Materials Systems Laboratory , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , United States.
Research and Innovation Center , Ford Motor Company , Dearborn , Michigan 48121 , United States.
Environ Sci Technol. 2019 Sep 17;53(18):10560-10570. doi: 10.1021/acs.est.9b00648. Epub 2019 Aug 26.
Electrification and lightweighting technologies are important components of greenhouse gas (GHG) emission reduction strategies for light-duty vehicles. Assessments of GHG emissions from light-duty vehicles should take a cradle-to-grave life cycle perspective and capture important regional effects. We report the first regionally explicit (county-level) life cycle assessment of the use of lightweighting and electrification for light-duty vehicles in the U.S. Regional differences in climate, electric grid burdens, and driving patterns compound to produce significant regional heterogeneity in the GHG benefits of electrification. We show that lightweighting further accentuates these regional differences. In fact, for the midsized cars considered in our analysis, model results suggest that aluminum lightweight vehicles with a combustion engine would have similar emissions to hybrid electric vehicles (HEVs) in about 25% of the counties in the US and lower than battery electric vehicles (BEVs) in 20% of counties. The results highlight the need for a portfolio of fuel efficient offerings to recognize the heterogeneity of regional climate, electric grid burdens, and driving patterns.
电气化和轻量化技术是轻型车减少温室气体 (GHG) 排放策略的重要组成部分。对轻型车温室气体排放的评估应采用从摇篮到坟墓的生命周期视角，并捕捉重要的区域影响。我们报告了美国首次对轻型车轻量化和电气化使用进行的区域明确（县一级）的生命周期评估。气候、电网负担和驾驶模式的区域差异叠加在一起，导致电气化的温室气体效益在区域上存在显著的异质性。我们表明，轻量化进一步加剧了这些区域差异。事实上，就我们分析中的中型汽车而言，模型结果表明，装有内燃机的铝制轻量化汽车在全美约 25%的县的排放量与混合动力电动汽车 (HEV) 相当，而在 20%的县的排放量低于电池电动汽车 (BEV)。研究结果强调需要采用一系列节能产品，以认识到区域气候、电网负担和驾驶模式的异质性。
