(Frankfurt a. M., 11.02.2025) Thanks to the controllability of consumer units, end customers can be sure in the future that their new wallbox or heat pump can be connected promptly. However, when it comes to grid-oriented control, there are often three concerns: Is the connection to the system secure? Will consumers be too restricted by the grid-oriented control or suffer economic disadvantages? Network Technology and Operation Forum within VDE (VDE FNN), in coordination with the Federal Network Agency and the Federal Office for Information Security, has developed the basics in 2024 to refute these concerns and create clear guidelines for grid operators. At the beginning of 2025, VDE FNN published recommendations that, among other things, provide a practical classification of the guaranteed minimum power for end customers and specify how the grid status is determined. Heike Kerber, Managing Director of VDE FNN, explains: “Where grid congestion is foreseeable, the grid operator must intervene to control it. Every grid customer has a right to a minimum power supply from their controllable consumer units. We now have a standardized and practical nationwide basis for this.”
Supply guaranteed: minimum power supply for heat pumps, wall boxes and other devices
The grid-oriented control only affects controllable consumer units, such as heat pumps, wall boxes, air conditioning systems and storage units. The power consumption of daily needs in private households remains unaffected. The grid-oriented control is intended to avoid foreseeable local grid bottlenecks. To this end, grid operators can reduce the power of heat pumps, wall boxes, air conditioners and storage units to up to 4.2 kW in the event of bottlenecks and for a limited time. Charging, heating or cooling will always remain possible to a minimum extent. In addition, controllability offers end customers the opportunity to market their flexibility and reduce their electricity costs. In its recommendations, VDE FNN has defined how grid congestion is identified and how the minimum power of one or more consumer units at a location can be calculated reliably and uniformly throughout Germany.
Focus on measurement: the basis for grid-oriented control
Grid-oriented control is only applied where congestion occurs. To do this, the grid state is determined in real time. How much measurement data is required for this is described by VDE FNN in one of its recommendations. The basis for this was a study by the University of Wuppertal and consentec.
Kerber comments: “With this recommendation, we are creating a transparent and objective basis for grid-oriented control. The aim is to avoid both critical grid situations and unnecessary control interventions. Critical local grid situations can be averted by temporarily reducing individual plants locally and in time.” Grid-oriented control is not intended as a permanent solution: if demand occurs frequently or regularly, the operator is obliged to expand the grid in the near future.
Thinking ahead: IT security, dynamic tariffs and generation facilities
Grid-oriented control is only possible with a secure communication infrastructure: the IT security requirements for intelligent measuring systems with smart meter gateways are on a par with those of the secret service. This is expensive, but has proven to be a forward-looking decision for the critical infrastructure of energy supply. The current threat of hacker attacks means that the system developed in Germany can become a reference for countries that have not yet thought about market and grid integration in an integrated way and have not implemented it with the necessary cyber security.
With a view to better integration of low-voltage generation plants, further applications are being considered. For the inclusion of generation facilities – for example, PV systems – in the concept of grid-oriented control, VDE FNN recommends using the already developed principles for consumer facilities in the same way. This also provides a secure and standardized solution for customers to optimize consumption and generation and thus maximize the benefits of the dynamic tariffs introduced this year.
These and other topics will be discussed at the VDE FNN ZMP congress in Leipzig on June 25 and 26 (www.z-m-p.de).
