Energy storage planning for a rooftop PV system considering energy sharing

This article proposes a battery energy storage (BES) planning model for the rooftop photovoltaic (PV) system in an energy building cluster. One innovative contribution is that a energy sharing mechanism is integrated with the BES planning model to study cooperative benefits between the PV owner and users, and meanwhile facilitate the reasonable installation of BES. In particular, the conditional value-at-risk (CVaR) is introduced to characterize the individual risk-preference degree of users against the uncertainties of electricity price. To enhance the computation efficiency and capture the interaction between the PV owner and users, the original problem is decomposed into a major energy trading problem and an additional payment bargaining problem. Specifically, the energy trading problem is solved by a distributed way to find the optimal BES sizing and energy sharing profiles; while an effective analytical method is derived to determine the associated payment scheme. Case studies verify the feasibility and effectiveness of the proposed model. The simulation results indicate that the cooperation operation increases revenues for the PV owner, decreases costs for users, and reduces the peak-to-valley difference of system load. The optimal sizing of BES is mainly affected by the scale of PV generation and the energy trading mode. In addition, it is proved that the proposed algorithm can effectively obtain the global optimal solution.