Optimal Energy Storage System Planning for Microgrids with Contract Capacity Constraint

Due to the inherent variability of Renewable Energy Generation Systems (REGSs), REGSs are commonly uncontrollable. Although microgrids can effectively monitor REGSs, it cannot directly manage and control the intermittent output characteristic of REGSs. Recently, many experts recommend that Energy Storage Systems (ESSs) should be integrated into REGSs to mitigate the instability and further reduce the peak load and contract capacity of microgrids. Although the benefits of ESSs for REGS integrations are significant, their benefits greatly depend on the locations and capacities of ESSs installed. Therefore, this paper proposes an optimal capacity planning for ESS to reduce contract capacity of microgrids. The optimal charging/discharging scheduling of ESSs can also be obtained by the proposed method. An actual microgrid with field measurements is used to test the proposed optimal ESS capacity planning method. Test results demonstrate the validity of the proposed method. Keywords: Renewable Energy Generation System, Microgrid, Energy Storage System, Contract Capacity, Optimal Capacity Planning.