Analysis of Influencing Factors of Modification Potential of Abandoned Coal Mine Into Pumped Storage Power Station

Abstract

By modifying underground spaces of abandoned coal mines into underground pumped storage power stations, it can realize the efficient and reasonable utilization of underground space and, at the same time, meet the increasing demand for energy storage facilities of the grid, bringing social, economic, and environmental benefits. Previous research in this area has been limited to the stage of conceptual discussion, and there is no scientific evaluation method for the modification and utilization potential of abandoned coal mine spaces. Establishing a scientific evaluation indicator system forms the basis for evaluating the underground space development and utilization capacity of abandoned mines. Based on the principle of pumped energy storage and the characteristics of coal mine roadway conditions, this paper utilized an analytical hierarchy process (AHP) to evaluate the main influencing factors, including elevation difference between the upper and lower reservoirs, reservoir capacity, roadway surrounding rock stability, and roadway permeability. It analyzed the modification potential of underground spaces and then verified the development potential of the underground spaces of abandoned mines by a statistic model. The study found that the elevation difference between the upper and lower reservoirs is the most influential indicator; second, the capacity of the upper and lower reservoirs is also an important evaluation indicator. The research methods and conclusions will provide useful tools and decision-making basis for analyzing the feasibility and techno-economic benefit of modifying the underground spaces of abandoned coal mines into pumped storage power stations.