Abstract

Based on necessary literature review, LC (Life Cycle) emissions, in particular LCCO2 (Life Cycle CO2) emissions, of BEVs (Battery Electric Vehicles) have been assessed and compared with the most efficient ICEVs (Internal Combustion Engine Vehicles), such as non-plug-in HEVs (Hybrid Electric Vehicles) and diesel cars. By considering CO2 emissions from vehicle production, vehicle recycle and the entire process of energy flow (from the mining of the energy source to a vehicle being driven), LCCO2 emission models of BEVs and ICEVs were built. For comparing between BEVs and ICEVs in terms of their LC emissions, a new measure named SRPR (Square Root of Power and Range) has been proposed for correctly reflecting the powertrain’s main performance. Results show that, although BEVs have much lower ECR (Energy Consumption Rate) than non-plug-in HEV and diesel cars, their LCCO2 are very variable, and are very dependent on LCCO2 of power generation mix of specific country. In some countries where thermal power generation, in particular coal power generation, is still dominant, BEVs’ LCCO2 are apparently higher than ICEVs. If a country would like to have their BEVs operating lower LCCO2 than ICEVs, the overall average LCCO2 from their power generation mix should be at least at the level about 320 g/kWh. As a case study, by analysing the power generation development trend and the BEV development trend in China, it suggests that their aim for developing BEVs to have lower LCCO2 than ICEVs in next two or three decades would be very difficult to meet. If they like to put priority on the reduction of LCCO2 of ground vehicles, BEVs could not be widely promoted in China until they made their power generation clean enough, probably at least in next 20 even 30 years. Finally, BEVs’ other LC pollutant emissions, such as NOx (Nitrogen Oxides), PM (Particulate Matters), SOx (Sulfur Oxides) would not be a very serious problem if those thermal power generations are equipped with adequate exhaust aftertreatment for removing those pollutant emissions.