Electric Bus Fleet Management Considering Vehicle-to-Grid Interaction and Solar Energy Production

Environment and health concerns are driving an evergrowing number of large cities to introduce restriction to the circulation of vehicles powered by fossil fuels. Such ordinances inevitably involve public transportation as well, driving an increase in the number of electric bus fleets and their sizes. In planning operation of mass transit, minimization of downtime is a key objective. The large batteries required for mass transportation vehicles and the short time allowed for recharging imply a large power request, which significantly affects the surrounding distribution network. Unidirectional vehicle-to-grid integration of electric bus fleets is helped by the precise time scheduling, giving an advantage over private vehicles integration. The high power required for their recharging operation makes them a suitable storage option to absorb peak solar production during afternoon hours, to reduce the energy wasted because of photovoltaic curtailment. The integration of bus recharging planning with time-dependant photovoltaic production represents an important element for the optimization of electricity production from renewable sources. This article presents a novel methodology which integrates vehicle simulation in scheduling algorithms to optimally integrate bus recharging with electricity generation through non-programmable renewable sources. This approach allows to reduce curtailment by 27.8%, cutting the share of fossil-generated electricity by 27.5%.