Abstract: In order to make full use of PV(photovoltaic) energy in EV(electric vehicle) charging stations and reduce load peak-valley difference, the energy storage is configured based on the equivalent load power obtained from PV and EV charging power. The energy storage configuration optimization model is established to maximize daily net income of the charging station and to minimize peak-valley ratio with upper and lower limits of equivalent load power as decision variables. The NSGA-II algorithm with the improved genetic cross process is adopted to obtain daily net income of the charging station and the energy storage capacity under different peak-valley ratio. In addition, energy storage capacity configurations under different PV output and charging power levels are compared. The results show that the reasonable PV capacity in a charging station could reduce storage capacity demand. According to the peak-valley ratio, PV and energy storage can be jointly configured to realize the economical operation of the charging station and load optimization.