Product Life Trade-Offs: What If Products Fail Early?

Abstract

Increasing product life allows the embodied emissions in products to be spread across a longer period but can mean that opportunities to improve use-phase efficiency are foregone. In this paper, a model that evaluates this trade-off is presented and used to estimate the optimal product life for a range of metal-intensive products. Two strategies that have potential to save emissions are explored: (1) adding extra embodied emissions to make products more sturdy, increasing product life, and (2) increasing frequency of use, causing early product failure to take advantage of improvements in use-phase efficiency. These strategies are evaluated for two specific case studies (long-life washing machines and more frequent use of vehicles through car clubs) and for a range of embodied and use-phase intensive products under different use-phase improvement rate assumptions. Particular emphasis is placed on the fact that products often fail neither at their design life nor at their optimal life. Policy recommendations are then made regarding the targeting of these strategies according to product characteristics and the timing of typical product failure relative to optimal product life.

The Environmental Impacts of Reuse: A Review

“…(2) Studies that calculate optimum product life spans in order to minimize environmental impacts (E reuse →0 and T 1 does not have to be equal to T 2 in figure ). Studies in this category include Kiatkittipong and colleagues () for electronic goods, Bole () for residential clothes washers, Kim and colleagues () for cars, Kim and colleagues () for fridges, De Kleine and colleagues () for air‐conditioning (AC) units, and Skelton and Allwood () for cars, planes, office buildings, and washing machines. Summarizing the lessons learned from these studies: Should products be reused?…”

Material Services with Both Eyes Wide Open

“…This is because, as Müller et al [130] observe, it is not necessarily the direct annual consumption of a material that provides a service. Where lifetime is unknown, one can estimate it based on physical properties and cultural norms, as discussed in Skelton and Allwood [131]. Where stock provides more than one service, say the rare earth metals contained in a smartphone, one would need to allocate based on the frequency of use per service.…”

Industry 1.61803: the transition to an industry with reduced material demand fit for a low carbon future

“…This allows analysis of the trade-off between maintaining or replacing goods and shows how innovations permeate through the total stock of goods in use. A broad literature reviewed by Skelton & Allwood [35] examines the environmental implications of replacing goods that become more efficient over time due to technical innovation. They find that office blocks and washing machines for example are typically replaced prematurely, whereas cars and planes tend to be kept beyond their environmentally optimal lifespans.…”