Environmental benefit assessment of vehicle electrification in the fuel cycle: A case study of Chengdu

Abstract

In recent years, vehicle emissions have emerged as one of the most significant sources of air pollutants and CO₂ in Chinese cities. Promoting electric vehicles (EVs) has become a critical strategy for mitigating vehicle-related pollution. While replacing conventional internal combustion engine vehicles (ICEVs) with EVs reduces on-road emissions, the associated increase in electricity consumption and power plant emissions may introduce negative environmental impacts. Overlooking emissions from the upstream fuel production stage can lead to overestimating the benefits of vehicle electrification policies. Therefore, it is essential to comprehensively quantify the environmental effects of electric vehicle promotion policies during the whole fuel cycle. Given that generation emissions are closely tied to the electricity mix, Chengdu (a city with over 85% hydropower) was selected as a pilot city for this study. The research follows a structured approach of ‘emission inventory establishment - air quality simulation - environmental benefit assessment - policy scenario analysis'. We systematically account for fleet emissions in Chengdu over the fuel cycle, simulate pollutant concentrations using the SMOKE-WRF-CMAQ model, estimate premature deaths through the GEMM model with Chinese population distribution data, and evaluate energy-saving and carbon-reduction potentials under various scenarios. The findings reveal that the Electricity Vehicles (EV) scenario reduces annual GHG-100 emissions by nearly 80% compared to the Business As Usual (BAU) scenario, while the Electricity Vehicles with Low-Carbon power grid (EVLC) scenario brings an additional 2.3% reduction. The EV policy significantly reduces PM_2.5, NO_X, and SO₂ concentrations in Chengdu's central urban area but leads to a notable increase in O₃ levels. These differences are further amplified when considering population-weighted concentrations, reflecting fluctuations in population prevalence. Finally, we monetise the impacts of pollutant and greenhouse gas emissions using the Value of a Statistical Life (VSL) and Social Cost of Carbon (SCC), estimating that the promotion of EVs avoids approximately 3913 million yuan in economic losses. These results provide a theoretical foundation and data support for the scientific promotion of vehicle electrification policies and the formulation of low-carbon green development strategies for urban transport in Chengdu.