Developing an hourly-resolution well-to-wheel carbon dioxide emission inventory of electric vehicles

Vehicle electrification is reshaping global road transport, whereas the understanding of the well-to-wheel (WTW) CO2 emissions of electric vehicles (EVs) is mostly limited to the annual average, ignoring short-term variation. This study developed a framework to quantify the heterogeneity in the WTW CO2 emissions of EVs with different charging hours for multiple regions. The framework incorporates the consumption-based grid's CO2 emission factor, dynamic EV fuel consumption rate, and different charging levels and EV types. A three-year hourlyresolution WTW CO2 emission inventory of EVs was established for 71 regions across the contiguous United States. Results show that the EV's WTW CO2 emissions vary by season, charging hour, region, and EV type; up to 26% of WTW CO2 emissions could be reduced by shifting the current most common charging time. The study built a foundation inventory for policymakers to formulate daily smart charging schemes to minimize EV's WTW CO2 emissions.

Automated summary

Vehicle electrification is transforming global road transport, but the understanding of electric vehicle's (EVs) well-to-wheel (WTW) CO2 emissions is limited to annual averages, disregarding short-term variations. This study developed a framework to quantify the heterogeneity in WTW CO2 emissions of EVs based on different charging hours and multiple regions. By considering consumption-based grid CO2 emission factors, dynamic EV fuel consumption rates, and different charging levels and EV types, a three-year hourly-resolution WTW CO2 emission inventory was created for 71 regions across the contiguous United States. Results showed that EV's WTW CO2 emissions vary based on season, charging hour, region, and EV type, with a potential reduction of up to 26% by shifting the common charging time. This study provides a foundation for policymakers to develop smart charging schemes to minimize EV's WTW CO2 emissions.