Impacts of electricity mix, charging profile, and driving behavior on the emissions performance of battery electric vehicles: A Belgian case study

Battery Electric Vehicles (BEV) are considered to be a better alternative for conventional vehicles in the matter of carbon dioxide (CO2) emissions and urban air pollution reduction. Life Cycle Assessment (LCA) is a widely used methodology to quantify and compare the environmental impacts of vehicle technologies. In this study, we compare the life cycle environmental emissions of CO2 equivalent (CO2e), sulfur dioxide (SO2), nitrogen oxides (NOX) and particulate matters (PM) of the BEV with the petrol and diesel vehicles. Unlike many other literatures, this study uses the real-world energy consumption data for the environmental assessment. In addition, this study explores the possible impact of the short term and long term fluctuations in the electricity mix and the vehicle charging profile, on the life cycle emissions performance of BEV. The influence of charging profile on the well-to-tank (WTT) emissions (i.e. emissions associated with electricity production) of BEV is discussed by using hourly emissions and different possible peak and off-peak charging time frames. The results of this study proves off-peak charging is a better option to reduce the life cycle emissions, compared to peak charging. When a BEV is charged during off-peak hours instead of peak hours, the well-to-tank CO2, SO2, NOX and PM emissions per km can be reduced significantly. Also, this study emphasizes the importance of taking driving behaviors of users and auxiliary energy consumption into account. This aspect is analyzed by comparing the empirical energy consumption and the corresponding WTT emissions of BEV, with the New European Driving Cycle (NEDC) standard values. The results reveal that the auxiliary energy consumption is responsible for, nearly a third of the WTT emissions.