In the heart of China’s coal mining regions, a revolutionary concept is taking shape, promising to transform the way we think about energy storage and renewable integration. Led by Chao Lyu from the College of Energy and Mining Engineering at Xi’an University of Science and Technology, a new approach to thermal energy storage in underground coal mines is gaining traction, with significant implications for the energy sector.
The concept, dubbed “Cemented Backfill Material for Flexible Enhanced Thermal Energy Storage” (CBM–FETES), is not just about storing heat; it’s about creating a symbiotic relationship between coal mines and renewable energy sources. “The core of CBM–FETES is to ensure four essential conditions,” Lyu explains. “These are the suitability of geological conditions, the feasibility of thermal storage and extraction technologies, high efficiency in heat and mass transfer, and the safety and stability of the operational cycle.”
So, how does it work? The idea is to use cemented backfill materials—essentially a mix of coal-based solid waste and cement—to fill the voids left by mining activities. This backfill material serves a dual purpose: it provides structural support to the mine and acts as a medium for thermal energy storage. By integrating this material with advanced heat transfer and extraction technologies, mines can effectively store and release thermal energy, creating a flexible and efficient energy storage system.
The potential commercial impacts for the energy sector are substantial. As renewable energy sources like wind and solar become more prevalent, the need for efficient energy storage solutions grows. CBM–FETES offers a way to integrate these variable energy sources with the existing infrastructure of coal mines, creating a more stable and reliable energy supply. This could lead to significant cost savings and improved energy security for regions heavily reliant on coal.
But the benefits don’t stop at energy storage. The use of coal-based solid waste in the backfill material also addresses environmental concerns. By repurposing this waste, mines can reduce their environmental footprint and contribute to a more sustainable mining practice. “CBM–FETES realizes the full integration of mines and variable energy sources,” Lyu notes, “enriching the connotation of filling mining and providing theoretical references and practical examples for the development of renewable energy in coal mining areas.”
The research, published in Meitan kexue jishu, which translates to Coal Science and Technology, outlines a strategic path for implementing CBM–FETES. This includes pre-mining geological assessments, dynamic parameter responses during mining, and the coupling effect of buried pipes, backfill material, and surrounding rock. The goal is to create a coordinated development of mining underground space and variable energy, ultimately transforming mines into hubs for renewable energy integration.
As the energy sector continues to evolve, innovations like CBM–FETES could play a pivotal role in shaping the future of energy storage and renewable integration. By leveraging the existing infrastructure of coal mines and addressing environmental concerns, this approach offers a unique solution to the challenges of renewable energy adoption. As Lyu and his team continue to refine and implement this concept, the energy sector watches with keen interest, eager to see how this innovative approach could reshape the landscape of energy storage and renewable integration.