Flexible Integrated Network Planning Considering Echelon Utilization of Second Life of Used Electric Vehicle Batteries

Abstract

The echelon utilization of retired batteries has attracted more attention as the market share of electric vehicles (EVs) increases steadily year by year. The current battery recycling methods cannot utilize the remaining value of these retired batteries effectively. Studies have shown that second-life batteries (SLBs) have a much lower cost compared to fresh batteries but retain a certain capacity simultaneously, which means that they have a high secondary utilization value. Therefore, this article proposes a novel multistage system planning model, including battery energy storage system (BESS). BESS designed in this article involves not only the use of fresh batteries but also the echelon utilization of SLBs and considers the multiple lifespan cycles based on its state of health (SOH). Moreover, the proposed planning strategy integrates the electricity and transportation networks in the first stage and evaluates the flexibility of the planning system by comparing the adaptation costs of each system in the second stage. The proposed planning model is verified on the IEEE 33-bus electricity system and the 20-node transportation system. According to the simulation results, the differences in system cost and system operation situations caused by fresh batteries and SLBs are analyzed, verifying the effectiveness and flexibility of echelon utilization of SLBs.