Assessing electric vehicle policy with region-specific carbon footprints

This study contributes to better understanding the interregional variability in vehicle carbon footprints and presents a case study of China's electric vehicle (EV) charging infrastructure promotion plan (EVSE2020). Based on an integrated hybrid life-cycle assessment (LCA) with new regional electricity mixes and the Thermal Emission Imaging System (THEMIS) model with local inventories, the carbon footprints of battery electric vehicles (BEVs) and internal combustion engine vehicles (ICEVs) are calculated for all size segments. For the A-class segment, the most popular size segment, the results show that the carbon footprint of ICEVs is approximately 250.6 gCO(2)e/km. The BEV carbon footprint under a nationwide electricity mix is 217.6 gCO(2)e/km and ranges between 104.4 (Yunnan) and 265.7 (Shandong) gCO(2)e/km. These results can be explained by the proportion of coal in provincial electricity consumption mixes (10% to 90%). Out of the 31 provinces in mainland China, A-class BEVs driven in 26 provinces will reduce life-cycle greenhouse gas (GHG) emissions compared to ICEVs. In addition, the maximum BEV carbon footprint exceeds the minimum by 79%-121% owing to size segments, which is much higher than that for ICEVs, 59%. The interprovincial variability in vehicle carbon footprints calls for modifications to the interregional priority assignments in the EVSE2020 plan, which currently focuses on air pollution control and economic status. After incorporating explicit considerations of climate mitigation, this study recommends raising the level of priority of three provinces in Central and Southwest China (Sichuan, Chongqing, and Hubei) in the EVSE2020 plan. For provinces with a high share of coal-based electricity, the development of BEVs of small size segments (A00/A0) should be encouraged.