Evaluation on potential of using abandoned mines for pumped storage in nine provinces of Yellow River Basin

In view of the low utilization rate of closed mine resources and the increasing demand for power and energy storage in China, the pumped storage technology of abandoned mine is an effective means to realize the secondary development and utilization of resources and enhance the peak sheaving capacity of power grid. Based on the working principle and development status of pumped storage power plants using the abandoned mines, it was proposed to build the semi-underground and full-underground pumped storage power plants using the abandoned mines in the nine provinces of Yellow River Basin. By considering the influence factors of space, geology, hydrology, society, economy and resources, an evaluation index system of site selection for pumped storage power plants using the abandoned mine was developed and an case analysis was performed for the pumped storage power plants using abandoned mine in Yellow River Basin. Besides, the development potential of pumped storage power plants using abandoned coal mines in the nine provinces of Yellow River Basin was quantitatively assessed based on the data of abandoned coal mines in the nine provinces of Yellow River Basin from 2016 to 2020 and the calculation methods of static and dynamic benefits of pumped storage power plants using the abandoned mines. The research shows that: (1) Rich energy resources are distributed in the nine provinces in Yellow River Basin and could meet the demand for electricity supply at present, but thermal power is still the main source of electricity supply while hydropower has entered the bottleneck stage of development. (2) The important influencing factors for the site selection of pumped storage power plant using abandoned mine are the special volume of drifts, the water level difference between the upper and lower reservoirs, the stability and permeability of the drift surrounding rocks and the characteristics of groundwater circulation. (3) According to the case analysis on the pumped storage power plant using abandoned mine in Yellow River Basin, it is found that its power generation efficiency could reach 75.7%, which is comparable to that of the conventional pumped storage power plant. (4) The cumulative special volume of shafts and drifts available in the abandoned coal mines in the nine provinces of Yellow River Basin from 2016 to 2020 is 4.7×10⁷ m³. According to the basic information of 132 abandoned mines, it is further estimated from the statistical point of view that the available space of shafts and drifts for the pumped storage power plant in the abandoned mine is 1.34×10⁷ m³, and it is calculated that the annual power generation of the pumped storage power plants using the abandoned mines would reach 3.78×10⁹ kW·h, which could meet the consumption demand for 28.4% of the abandoned wind and photovoltaic power in the nine provinces of Yellow River Basin in 2021, with an annual direct economic benefit of about 2.12 billion yuan. To sum up, the utilization of abandoned mine for pumped storage power plant in the nine provinces of Yellow River Basin has huge prospects of development.