CO2 emissions associated with electric vehicle charging: The impact of electricity generation mix, charging infrastructure availability and vehicle type

With the aim of reducing greenhouse gas emissions associated with the transportation sector, policymakers are supporting a multitude of measures to increase electric vehicle adoption. The actual amount of emissions reduction electric vehicles provide is dependent on when and where drivers charge the vehicles. This analysis contributes to our understanding of the degree to which a particular electricity grid profile, the vehicle type, and charging patterns impact CO₂ emissions from light-duty, plug-in electric vehicles. The authors present an analysis of anticipated emissions resulting from both battery electric and plug-in hybrid electric vehicles for four charging scenarios and five electricity grid profiles. A scenario that allows drivers to charge electric vehicles at the workplace yields the lowest level of emissions for the majority of electricity grid profiles. However, vehicle emissions are shown to be highly dependent on the percentage of fossil fuels in the grid mix, with different vehicle types and charging scenarios resulting in fewer emissions when the carbon intensity of the grid is above a defined level. Restricting charging to off-peak hours results in higher total emissions for all vehicle types, as compared to other charging scenarios.