The Open Energy Platform in NFDI4Energy: A collaborative Data Infrastructure for Energy, Climate, and Mobility Research

The Open Energy Platform (OEP) [1] is a modular, web-based infrastructure designed to support open, transparent, and reproducible energy system modelling. Developed as open-source software, it offers services from the Open Energy Family (OEFamily) that enable the standardized publication, documentation, and reuse of energy-related data, models, and scenarios [2]. This article presents the main services and outlines the technical and conceptual framework with the overarching aim of enhancing interoperability, improving data quality, and fostering collaborative research in the energy domain. The core component of the platform is the Open Energy Database (OEDB), a collaboratively used relational database for openly licensed datasets [3]. It stores a wide range of datasets, including input and output data from various energy system models. The database is organized into 11 thematic topics relevant to the energy domain, along with two additional topics for work-in-progress and scenario-specific data (model_draft and scenario). Built-in data versioning ensures reproducibility and traceability by maintaining structured records of dataset changes over time. The Open Energy Metadata standard (OEMetadata) ensures FAIR and high-quality metadata. Its associated editor, the OEMetaBuilder, supports the creation and editing of metadata records [4]. OEMetadata supports the comprehensive description of datasets with multiple resources (e.g. tables) and incorporates contextual information such as the research project, spatial and temporal coverage, data sources, licensing, and chronological provenance. The standard is based on the Frictionless Data Package specifications, DCAT-AP 3.0 and the FAIR Principles. It was designed with consideration of existing standards, including Dublin Core, INSPIRE, DataCite, schema.org, and PROV. A badge system prioritizes the keys and measures completeness and quality. The developed Open Peer-Review Process (OPR) enhances reliability through community validation, feedback, and iterative improvements, ensuring transparency and trust. The Open Energy Ontology (OEO) [5] is a domain ontology developed collaboratively to formally represent concepts and relationships relevant to energy system analysis. It is based on the Basic Formal Ontology (BFO), ensuring logical consistency and interoperability. It reuses and aligns with several established ontologies such as units of measurement, time, and geospatial references. Based on the OEO, the Open Energy Knowledge Graph (OEKG) enables standardized documentation of energy scenarios (Scenario Bundles) and models [6]. The Virtual Knowledge Graph (OEVKG) enables comparison of models and scenarios across datasets. The Open Energy Academy provides Open Educational Resources (OER) on RDM in climate and energy systems modelling. As part of the OEP, it offers Courses, Tutorials, and Questions (FAQ) to support users in utilizing the platform effectively. It is hosted on GitHub Pages and built using MkDocs. In NFDI4Energy, the OEP contributes established services and offers a basis for future applications by the energy research community [8]. Further developments and improvements of the platform are underway, such as the integration of NFDI base services, including identity access management and the terminology service. By consistently applying open licenses, the OEP fosters collaborative and sustainable research data practices in energy systems analysis and serves as a key data infrastructure for energy, climate, and mobility research.