Optimal electric bus scheduling by considering photovoltaic charging infrastructure

Battery electric buses (BEBs) are introduced to substitute for diesel buses worldwide owing to their zero emissions. Investigating BEB scheduling problems is crucial for minimizing charging costs and satisfying passenger demands. In addition, photovoltaic and energy storage system (PESS) adoption on public transport could offer a promising alternative toward reducing charging cost and carbon emissions. This paper presents a novel BEB scheduling problem in which PESS is deployed at bus charging stations. The proposed problem is formulated as a mixed-integer linear programming in which BEB scheduling and photovoltaic (PV) energy scheduling are optimized. To improve solution efficiency, a two-step solution approach is proposed. First, a BEB scheduling problem without considering PESS is solved in the first step, and then a PV energy scheduling problem is solved in the second step. A case study is performed using the operational data of bus No. 404 and 109 in Beijing. Results show that the sum of charging and carbon emission costs will be reduced considerably if PESS is introduced in a transit system. This study provides new insights for engineering a sustainable future in green transportation.