Multi life cycle assessment: a potential assessment method for product lifespan and environmental performance

Product lifespan is one of key factors for product life cycle environmental performance. Lifespan extending is always considered positive for better life cycle environmental performance. From the view of one product, extended product lifespan can mitigate the environmental performance for avoided new production. But compared with the newer products those with same product function, there may be a tradeoff between lifespan extending and products replacement, because generally the newer products always have the higher energy efficiency and better function. It requires a systematic evaluation method under these circumstances. Multi Life Cycle Assessment (MLCA) may be a potential solution. The system boundary of MLCA is larger, including two or more life cycles of products. The end-of-life options of products, such as components reuse and materials recovery, can be integrated within the system boundary. In this study, MLCA was applied to two types of products, air-conditioner and notebook computer, in China to verify its practicability. The results of MLCA indicated that lifespan extending is better than frequent replacement for the notebook computer in the environmental performance view, for the energy efficiency improvement of notebook improves not so fast. While the MLCA results indicated that products replacement is better for air-conditioners, because the energy efficiency improved fast and evidently. In conclusion, MLCA can be useful for assessment of product lifespan extending point based on the life cycle environmental performance. Further, environmentally friendly technology innovation as an important factor beyond the product itself should be taken into consideration for optimal product lifespan assessment.