MCDA for the sustainability assessment of energy technologies and systems: identifying challenges and opportunities

Kurzfassung

Abstract Background Sustainability assessment comprises many different forms of assessment—from Life Cycle Sustainability Assessment to freely chosen indicator assessments—often yielding contradictory results. Multi‑criteria decision‑analysis (MCDA) methods have been recognized as a powerful and frequently applied tool to support decision‑making in the field of energy. This study analyzes the application of MCDA in the sustainability assessment of energy technologies and systems within the Helmholtz Association, a network of German research centers addressing important topics ranging from cancer research to polar science. Energy technologies are a key focus of research within several Helmholtz research centers. Based on 20 case studies performed by Helmholtz researchers, we identify trends, challenges, and opportunities in criteria selection, MCDA method application, and stakeholder engagement. Results The selection of criteria and indicators often reflects the triple bottom line framework, with a strong emphasis on environmental and economic dimensions, while social criteria receive little attention due to methodological gaps. For indicator aggregation, there were three preferred methods: the Weighted Sum Method (WSM), the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) for compensatory studies due to its ease of application and simplicity, and the Preference Ranking Organization METHod for Enrichment Evaluation (PROMETHEE) due to its non‑compensatory attributes, consistent with the principles of strong sustainability. However, inconsistencies in weight elicitation methods, with frequent misalignment between the chosen methods and underlying MCDA principles, were found in the analyzed studies. The integration of stakeholders remains underutilized, with most studies involving experts but lacking broader societal involvement. Participatory techniques such as workshops and surveys are mainly applied for criteria weighting, but their implementation across all MCDA stages remains limited. Analysis of group decision‑making approaches indicates a predominance of input‑level aggregation, with few studies exploring comparative or output‑level techniques. Conclusions This paper highlights the need for methodological advancements in social sustainability assessments and more robust stakeholder engagement strategies. In addition, further education on MCDA methods is needed to bridge the knowledge gaps of practitioners. By comparing Helmholtz MCDA practices with best practices from other research, this work aims to strengthen the sustainability assessment of energy technologies and systems.