Demand for a variety of grocery shopping solutions has grown strongly in recent years, driving the need for environmentally friendly transport. In a new report from Chalmers compares the environmental impact of different ways of delivering chilled grocery bags. The results show that the globally most common solution is not always the best.
When grocery bags are transported between suppliers and customers in European markets, it is usually done in a so-called passive cold chain - the food is kept cold by being placed in a package together with a refrigerant such as ice. Swedish last mile company Gordon has chosen a different solution.
- We use an active cold chain where all our deliveries are made by refrigerated lorries and via refrigerated terminals," says Kristina Liljestrand, Head of Business Development and Expansion.
As Gordon expands into new markets in Europe, it is moving into countries where most potential customers use passive cooling systems.
- "Since all our activities are based on a sustainability perspective, it is important for us to understand how the environmental impact changes when switching to an active cooling system. That's why we commissioned six students from Chalmers University of Technology to analyse the environmental impact of the two systems," says Kristina.
The study compared the cooling methods of 54 European, North American and Australian grocery bag companies. The survey shows that the most common passive cooling method is to transport the goods in a cardboard box with insulation and some form of refrigerant. The four most commonly used types of insulation are cotton, bubble wrap, wool and starch, with either gel packs or ice packs used as the cooling agent. As an alternative to cardboard boxes with insulation, an expanded polystyrene box, also known as an EPS box, is also used together with a refrigerant.
The report, which is the first to compare active and passive refrigeration methods for transporting grocery bags in terms of environmental impact, shows that all passive refrigeration methods generate more CO2 emissions than active refrigeration. Of the passive cooling methods, EPS boxes generate more emissions than corrugated cardboard boxes, and gel packs generate more emissions than ice packs.
The results show that none of the identified passive solutions is better than Gordon's active cooling solution with refrigerated lorries and refrigerated terminals from a carbon dioxide equivalent perspective. Nevertheless, the survey shows that passive solutions are much more common than active solutions in Europe and North America.
- The study can be used by grocery bag companies to compose cooling methods that meet both their own and customers' wishes linked to environmental aspects, and thus strengthen their position in the market. For us, it is proof that our work with an active, unbroken cold chain is the way forward for consistently sustainable deliveries," says Kristina Liljestrand.
Link to the report: https://odr.chalmers.se/handle/20.500.12380/304609
About the study
The report made by students at Chalmers is the first to investigate active and passive cooling methods for the transport of food bags. The purpose of the report has been to describe how the most common cooling methods for last mile deliveries of food bags relate to each other. The cooling methods have then been compared from a carbon dioxide equivalent perspective. The methodology of the study is a mixed method research MMR, a combination of quantitative and qualitative methods, where data has been collected through interviews with suppliers of pre-packed grocery bags and packaging producers, as well as desk research and literature studies.
