Paper No 44 – Abandoned mines as a source of heat and cold – 14th IEA Heat Pump Conference, Chicago, USA
Mining has influenced and shaped the development of humankind for many thousands of years. After closure, these mines are often flooded and then offer a very high potential as a regenerative energy source for heating and cooling. Due to the almost constant temperature between about 10 to 30 °C throughout the year, an independent source of energy is permanently available, which can be brought to the necessary temperature level with heat pumps. In total 116 existing, planned and decommissioned systems were found worldwide. The observation of monitoring results of an example mine ("Reiche Zeche" in Freiberg/Germany) and a comparison to three other locations shows that the parallel use of mine water for heating and cooling can achieve coefficients of performance of the overall system of up to 10. Even with high electricity prices, operation costs for geothermal mine water energy of between 5 and 10 ct/kWhheat are possible. Compared to fossil fuels, at least 50 % CO2 emissions are saved.