Optimal planning method for the high-quality coal mine energy system with complete clean energy supply

Under the “30·60” dual carbon goals, the transit to a green, cost-effective, and efficient energy utilization approach in coal mining areas has become an urgent need for China’s energy revolution. Western mining areas in China are endowed with abundant renewable energy resources while facing the challenges in on-site renewable energy consumption, high investment costs and low utilization rates for electrical equipment, and limited transmission capacity. To enhance the cleanliness of energy utilization in mining areas, improve the stability and reliability of energy supply, and strengthen the ability of mining areas to support the external power grid, a high-quality coal mine energy system (HCMES) with complete clean energy supply and the corresponding planning method are proposed respectively. Firstly, a comprehensive clean energy HCMES framework is developed con-sidering the load characteristics and associated energy utilization in western mining areas, and combining renewa-ble energy generation with pumped-hydro storage in abandoned mine. Secondly, taking into account the demand response capability of the entire production process in mining areas and considering the energy balance con-straints of the system, the HCMES planning model is proposed to completely utilize the clean energy supply. Finally, with the objective function of minimizing the annual average comprehensive cost of the system, the original problem is reformulated into a mixed integer linear programming model to solve the optimal configuration for the high-quality coal mine energy system. Using real data from a western mining area in China with annual coal production of 12 million tons in a certain year, this study validates the effectiveness of the proposed model and methodology. Additionally, the impact of the uncertainty in renewable energy output and production load demand on the optimization results is analyzed. The simulation scenarios include four different configurations of the mining area energy system: system without energy storage, system with pumped-hydro storage, system with electrochemical storage, and system with pumped-hydro storage (without external electricity purchase). The results indicate that the proposed HCMES can reduce electrical primary equipment investment by 11.11% compared to other configurations, achieve a 7.91% reduction in the average annual comprehensive cost compared to Configuration 3, and potentially decrease the total carbon dioxide emissions from energy consumption in the mining area by up to 91.17%. The HCMES, by fully consuming on-site renewable energy and achieving complete clean energy supply for mining area production, while maintaining sufficient reserve capacity, can export flexible, stable, and controllable electrical energy under medium and long-term power contracts. This approach offers significant economic, environmental, and social benefits.