The Methodology of Calculating the Optimal ESS Capacity according to PV Power Generation for Grid-Connected PV-ESS System through Optimal Operation

In this study, the method of calculating the Energy Storage System (ESS) capacity according to the amount of photovoltaic (PV) power generation was proposed, to construct a grid-connected PV-ESS system with the best economic efficiency. That is, the model was proposed to calculate the ESS capacity as the cumulative PV power generation amount in the time zone in which 1 h is added to the time of day when the weight of REC is small. To this end, scenarios for each ESS capacity were constructed based on the PV power generation of the system. In addition, a methodology was developed to determine the ESS capacity of the scenario with the minimum payback period as the optimal capacity through the establishment of an optimal operation plan for each scenario.