Comprehensive Evaluation Method of Energy Storage Capacity Configuration Based on Retired Battery Capacity Degradation Model

The development of the new energy vehicle industry leads to the continuous growth of power battery retirement. Secondary utilization of these retired power batteries in battery energy storage systems (BESS) is critical. This paper proposes a comprehensive evaluation method for the user-side retired battery energy storage capacity configuration. Firstly, the retired battery capacity decline model is studied. Based on the monthly operation optimization results of the BESS, a smaller-resolution battery capacity degradation model is proposed. Subsequently, a multi-objective bi-level optimization model for such comprehensive evaluation of retired battery storage capacity configuration is established, considering multiple indices, such as investment cost, lifetime, net present value (NPV), payback period, and return on investment (ROI). The optimization model is solved by means of the analytic hierarchy process (AHP) and mixed integer linear programming (MILP). Finally, the effectiveness and feasibility of the proposed model and method are verified by the corresponding tests. The test results indicate that the comprehensive evaluation method of energy storage capacity configuration, based on the smaller-resolution retired battery capacity degradation model, can achieve more realistic, technical and economic indices of the BESS, and determine the most suitable scale of energy storage for investment by considering the economy, environmental protection, and technology of the BESS comprehensively.