Energy savings and emission reduction benefits of China's aluminum use paths in transport sector

Amid global climate change concerns, China, as the world's largest carbon emitter, confronts significant challenges in energy conservation and emission reduction aligned with its "dual carbon" objectives of achieving peak carbon emissions and carbon neutrality. Focusing on the transportation sector, this study employs the life cycle assessment (LCA) method and GREET software to analyze energy consumption and emissions across fuel vehicles (ICEVs), battery electric vehicles (BEVs), and plug-in hybrid vehicles (PHEVs) under varying lightweighting scenarios. The results show that the energy savings and emission reduction effect are best when the lightweighting ratio is 40 %, with a significant decrease in carbon emission and energy consumption, and the reduction in the vehicle's carbon emissions is approximately 5.93 % to 9.47 %, and the savings of the comprehensive energy consumption are 6.6 % to 7.75 %. The lightweighting scenario of 25 % shows the same trend of decreasing carbon emissions and energy consumption, but the effect is lower than the 40 % lightweighting scenario. However, in the lightweighting ratio scenarios of 55 % and 70 %, the advantage of the vehicle's use phase cannot offset the penalty of the aluminum production phase, and as the lightweighting ratio increases, energy consumption and carbon emissions also increase. A characterization of the environmental impacts over the entire life cycle of vehicles reveals that the global warming potential (GWP) is the highest. As the share of thermal power generation in the electricity mix decreases, it leads to a reduction in carbon emissions from aluminum production, and reduces the carbon penalty associated with a greater proportion of lightweight vehicles. This study provides a reference for China's aluminum application strategy in the transport sector.