Battery storage sizing for a grid tied PV system based on operating cost minimization

An optimal battery storage sizing is determined for a high power photovoltaic (PV) grid tied system. The sizing of the battery storage is chosen based on an optimal power flow management system intended to minimize the system running cost. Thus, a lower level power flow optimization problem is formulated along with the required constraints. The operating cost in this problem is formulated as a combination of electricity grid prices and the battery degradation cost. In the lower optimization level, forecasted system data is used to find the optimal power management solution for a year long operation. On the higher level, a sizing optimization problem is formulated using the outcomes of the lower level optimization while updating it with the new selected battery size. A case study is applied under various conditions to test the system performance and analyze the necessary storage sizing subjected to different circumstances.