Slope Stability Challenges in Repurposing Abandoned Coal Mine Pit for Hybrid Pump Hydropower Storage

The transition towards renewable energy sources has led to a growing need for effective energy storage systems to ensure a stable and reliable power supply. Solar and wind power, although abundant, are intermittent, causing fluctuations in electricity generation. To mitigate this issue, energy storage solutions are required to store surplus energy during periods of low demand and release it during times of high demand. This research focuses on repurposing abandoned open pit coal mines as Hybrid Pump Hydropower Storage (HPHS) systems, where the mine pit functions as the lower reservoir.

The stability of the slopes in these repurposed mines is a critical factor for the successful implementation of HPHS. The presence of water in the lower reservoir and the potential inflow of groundwater play significant roles in determining slope stability. An analytical and numerical model has been developed to assess the slope stability in the selected mines for HPHS operations. Various factors, including fluctuating groundwater levels, reservoir filling levels, and different loading conditions, have been considered in the analysis.

The findings of this study contribute to a better understanding of the impact of these factors on slope stability in HPHS applications.