays for Queensland's Mess shows how the argument developed.

Nevertheless, the Xuzhou pilot is a proof of concept. If successful, it could be replicated in other mining regions in China and beyond. The project aligns with China's goals to increase renewable energy use and reduce carbon emissions. A closer look at the same subject appears in China Turns Coal Mine Scars Into Thriving Farms and Greenhouses. Anyone following the wider picture can start with India Coal Production Plans Drive Global Mining Surge. The same theme surfaces in Australia's New Environmental Agency Approves Controversial Coal Mine, which takes a different angle.

As the world seeks to transition to clean energy, innovative solutions like this demonstrate that abandoned fossil fuel infrastructure can be part of the solution. The Woniushan mine may be a sign of things to come. Context on how this played out before sits in How Geothermal Heating Works: A Complete DIY Guide. A companion piece, Retired Couple Wins Landmark Coal Mine Climate Case in Australia, approaches the same subject from another angle.