A lifecycle-based sustainability indicator framework for waste-to-energy systems and a proposed metric of sustainability

Studies of waste-to-energy systems have applied a varying range of indicators to assess their sustainability. The sets of indicators prescribed were often based on the respective context and are therefore of varying emphasis. Through a literature review, this research aims to develop a framework of sustainability indicators that can serve as a reference for future research in waste-to-energy systems. Sustainability indicators and their underlying factors from the three pillars of sustainability were consolidated and structured under a proposed framework. As factors interlinking between the three pillars such as carbon schemes are critical for sustainability, they were identified and described within the framework. The proposed framework is extended with a lifecycle dimension to facilitate lifecycle sustainability assessments. This article presents a novel metric of sustainability (MOS). The proposed indicator framework and the MOS are applied in a case study to demonstrate their functions in sustainability assessments. The case highlighted the advantages of the MOS and the importance of considering systems from a more holistic perspective, especially in practice where sustainability issues tend to fall within and across boundaries of the economic, environmental and social lifecycles.