Energy and environmental characterization of operational modes of plug-in vehicles

This paper presents an energy and environmental characterization of the two most relevant Plug-in Hybrid Electric Vehicles available in the market (Opel Ampera and Toyota Prius Plug-in), in order to provide an estimate of fuel and electricity consumption, tailpipe emissions and charge depleting mode mileage for any drive cycle studied, based on vehicle specific power methodology. These vehicles were monitored under real-world operation with a portable laboratory that collects data from vehicle sensors (via on-board diagnosis port), exhaust gas composition and GPS in a second-by-second basis. An indirect method to measure battery energy fluxes and consequently estimating electric range was developed, providing maximum errors for the Charge Depleting driving range of 4.2% for the Toyota Prius Plug-in and -0.2% for the Opel, when comparing with measured data. Regarding fuel consumption, the maximum error verified was of -4.1%. Using two driving profiles measured in Portugal and the USA, the performance of the two vehicles under charge depleting (CD) and charge sustaining (CS) conditions was compared. Major findings indicate that Opel Ampera is more efficient in CD mode, while the Prius Plug-In is more efficient under CS conditions, but highly dependent on driving behavior when in CD mode.