Grid-friendly battery electric bus charging and swapping scheduling considering charging infrastructure integrated with photovoltaic and energy storage

The transition to electric public transportation is essential for reducing carbon emissions and fostering sustainable urban mobility. However, the large-scale deployment of battery electric buses (BEBs) poses significant challenges, particularly the increased strain on power grids. To address the issues, this paper proposes a mixed integer linear programming model to optimize the BEB charging and battery swapping schedules, incorporating solar photovoltaic generation and energy storage system. The grid-friendly model supports public transport agencies in addressing a series of real-world complexities, including heterogeneous BEB battery capacities, adjustable charging power levels, various bi-directional energy flow scenarios, and multi-route, multi-depot scheduling. Both capital and operational costs of the charging infrastructure are comprehensively evaluated. Results show that the levelized cost of conductive charging and battery swapping is 1.63 CNY/kWh and 3.88 CNY/kWh, respectively. From an economic perspective, conductive charging is currently more cost-effective. Nevertheless, conductive charging with vehicle-to-grid (V2G) and battery swapping with battery-to-grid (B2G) reduce the net load's peak-valley difference ratio by 9.73 % and 14.84%, respectively. Battery swapping strategy exhibits superior peak load shifting capabilities, contributing to a smoother and more balanced urban load profile.