UC Davis Institute of Transportation Studies

Will people recharge a vehicle that does not have to be recharged? This, and the degree to which plug-in hybrid electric vehicle (PHEV) designs emphasize gasoline or electricity, are central to assessing the energy and environmental effects of PHEVs. Plug-in conversions of hybrid vehicles are being made available to (predominately new-car buying) households throughout the Sacramento region for four to six weeks each. The vehicles are instrumented to report travel and energy; households are interviewed and surveyed. Results from the first 34 households—all selected in part because they can recharge a vehicle at home—indicate that on average they will recharge a PHEV about once per day, but with wide variation across households. The PHEV designs created by these households emphasize increased fuel economy rather than all-electric operation—as did the designs of prior representative samples of new-car buyers (who had not driven PHEVs). This result may be due in part to 1) “anchoring” (respondents are driving a PHEV that does not practically allow all-electric operation), and 2) households not creating integrated assessments of gasoline and electricity use/cost from the in-vehicle and internet-based instrumentation. Over the PHEV trials, narratives are co-authored about the PHEVs and their place in the ongoing life-stories of the participants. The primary themes to emerge are changing driving behavior, recharging habits and etiquette, confusion about PHEVs and how they work, and the role of payback analyses and more intuitive assessments of whether PHEVs are “worth it.” Tracing social interactions by the participants about the PHEVs reveals that complex translation of ideas and information about PHEVs is occurring as the PHEV drivers, in particular, use their trial period to reflexively explore lifestyle and identity possibilities of these new vehicles.