The Role of Plug-in Hybrid Electric Vehicles in Electrifying Personal Transport - Analysis of empirical data from North America

Licentiate thesis, 2020

Plug-in hybrid electric vehicles (PHEV) can help reduce the greenhouse gas emissions in the transport sector, combined with the decarbonization of the electricity sector, and play an important role in electrifying personal transport. This thesis uses empirical data from North America to investigate the role of PHEVs in electrifying personal transport, with a focus on the household context and charging behavior. There is a lack of assessment of electrification at the household level in the literature and Paper I fills this gap by analyzing how household factors impact the share of electrification of vehicle miles travelled (eVMT) considering all vehicles in the household. There is also a lack of empirical studies in the literature analyzing the charging behavior for large samples of PHEV users. Paper II fills this gap with an analysis of a large sample and long observation period for Chevrolet Volt (a long-range PHEV) in North America. To the authors’ best knowledge, it is the first study to map out the range of charging behavior with additional daytime charging and no overnight charging frequencies. Previous studies in the literature have analyzed well-to-wheel greenhouse gas emissions of PHEVs but neglect the effect of charging behavior on tail-pipe emissions. Paper III fills this gap by quantifying the environmental effects of PHEV charging behavior with a focus on tail-pipe emissions of a long-range PHEV such as the Chevrolet Volt.
Our results indicate that PHEVs with a range of at least 35 US miles (56 km) have an important role to play, especially in the electrification of vehicle miles travelled within the household context where they can achieve as much electrification as some battery electric vehicles; regular overnight charging can have a noteworthy reduction on tail pipe emissions of PHEVs and substantially increase share of electrification of miles; and policy for PHEVs should prioritize easy access to overnight charging above public and workplace infrastructure to achieve high shares of electrification.