Harmonizing Energy System Scenario Data Through Ontological Annotation: A Case Study Within the NFDI4Energy Ecosystem

Abstract

Long‑term energy scenario studies based on Energy System Optimization Models (ESOMs) play a central role in shaping the transition of the German energy system. However, the diversity of model structures and variable naming conventions complicate cross‑study comparison and limits reproducibility. This work presents an approach for improving the interoperability of scenario data through the use of ontologically annotated datasets.
Within the NFDI4Energy framework, we conducted a case study that tested a set of semantic tools and workflows on data from the Ariadne project, which employs the models REMod, REMIND, and PyPSA‑DE [1]. Using the Open Energy Ontology (OEO), the TIB Terminology Service, and the NFDI4Energy Annotator, we developed and evaluated a practical procedure for annotating energy scenario data in the IAMC format [2], [3]. The results demonstrate that automated suggestion tools substantially reduce manual effort while maintaining semantic quality after expert review. The documented workflow and derived recommendations aim to support scientists in performing transparent, reproducible, and machine‑readable energy scenario analysis