Connection capacity-constrained energy management for solar- and battery-powered electric bus depots

This paper presents a new sustainable approach to reducing the electricity bills of an electric bus depot through the management of behind-the-meter battery storage systems, considering the connection capacity of the bus depot. To minimize the electricity bills and payback periods of the bus depot in a sustainable way, both the charging and discharging quantities of the batteries are maximized in the proposed model by taking operational constraints, such as available capacities, rate of charge/discharge, electric bus charging, peak power consumption, maximum power import limit, and model degradation, into consideration. In this paper, an algorithm of the proposed model is also provided and validated using real-world profiles under four typical seasons, i.e., summer, autumn, winter, and spring, electric bus fleets, and various battery specifications. The simulation results confirm that the proposed approach can minimize grid import across different seasons, reduce different components of electricity bills that include the time-of-use charge, environmental charge, peak demand charge, and network charge, as well as the total electricity bill, maximize return-on-investment, and minimize payback periods, under diverse electric bus fleets and battery specifications. • Proposing a connection capacity-constrained electricity bill reduction model. • Maximizing battery charging and discharging considering relevant constraints. • Providing a generic algorithm and validating under real-world case studies. • Demonstrating possible ways to reduce battery payback periods.