Integrated Size and Energy Management Design of Battery Storage to Enhance Grid Integration of Large-Scale PV Power Plants

Battery storage controlled by an energy management system (EMS) becomes an enabling technique to enhance solar farm integration. In this paper, the EMS controls battery storage to shape the fluctuated photovoltaic (PV) plant output into a relatively constant power and support the peak load. The proposed integrated design method considers both battery size and EMS impacts on the utility benefits and cost. The utility benefits include power generation, peak power support, and reduced line losses. The cost of battery storage is determined by the size and lifetime based on the developed battery models. Accordingly, the utility revenue change due to the battery storage controlled by EMS can be evaluated. Therefore, the integrated design of battery size and EMS can be determined by managing the change of utility revenue to gain economic benefits for the large-scale PV power plant application. Finally, the lithium-ion phosphate (LiFePO4) battery and lead-acid battery are compared to demonstrate the proposed method on a utility system model, respectively.