Learning from assessments of resource efficiency measures and their impact on resource use and the environment - Based on a case of additive manufacturing and a review of assessment studies

Abstract: Resource efficiency measures have the potential to reduce the environmental and resource impacts of the current linear economy by decreasing the physical flows of material and energy associated with producing and using products and services. In order to investigate this potential, there is a need for assessments from a systems perspective, which for example enables the identification of possible trade-offs between different measures and aspects of resource efficiency depending on the product characteristics. The research was carried out in two parts, firstly by synthesising the learnings from a large number of assessment studies. The analysis was built on typologies formulated for mapping resource efficiency measures and product characteristics to the environmental and resource outcomes of the measures in each case. This resulted in a number of findings detailing under which conditions that resource efficiency measures yield environmental and resource benefits, as well as when there are possible trade-offs and limitations. Furthermore, some product characteristics were identified that are key in determining when resource efficiency measures are effective, namely whether products are durable, consumable, complex or whether they have significant impacts from extraction and material production or from their use. Products with significant impacts from the use-phase are called active products and give rise to trade-offs that are discussed in detail, specifically regarding under which conditions there are environmental and resource benefits from extended use or from reducing use-phase impacts. The second part of the research was a life cycle assessment of one such active product, namely 3D-printed truck engines. The aim was to investigate the resource efficiency potential of this emerging technology. Results showed that 3D-printing could lead to net improvements in life cycle impacts, by allowing redesigns of components for lower weight and thus lower fuel consumption. However, the conclusions were only valid under certain conditions, such ascareful material choice and a low-fossil electricity mix for the printing process, without which 3D-printing resulted in environmental deterioration compared to conventional manufacturing. Some results could be generalised to other applications and industries, for example the importance of a low-fossil electricity mix for 3D-printing, which is valid for any application of 3D-printing. In conclusion, useful knowledge on resource efficiency measures was produced both by synthesising many assessment studies and carrying out a single assessment study, especially on the topics of active products and additive manufacturing.