Design Algorithm for Optimum Capacity of ESS Connected With PVs Under the RPS Program

A distributed power generation system uses an intermittent power source that provides low power. Furthermore, it cannot be centrally controlled from the perspective of the system operator. The photovoltaic (PV) power generation system is installed with an energy storage system (ESS) to increase the power source quality compared to that possible with PV-only power generation. In this paper, an estimation algorithm is proposed for improving battery capacity to construct a suitable and economical system. In addition, an optimal algorithm is proposed that considers different factors. For example, the cost of constructing the battery and the amount of electric power sales reflecting the renewable energy certificate weighting factor of 5.0 are based on the cost of the battery construction, depth of battery discharge, charge/discharge cycle of the battery, cost of the energy conversion device, operation maintenance cost, and charge cycle of the battery. The optimized battery capacity is calculated by considering the correlation between PV power and meteorological parameters, construction cost, and the benefit of the amount of electricity sold, with an error rate of 5.75%.