Zur Methodik von Effizienzbewertungen im energiewirtschaftlichen Kontext

In discussions concerning sustainability, climate change and the efficient use of resources, the terms energy efficiency, rational use of energy and resource efficiency are widely used. Each of those three terms corresponds to an assessment method. However, the terms and assessment methods are often used differently without an explicit definition of the actual approach. Therefore the major contribution of this article is the development of a framework of methodological characteristics to classify the three assessment methods.The three methodological characteristics of assessment methods are the definition of the object of investigation, the type of statement and the assessment setting. The assessment setting is specified by three criteria: balance boundary, aggregation level and measuring units.All three assessment methods rely on the concept of efficiency, defined as a utility-effort-ratio. The object of investigation influences the utility, which is formalized by a measuring unit. The balance boundary for the utility determines to what extent the utility is considered. The balance boundary for the effort describes which resources are captured for which upstream and downstream processes. The aggregation level describes the extent to which different resources are aggregated as one measuring unit. Monetary, physical or self-designed units are commonly used as measuring units.The plurality of possible manifestations of the balance boundary, the aggregation level and the measuring unit does not allow for a universally valid, precise definition of the three investigated assessment methods. Therefore the recommendations are: Firstly, when using an assessment method, the criteria of the framework should be used to document the approach. Secondly, the identification of the adequate assessment method should be based on a thorough discussion of goals and hierarchy of goals in politics.