Plug-in hybrid electric vehicle utility factor in China cities: Influencing factors, empirical research, and energy and environmental application

Promoting Plug-in Hybrid Electric Vehicles (PHEVs) is a promising strategy to mitigate the climate change and improve the environment in the road transportation sector. To evaluate the complex energy saving and GHG emission reduction contribution of on-board fuel and electricity, utility factor (UF) is the most widely adopted parameter to weight the distance driven by electricity and on-board fuel, respectively. However, few researches focus on city-level actual utility factors based on quantitative analysis of the influencing factors, especially in China. In this research, a probability-distribution-based PHEV UF function is constructed from travel pattern parameters, charging frequency and PHEV charge depleting range. Then the urban city-level UF at actual travel and charging patterns are derived from PHEV driving big data in seven typical cities in China. The sales-weighted actual UF is 0.49 and 0.64 for a 50 km-electric-range PHEV and a 80 km-electric-range PHEV; therefore, PHEVs with over 80 km electric range are recommended in China urban areas due to better energy saving and emission reduction potential. Finally, carbon and pollutant emissions are analyzed, actual PHEV carbon emission is 133–137 g/km currently while it could drop to 71–88 g/km at a grid with 80% renewable energy; therefore, cleaner grid would largely contribute to PHEV environmental effects.