To accurately predict the life-cycle carbon reduction benefits of replacing a diesel heavy-duty truck with an electric one, taking a single heavy-duty truck as the object, the variation trend in electric and diesel carbon emission factors from 2023 to 2050 were predicted; coupled with the life spans and life-cycle mileage of the two types of heavy-duty trucks, a dynamic carbon emission model for the heavy-duty trucks was constructed in stages. The carbon footprints of the trucks under the "Net Zero Emissions by 2050 Scenario (NZE)", "Announced Pledges Scenario (APS)", and "Stated Policies Scenario (STEPS)" were analyzed. In addition, the carbon reduction and carbon reduction rate were calculated. The results showed that battery manufacturing and battery recycling were the main factors to impair the improvement of carbon reduction in the production and recycling stages of electric heavy-duty trucks, respectively. For every 1 g·(kW·h)-1 reduction in the electricity carbon emission factor (CO2), an electric heavy-duty truck could reduce 1.74 t of carbon emissions over its life cycle. Under the three scenarios, the carbon emissions during the operation stage of both types of heavy trucks accounted for more than 90% of the total life-cycle carbon emissions. Carbon reduction benefits from the highest to the lowest were NZE, APS, and STEPS, and their corresponding life-cycle carbon emission reductions were 1054.68, 1021.78, and 1007.97 t, with carbon reduction rates of 54.38%, 52.68%, and 51.97%, respectively.
Keywords: carbon emission; carbon emission factor; dynamic model; heavy-duty truck; life cycle; scenario analysis.