Comprehensive Fleet and Charger Sizing for Public Transportation Electrification Considering Route Assignment

Public transportation electrification is a topic of great interest due to its potentially significant impact on the reduction of greenhouse gas emissions. In order to electrify the public transportation system, the first stage is to determine the appropriate sizing of the necessary assets. Consequently, the goal of this work is the sizing of the fleet and chargers for transit agencies that choose to operate their fleets using overnight charging. The developed methodology incorporates detailed route assignment, energy consumption modeling, and charging requirements for electric fleets. The problem goes through several stages: day-time operation is first modeled for every route individually to determine battery electric bus (BEB) route assignment while enforcing battery state of charge (SOC) constraints. Next, night-time operation is modeled to determine the optimal number of chargers needed to fully charge the fleet in preparation for the next day's operation. The formulation reflects the real-world selection and procurement process, which accounts for the interactions between transit agencies and tech-nology manufacturers or suppliers. In this work the proposed methodology is studied on a transit system composed of four short distance routes, to determine the final number of BEBs and chargers needed. The obtained results show the efficacy of the proposed approach.