Peh, Anna-LenaAnna-LenaPehKrämer, KaiKaiKrämerSchmeyer, ThomasThomasSchmeyerRohrbach, DanielDanielRohrbach2025-06-242025-06-242025https://publica.fraunhofer.de/handle/publica/48889310.1109/ICSC64641.2025.00023In the European energy sector, the integration of disparate data sources can be a crucial factor in enhancing operational efficiency and stimulating innovation. This paper presents a case study on the implementation of domain-specific ontologies in an Energy Data Space (EDS), with the objective of achieving semantic interoperability in this data ecosystem. The study demonstrates how the implementation of the International Data Space Reference Architecture Model Version 4 (IDS-RAM 4) and the utilization of diverse energy-specific vocabularies can facilitate consistent data representation, the integration of use cases within a domain, compatibility with established formats, such as the Common Information Model (CIM), and interop-erability between different systems. The proposed approach is validated using two key use cases: the provision of data from a digital twin and energy measurement data. The results highlight the potential of semantic technologies to create a more resilient, secure, and efficient data ecosystem for the energy sector. Index Terms-decentralized data management, data space, energy market communication, energy sector, ontology, eclipse dataspace components, IDS-RAM 4, IDSA, CIM, Common Information Model, ECLASS, Open Energy Ontology, Asset Administration Shell, linked data, CIM compatibility, semantic interoperability, eclipse data space connector, IoT, IDTA, JSON-LD, data ecosystemendecentralized data managementdata spaceenergy market communicationenergy sector,ontologyeclipse dataspace componentsIDS-RAM 4IDSACIMCommon Information ModelECLASSOpen Energy OntologyAsset Administration Shelllinked dataCIM compatibilitysemantic interoperabilityeclipse data space connectorIoTIDTAJSONLDdata ecosystemconference paper