Lifetime Degradation Study of Batteries Operating as Community Energy Storage Systems

Community Energy Storage Systems (CESSs) represent a new paradigm of distribution systems that integrate batteries to optimize the operation of primary and secondary networks. However, as already seen in electric vehicle industry, determining lifetime degradation of such devices according to their operating profiles is an important question that has to be answered in order to anticipate its technical and economic viability. Thus, this paper presents a study of lifetime degradation in Li-ion batteries operating as CESSs and providing ancillary services in a distribution feeder. The study is based on the Rainflow Counting (RC) algorithm, a method that is used to approximate the number of charging and discharging battery cycles, along with an empirical battery model to predict its degradation. These algorithms are used with two different charging and discharging scenearios for a particular CESS control method. The results show 6% to 13% decrease in service lifetime for a Depth of Discharge (DoD) of 80%, which is consistent with similar studies for CESSs.