Interpretation of Manufacturing Sustainability-Assessment Through Hybrid Exergetic and Life-Cycle Metrics

At present, the focus on manufacturing-sustainability is not necessarily on energy management, but rather on its intelligent use. An increase in productivity leads to a reduction in costs, but may increase consumptions based on demand elasticity as rebound effect. The article focuses on exergy coupled with Life Cycle Assessment to address manufacturing-sustainability. Indicators are widely adopted in order to better interpret and communicate the results of a hybrid analysis; they are easy to interpret and represent a useful strategy to quickly and intuitively detect changes in the energy efficiency and quality of processes that are subject to change in time. The aim of this work is to firstly provide an overview on the metrics related to the hybrid or coupled use of exergy and Life Cycle Assessment, their meaning, their practice in particular use cases. The most representative indicators are compared within a real case study and discussion of the results is provided. Among the main outcomes, their accuracy in evaluating environmental but especially on social and economic aspects is not yet clear. The lack of complete and up-to-date data and uncertainty analysis is often problematic, such as the lack of scientific consistency in the interpretation of the assessment.