With increasing capacity of renewable energy power generation system, energy storage sizing problem raised with growing attention. Optimal energy storage capacity minimizes system cost while ensuring renewable energy meet grid codes. The modified minmax dispatch method has been proved to be one of the superior dispatching methods in wind power integration. In this paper, this dispatching method is applied to photovoltaic grid-connected system, and the corresponding optimal capacity of energy storage system is calculated. Moreover, state of charge (SOC) and depth of discharge (DOD) is considered in the determination of energy storage capacity. Using lifetime cost function as the optimization objective of energy storage capacity. The data of this study are derived from the measured data of the photovoltaic power generation experimental platform in Jinan, China.
Keywords energy storage, sizing, optimization methods, state of charge control, PV–battery integrated energy system