Preparing Dutch DSO-DER interface for large-scale role-out using IEC 61850 and WebSocket

The energy transition is causing an increasing load on the electricity grid due to distributed energy resources (DER) such as solar energy systems and wind turbines, prompting Dutch grid operators to apply congestion management methods and strengthen the infrastructure, supported by regulatory changes. In 2020, Netbeheer Nederland (NBNL) started a project with market parties to develop the Realtime Interface (RTI), which enables grid operators to exercise real-time control over customers with production installations >1 MW to ensure safe system operation when other methods fail. The first version of the RTI specifications was released in February 2024 and is currently the Dutch reference standard. One of the disadvantages of the current RTI version is the need for hardware at the DER location, including a direct ethernet connection. This hinders large-scale rollout due to the required scarce technical workforce and limited implementation flexibility for customers. To support a large-scale RTI rollout, NBNL is working on a future version that addresses these limitations. This paper will give insight into the first steps of this journey.