Modeling Flexibility in Energy Systems - A Scenario-Based Comparison of Power Sector Model

Abstract

Model-based scenario analyses of future energy systems often come to deviating results and conclusions when different models are used. This may be caused by heterogeneous input data and by inherent differences in model formulations. The representation of technologies for the conversion, storage, use, and transport of energy is usually stylized in comprehensive system models in order to limit the size of the mathematical problem, and may substantially differ between models. This paper presents the results of a systematic, scenario-based comparison of nine power system models with sector coupling. We analyze the impact of differences in the representation of technologies, optimization approaches, and further model features on model outcomes. The comparison uses fully harmonized input data and highly simplified system configurations to isolate and quantify model-specific effects. We identify structural differences in terms of the optimization approach and technology modeling between the models. Furthermore, we find significant differences in technology modeling primarily for power plant ramping, battery electric vehicles, reservoir hydro power, and demand response. These depend largely on the specific focus of the models. We recommend the use of highly simplified use cases as best practice for future model comparison exercises, as they allow to isolate the effects of model-specific differences on results.