Obstacle identification for the development of pumped hydro storage using abandoned mines: A novel multi-stage analysis framework

Abstract

To achieve the ambitious goals of "emission peak" and "carbon neutrality", China has developed a large number of wind and solar power plants. Access to a high percentage of renewable energy brings great challenges to the stability and flexibility of the power system. Pumped hydro energy storage (PHES) is a proven and economical technology to regulate the peak load and frequency. The development of pumped storage power plants using abandoned mines not only facilitates the effective use of underground space, ecological restoration and local resettlement of workers, but also promotes the large-scale use of renewable energy sources such as wind and light energy. However, in China, this technology is still at the conceptual stage, with few actual cases. Relevant studies have not comprehensively analyzed the obstacle factors faced by PHES and the relationship between them. Based on this, the paper sorts out the relevant obstacle factors from five aspects (economy, technology, construction, geography, and society), combines and improves the Decision-making Trial and Evaluation Laboratory (DEMATEL) and Interpretative Structural Modeling (ISM) methods, constructs an obstacle analysis framework, and explores the influence relationships among obstacle factors. Six key obstacle factors are obtained in this study: uncertain initial capital cost (E1), poor tightness and stability of surrounding rock (T3), construction difficulties (C2), water source problem (G1), insufficient policy drivers (S1), and the lake of demonstration projects (S2). The time-series analysis shows that the effects of E1 and S1 will diminish after 10 years. From the topological hierarchy diagram, it can be found that the impact of transportation problem (C1) will be weakened, and the impact of C2 and S2 on S1 will no longer be obvious with the gradual improvement of the policies. The sensitivity analysis shows that the model constructed in this study is robust and less influenced by the expert knowledge background. In the future, the government should promote the construction of underground PHES by encouraging enterprises’ capital investment, promoting key technology research, establishing information sharing database, and setting up demonstration projects. This study enriches the theory of PHES development in abandoned mines and provides guidance and theoretical basis for future engineering practice.