The DSO Interface and Knowledge Engine - White Paper

The European energy transition demands unprecedented coordination between Distribution System Operators (DSOs), building energy management systems, and distributed energy resources. This white paper examines how the DSO Interface, developed within the EU Horizon 2020 InterConnect project and now being adapted by the BlueBird project, enables standardized semantic communication of market prices and flexibility signals across heterogeneous energy systems.

The DSO Interface addresses a fundamental challenge: how can a DSO in Belgium, another in Spain, another one in Germany and another in Poland all communicate with diverse building systems using a single, universally understood protocol? The answer lies in semantic interoperability, where systems share not just data formats but a common understanding of what that data means.

Key findings of this paper: The Knowledge Engine, developed by TNO as part of the Semantic Interoperability Framework (SIF), provides a distributed peer-to-peer architecture that enables intelligent data exchange without centralized databases. Unlike traditional REST APIs where clients must know specific server endpoints, the Knowledge Engine allows systems to describe what knowledge they can provide or need, with automatic discovery and matching of compatible services.

The InterConnect project validated this approach across 7 European pilots with over 50 integrators, demonstrating that semantic interoperability through SAREF (Smart Applications REFerence) ontologies enables plug-and-play integration of energy services. BlueBird now extends this foundation to building-integrated flexibility trading, deploying the Knowledge Engine to communicate market prices from energy exchanges to Building Energy Management Systems (BEMS) and Flexibility Managers.