Petra Stock
Along with their cult following on social media, autonomous delivery robots travelling on footpaths could be the most climate-friendly way to do your grocery shopping.
Around the world, COVID-19 has seen a change in the way people shop for groceries. Instead of driving to the supermarket more people are ordering online for pick-up or home delivery, and even in some places, delivery by drone or robot.
In the United States supermarket home delivery services grew 54% between 2019 and 2020. In Australia, Woolworths and Coles experienced unprecedented demand.
The rapid growth in e-commerce has seen an increased focus on the greenhouse gas emissions associated with the ‘last-mile’ delivery.
A study by University of Michigan researchers and the Ford Motor Co modelled the emissions associated with the journey of a 36-item grocery basket from shop to home via a number of alternative transport options. Their study is published in the journal Environmental Science & Technology.
“This research lays the groundwork for understanding the impact of e-commerce on greenhouse gas emissions produced by the grocery supply chain,” says the study’s senior author Greg Keoleian, director of the Center for Sustainable Systems at the University of Michigan.
The researchers modelled 72 different ways the groceries could travel from the warehouse to the customer. Across all options, the results showed ‘last-mile’ transport emissions to be the major source of supply chain emissions.
They found the conventional option of driving to the supermarket in a petrol or diesel car to be the most polluting, creating six kilograms of carbon dioxide (CO2). All other choices had lower emissions, with footpath delivery robots the cleanest for the climate, at one kg CO2.
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A customer who switched to an electric vehicle could halve their emissions. But they could achieve a similar impact on emissions by reducing their shopping frequency. Without buying a new car, households who halved the frequency of supermarket trips reduced emissions by 44%.
Keoleian says the study emphasises the “important role consumers can serve in reducing emissions through the use of trip chaining and by making carefully planned grocery orders.” Trip chaining refers to combining grocery shopping with other errands.
All home delivery options had lower emissions than in-store shopping – in part due to the efficiencies gained in store operation and transport – with the potential to cut emissions by 22 – 65%.
Footpath robots are being trialled in cities across the United States, Europe and China. These four or six wheeled robots carry items like supermarket shopping or retail items over short distances. Most have a delivery range around three kilometres.
Starship robots is one example. Since launching in 2014, their robots have completed three million autonomous home deliveries in cities across Estonia, the United Kingdom, Finland and the United States.