Active Control Strategy of Energy Storage System for Reducing Maximum Demand Charges under Limited Storage Capacity

Abstract

Commercial and industrial customers are subject to monthly maximum demand charges, which can be as high as 30% of the total electricity bill. A battery-based energy storage system (BESS) can be used to reduce the monthly maximum demand charges. A number of control strategies have been developed for the BESS to reduce the daily peak demands. However, the existing control strategies may fail to reduce the peaks on some occasions because the energy of the BESS runs out during the process of peak reduction. Therefore, a new active control strategy for the BESS is developed and presented in this paper. This strategy is able to reduce the peaks even though the peaks are different from the forecasted ones. This strategy is able to reduce the monthly maximum demands by 9% when the BESS capacity is reduced to 37% of the full capacity due to financial constraints. Hence, the customers can achieve the payback period of 11 years over the project lifespan of 21 years with the reduced capacity of the BESS.