Simulating the service lifetimes and storage phases of consumer electronics in Europe with a cascade stock and flow model

Durability of products and lifetime extension through improvements in product design, repair, reuse and refurbishment are integral components of the circular economy concept. Extended service lifetimes reduce the demand for new resource intensive products and hence contribute to an increase in resource efficiency and resource conservation. However, the use of a consumer product does not only depend on its functioning. Particularly consumer electronics such as smartphones are often only used for comparatively short periods of time before they are replaced by new devices. Even though these used electronics may still have significant value and could be resold as secondhand products, they often remain in households (compartments, shelves, cellars) for long periods of time. When analyzing the effects of technical improvements for lifetime extensions of consumer products, these storage times, which are also referred to as hibernation, need to be taken into account. Hibernation counteracts efforts towards increasing the service lifetimes of consumer electronics and should therefore more strongly be addressed in the discussion about lifetime extension and higher durability. In this paper, we present a dynamic cascade stock and flow model to simulate different use and storage phases of consumer electronics in Europe. This model enables a detailed analysis of modifications in service lifetimes and storage phases. The simulation results emphasize the significant proportion of unused but functioning electronic devices when regarding overall product stocks in society. Based on the simulation results, we show that particularly for small consumer electronics such as smartphones, the systematic implementation of a cascade use system avoiding storage phases could significantly reduce total product demand and the associated resource use. Subsequently, we discuss potential measures that could lead to a reduction of storage time of unused consumer electronics in typical households.