The gap between energy policy challenges and model capabilities

Ambitious decarbonization targets, technology-specific policies, and computational developments led to increases in the complexity and diversity of energy system models. The lack of transparency and standardization, however, renders the assessment of model suitability for specific policy questions difficult. Therefore, this paper systematically assesses the ability of energy system models to answer major energy policy questions. It examines the existing literature on model comparison schemes, then proposes a set of criteria to compare a sample of 40 models. Besides, a novel, model-oriented approach is developed in order to cluster energy policy questions. Finally, the model capabilities and the policy questions are brought together by quantifying the gap between models and policy questions. The results show that some models are very well able to answer a wide range of energy policy questions, whereas others are only suitable for a specific area of energy policy. The representation of the distribution grid, the endogenous adjustment of demand, and the technical flexibility of the energy system are among the features, where models generally lag behind. Our results provide policy-makers with guidance on crucial model features with respect to a selection of energy policy questions and suggest potential funding priorities for future energy system modeling.