| Abstract |
Mine water geothermal technology is a developing renewable energy approach that utilizes the consistent thermal properties of mine water for both heating and cooling purposes. Although the mining sector is vital for supplying key minerals, closed mines are often left unused. These abandoned sites offer a new opportunity as potential sources for thermal energy storage and geothermal energy. This paper explores both the potential and challenges of using water-filled, abandoned mine workings for thermal energy storage, with a particular focus on Australia, given its extensive mining history. Considering the Bendigo-Ballarat fields in Victoria as a representative case study, the study evaluates their technical viability under Australia’s distinct geological and climatic conditions. Additionally, the study introduces a coupled fluid-flow and heat transfer model aiming to assess the impact of operational and geological parameters and seasonal temperature changes on energy storage and heat extraction. The results indicate that while optimized flow rates enhance heat recovery, overly high circulation can lead to efficiency losses due to temperature equalization. Over 30 years simulations considering parameters such as operation mode, scheduling, idle-band range, and solar-assisted recharge showed that adaptive operation strategies improved mine-water thermal balance by 28–37%. The study also highlights the critical role of geological and hydrological conditions in influencing the mine’s energy storage capabilities, especially for managing seasonal energy demands. |