Optimizing the Use of Electric Vehicles in a Regional Car Rental Fleet

Abstract

The use of battery electric vehicles (BEVs) is increasing in household vehicle fleets and carsharing systems. However, the car rental industry has only timidly adopted this technology. This paper presents a mathematical model for optimal trip assignment of electric and conventional vehicles (CVs) in a regional car rental company. The model was built by using a time–space network, and all BEV charging constraints were part of the formulation. The model needed to satisfy all existing demand, and two objectives were considered: maximizing the number of trips by BEVs and maximizing profit. The model was applied to the Portuguese central region, and the conclusion was that BEVs were considerably less profitable than CVs, because BEVs were less useful for intercity trips. Even if the costs and revenues were the same as for CVs, BEVs were still outperformed by CVs because the recharging time was a drawback in some trips. However, BEVs do not necessarily imply a financial loss for the companies, and a cost–benefit analysis may well prove the existence of considerable profit from including these vehicles, because marketing and environmental effects are not being valued at the moment.