大型リチウムイオン蓄電池システムの長期運用実績とその偏劣化に関する実証結果

抄録

Battery energy storage systems (BESS) are expected to be a key technology for achieving carbon neutrality by 2050. This paper presents the results and findings of a nearly 10-year field demonstration of a BESS with lithium-ion batteries starting in July 2013. During the first six years of the demonstration, the basic performance of the BESS was evaluated through normal operations such as load leveling. Subsequently, the BESS was intentionally reconfigured so that the degree of battery degradation in each part was partially different. The authors refer to this state of the BESS as “uneven degradation” in the paper. Since handling the uneven degradation would be an important issue for the BESS operation over long time or when reused batteries are used, the behavior of such unevenly degraded BESS was verified during the remaining demonstration period to understand its characteristics.