Abstract:

Electric vehicles (EVs) have been promoted acceleratively to reduce greenhouse gas (GHG) emissions; however, the GHG emission reduction potential of different powertrain EVs has not been investigated thoroughly. In this study, the authors firstly quantified and compared the GHG emissions of different powertrain vehicles in a life cycle perspective with a particular focus on energy and climate consequences for current and future integrated scenarios to facilitate carbon reduction assessment for Shanghai. Four major types of EVs were considered. The results show that life cycle total energy consumption and GHG emissions of all EVs are lower than that of gasoline internal combustion engine vehicles (GICEVs), among which battery-powered electric vehicles (BEVs) are the lowest. Compared with GICEVs, the total energy use and GHG emissions of BEVs decreased by 34.2% and 41.7%, respectively. As the electrification of vehicle powertrain systems innovates, the life cycle emissions of GHG are gradually concentrated in the upstream stage. The sensitivity analysis demonstrates that vehicle life cycle GHG emissions are more sensitive to the proportion of thermal power than the other three parameters (utilization rate of recycled steel, vehicle lifetime, and curb weight). The scenario analysis indicates that BEVs present a more favorable carbon emission decline performance over other EVs from a long-term perspective. It is estimated that up to 12.5 million tons of GHG emissions could be reduced under the optimistic scenario in 2050 in Shanghai. In the process of energy conversion from oil to electricity in transport in Shanghai, BEVs should be constantly promoted.