ISD: A New Methodological Approach for Measuring the Sustainability of the German Energy System

The research community has developed three main concepts and indicator systems to measure sustainability: the capital concept, the ecological concept and the multidimensional concept. Whereas a lot of research has been dedicated to the pros and cons of the three/four-pillar sustainability concept, to the shaping of the pillars and their indicators, research on standardized methods to aggregate the indicators to one index is lacking. However, a useful model exists—the GDP—which summarizes the different economic activities of various social actors in one index. An overall sustainability index has the advantage that the sustainability of a system can be expressed in one index. This allows the sustainability status of a system to be better communicated both to the public and to politicians. Against this background, we developed the Index of Sustainable Development (ISD) to measure the sustainability of systems described by multidimensional sustainability concepts. We demonstrate that it is possible to aggregate sustainability indicators of the multidimensional sustainability concepts to one index. We have chosen exemplarily the German sustainability strategy and selected the energy indicators within it because of the importance of the energy sector and due to the good statistical database in this sector