Köhler, NeleNeleKöhlerStappel, MirjamMirjamStappelMuschner, ChristophChristophMuschnerEmele, LukasLukasEmeleHofmann, ChristianChristianHofmannFörster, HannahHannahFörster2025-05-062025-05-062024-07-15https://publica.fraunhofer.de/handle/publica/487338The Open Energy Ontology (OEO) is being developed as a domain ontology for energy system modelling.To increase its usability and react to user requirements, we introduce a post-coordination extension toOEO, the Open Energy Ontology Extended (OEOX). We create OEOX as an ontology for specific energy-related terms with a high complexity that go beyond the level of detail of the standard OEO class hierarchy.It allows for a dynamic ontology composition, enabling precise and tailored annotations for energysystem data sets, requiring only minimal manual intervention or curation. In this paper, we describethe user-driven motivation for this ontology extension (Section 2). We illustrate the methodology andearly-state practical implementation on behalf of post-composition patterns (Section 3). The ontologicalannotation of datasets in real-world applications and the usage of OEOX is described in Section 4,complemented by conclusions and summary in Section 5.enOntologyconference paper