Sustainable charging schedule of electric buses in a University Campus: A rolling horizon approach

Abstract

The new juncture of concerns about climate change and finite energy resources has been changing products and processes toward a path of preserving the environment and energy efficiency. Electric mobility along with sustainable charging stations constitutes one way to reduce environmental impacts. However, the coordination of energy resources triggers several challenges that require proper energy management strategies. This work proposes an optimization model to minimize the operational costs of a sustainable charging station (CS) under different charging types for an electric bus, as part of an electric mobility living lab in the public transport system of the University of Campinas (Unicamp, Brazil). The problem is solved using a dynamic approach based on a rolling horizon method that uses as input real data obtained from installed photovoltaic panels and from the operation of an electric bus circulating at Unicamp facilities. The results show that the charging schedule defined by the optimization model is cost effective, reducing the monthly cost by 52% when compared with the actual charging schedule carried out on campus. Furthermore, the inclusion of photovoltaic panels results in a significant reduction in operational costs, which can be enhanced by the inclusion of a battery energy storage system. The results also demonstrate that the operational costs of the CS are not only linked to technical issues, but also to regulatory issues. Then, the proposed optimization model is a flexible tool that allows for the analysis of different charging schedules and the operation of a fleet of electric buses via sustainable charging stations.