A study by researchers at the University of Michigan assessed the carbon emissions associated with parcel delivery, finding that whether parcels are delivered by robots or by humans, the emissions are essentially the same; what really matters is the type of vehicle being used.
The coronavirus pandemic has increased the demand for contactless delivery, fueling industry interest in using automation to help deliverers. For example, UPS and Waymo are teaming up to test a self-driving van in Arizona, while Amazon and FedEx are among the companies experimenting with delivery drones. Meanwhile, Royal Mail has been testing the use of delivery drones to reach addresses in the Isles of Scilly.
This University of Michigan study involved examining the environmental impact of advanced parcel delivery scenarios using electric and gasoline-powered autonomous vehicles and two-legged robots to move parcels from delivery hubs to neighbors and then to front doors. These effects were compared to the conventional approach of a human driver delivering packages by hand.
While robots and automation contribute less than 20 percent to a package’s carbon footprint, most of the greenhouse gas emissions come from the vehicle itself. Vehicle powertrains and fuel economy are the main factors determining overall emissions, so switching to electric vehicles and running them on renewable energy sources would have the biggest impact on sustainable parcel delivery, the researchers conclude.
Their study is a life-cycle assessment of cradle-to-grave greenhouse gas emissions for 12 suburban delivery scenarios. Unlike comparable studies, it doesn’t just add up the emissions from the delivery process; it also counts the greenhouse gases released from the production of vehicles and robots and from their disposal or recycling at the end of their working life.
“We found that the energy and carbon footprint of this automated parcel delivery in suburban areas was comparable to that of conventional human-powered vehicles. The benefits of reduced fuel consumption through vehicle automation were outweighed by increased electrical loads from the power requirements of automated vehicles,” said Professor Gregory Keoleian, a civil and environmental expert in Michigan.
“For all delivery systems studied, the use phase of the vehicle is the largest contributor to greenhouse gas emissions, highlighting the need for low-carbon fuels for sustainable parcel delivery. It is critical to decarbonise grids while deploying [EVs].”
The researchers emphasized the importance of the ‘last mile’ – the last part of a package’s journey from a delivery hub to the customer. This is the most expensive, most CO2 intensive and least energy efficient part of the supply chain. Automated last-mile approaches have the potential to reduce overall delivery costs in cities by 10 to 40 percent, although the researchers say their environmental impacts should be explored before being implemented.
Keoleian added that no single automated delivery system is suitable for all situations and that, in addition to environmental performance, other factors such as life cycle costs, safety, visual impact and social sustainability factors such as the impact on employment must also be considered.