In the heart of China’s energy transition, a groundbreaking study led by Liyuan Liu from the University of Science and Technology Beijing is transforming the way we look at abandoned mines. These derelict sites, once considered environmental liabilities, are now being repurposed into efficient thermal energy storage systems, offering a promising solution to seasonal energy demands and waste heat utilization.
Liu and his team have developed a sophisticated multiphysics coupled mechanical model for Mine Thermal Energy Storage (MTES) systems. This innovative approach leverages the underground spaces and geothermal resources of abandoned mines, enabling the seasonal storage of surplus thermal energy from renewable sources and industrial waste heat during the summer. Come winter, this stored heat can be extracted for heating services, significantly enhancing energy efficiency.
“The formation of artificial pseudo-aquifers through mine void networks allows contained hydrothermal resources to demonstrate substantial heat supply potential to surrounding areas,” Liu explains. This process not only addresses idle mine risks but also presents a unique opportunity to improve energy infrastructure.
The study, published in the Chinese Journal of Engineering, employed numerical simulations to assess the long-term operational performance of the MTES system. Over a decade of simulated operation, the system demonstrated impressive results. After injecting water at 80°C, the residual temperature remained at 35.5°C (44.4% retention rate) during the first year. Winter extraction temperatures progressively increased annually, with the tenth-year output temperature showing a 10.3°C increase compared to the first year.
The research also highlighted the system’s stability and safety. Stress analysis confirmed that thermal storage operations maintained roadway stability, paving the way for large-scale engineering applications. Liu’s team used the Distance-based Generalized Sensitivity Analysis (DGSA) method to identify critical parameters affecting system efficiency, with summer injection temperature and injection rate emerging as the most influential factors.
This study offers crucial theoretical support and practical guidance for field testing and large-scale implementation of abandoned mine thermal storage systems. It provides scientifically reliable technical recommendations for optimizing energy structures and repurposing abandoned mine resources sustainably.
The implications for the energy sector are profound. As countries worldwide grapple with energy crises and the urgent need for improved energy efficiency, Liu’s research presents a viable solution. By transforming abandoned mines into efficient thermal energy storage systems, we can enhance the utilization of renewable energy sources, reduce waste heat, and optimize existing energy supply structures.
Liu’s work is a testament to the power of innovative thinking in addressing complex energy challenges. As we move towards a more sustainable future, the repurposing of abandoned mines for thermal energy storage could play a pivotal role in shaping our energy landscape. This research not only contributes to academic knowledge but also offers practical solutions that could revolutionize the energy sector.