Life cycle greenhouse gas emissions for last-mile parcel delivery by automated vehicles and robots

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Increased E-commerce and demand for contactless delivery during the COVID-19 pandemic have fueled interest in robotic package delivery. We evaluate life cycle greenhouse gas (GHG) emissions for automated suburban ground delivery systems consisting of a vehicle (last-mile) and a robot (final-50-feet). Small and large cargo vans (125 and 350 cubic feet; V125 and V350) with an internal combustion engine (ICEV) and battery electric (BEV) powertrains were assessed for three delivery scenarios: (i) conventional, humandriven vehicle with human delivery; (ii) partially automated, humandriven vehicle with robot delivery; and (iii) f ully automated, connected automated vehicle (CAV) with robot delivery. The robot’s contribution to life cycle GHG emissions is small (2−6%). Compared to the conventional scenario, full automation results in similar GHG emissions for the V350-ICEV but 10% higher for the V125-BEV. Conventional delivery with a V125-BEV provides the lowest GHG emissions, 167 g CO2e/package, while partially automated delivery with a V350-ICEV generates the most at 486 g CO2e/package. Fuel economy and delivery density are key parameters, and electrification of the vehicle and carbon intensity of the electricity have a large impact. CAV power requirements and efficiency benefits largely offset each other, and automation has a moderate impact on life cycle GHG emissions.

Research Areas: 
last-mile ground delivery
autonomous vehicle
life cycle assessment
greenhouse gas emissions
Publication Type: 
Journal Article
Environmental Science and Technology
Date Published: 
July 30, 2021
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Full Citation: 
Li, Luyao, Xiaoyi He, Gregory A. Keoleian, Hyung Chul Kim, Robert De Kleine, Timothy J. Wallington, Nicholas J. Kemp. (2021) “Life cycle greenhouse gas emissions for last-mile parcel delivery by automated vehicles and robots.” Environmental Science and Technology XX(XX): 1-XX.
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