Optimal Scheduling for Dispatchable Utility-Scale Solar PV Power with Battery-Supercapacitor Hybrid Energy Storage System

The optimal scheduling for dispatchable utility-scale solar PV power with a hybrid energy storage system consisting of a battery and a supercapacitor (SC) is investigated in this paper. The optimal capacity of the energy storage system (ESS) is assessed based on its usage of depth of discharge, which is critical for minimizing the cost of a dispatchable PV power scheme. The hybrid system can successfully dispatch the scheduled power at any dispatching horizon by leveraging the optimal ESS capacity. Both cycling and calendar expenses are taken into account during the cost optimization of the ESS to make it more practical. Furthermore, a state of charge (SOC) control technique based on a fuzzy inference system that takes into account both battery and SC SOC is used to accurately estimate the grid reference power for each dispatching horizon considered in this study.