Electric Vehicle Route Optimization Under Time-of-Use Electricity Pricing

This paper addresses an electric vehicle routing problem with time window (E-VRPTW) under time-of-use (TOU) pricing where retail prices vary hour-by-hour to reflect changes in wholesale prices. The proposed solution aims to minimize the electricity-cost as well as traditional objectives: number of used vehicles and total travel distance. In particular, the proposed solution cleverly shifts battery charging to off-peak periods and adjusts the charging duration in order to reduce costs. First, the problem is carefully carved in a mixed integer linear programming model. Second, a constraint programming model is built. Third, a combined model is constructed to exploit the strengths of both models. The computational study based on the well-known benchmarking test instances demonstrates we can reduce the electricity cost by 3.1% on average while not compromising other objectives. We provides benchmarking instances and CPLEX source codes, in order to promote related-research, thus expediting the adoption of energy-efficient scheduling by autonomous taxi company.