Study on the division and calculation of reservoir capacity in tunnel underground reservoirs for pumped storage power stations in abandoned mines (PSPSAM)

• Method for dividing characteristic reservoir capacity in PSPSAM. • Factors influencing storage capacity and estimation methods. • Clarify the challenges of the PSPSAM underground reservoir. • Verify the division method through cases. As countries advance toward low-carbon energy systems, the dual challenge of repurposing abandoned mine resources and addressing the intermittency of renewable energy has gained global attention. The utilization of underground space and water resources within abandoned mines to construct pumped storage power stations represents a promising strategy to extend the post-mining economic value of such sites and enhance the flexibility of new power systems. The accurate compartmentalization and volumetric assessment of subterranean reservoirs present a critical technical hurdle for Pumped Storage Power Stations in Abandoned Mines (PSPSAM), especially when employing roadway networks for underground reservoir construction. Based on a detailed explanation of the technical framework of abandoned mine pumped storage systems and the conventional division of reservoir capacity characteristics, this paper proposes a framework for dividing the characteristic capacity of underground reservoirs in pumped storage tunnels of abandoned mines. The study analyses factors influencing reservoir capacity and explores methods for estimating the capacity of underground reservoirs in these contexts. Critical issues that influence the accuracy of capacity calculation in abandoned mine tunnels are also identified and discussed. This research enhances the understanding of capacity division and estimation in underground reservoirs used for pumped storage in abandoned mines and provides theoretical support and practical guidance for engineering applications.