PLANET: optimum utilisation of the technical rules for efficient grid planning

The planning of electricity grids is becoming more complex due to the growth in electrification. The project identifies challenges in the application of planning rules and makes recommendations for the inclusion of intelligent solutions.


  • Lead school School of Engineering and Computer Science
  • Institute Institute for Energy and Mobility Research IEM
  • Research unit IEM / Power grids
  • Funding organisation Schweizerische Eidgenossenschaft (Bundesverwaltung)
  • Duration (planned) 01.11.2023 - 30.03.2027
  • Project management Prof. Michael Höckel
  • Head of project Prof. Michael Höckel
  • Partner Bundesamt für Energie BFE
  • Keywords Electrification, electricity grid, technical rules, connection requests


Increasing electrification due to electric mobility, the replacement of fossil-fuel heating systems with heat pumps and the expansion of photovoltaic systems add up to a greater load on the Swiss electricity grid. This calls for a certain degree of reinforcement and expansion of the distribution grids in order to avoid overloads and ensure a high voltage quality. Distribution system operators use the DACHCZ “Technical Rules for the Assessment of Network Disturbances” (TRBNr) for grid planning in order to coordinate the voltage quality and evaluate connection requests. However, these rules do not take into account the possibilities presented by intelligent systems in distribution grids. This raises the question of whether the current planning principles are sufficient for cost-efficient grid expansion, or whether they might need supplementing, particularly with regard to the deployment of smart grid technologies.

Course of action

It is essential to know the degree of utilisation and simultaneity factors in order to correctly plan the distribution grid. The project is therefore comparing the current practice for assessing connection requests received by the grid operators and analysing the voltage quality in selected grids, in order to obtain more specific findings and make recommendations for supplementation of the current TRBNr DACHCZ. Field measurements are used to measure the actual impact of customer PV systems on the electricity grid in a real environment. Laboratory measurements can also be used to explore and simulate the impact under controlled conditions. The combination of field and laboratory measurements will facilitate a comprehensive understanding of the impact of new customer systems on the electricity grid. These findings can be used to supplement the current rules regarding the efficient connection of modern customer systems (photovoltaic systems, charging stations, heat pumps, etc.) to the electricity grid. Finally, an open-source software tool will be programmed to support network operators as they assess connection requests in accordance with the third and latest version of TRBNr DACHCZ.


The project goes beyond the current state of knowledge and offers recommendations for the inclusion of intelligent systems in the assessment prescribed by TRBNr DACHCZ. The project seeks to answer the question of what possibilities modern measurement and control systems offer for deviating from threshold values specified by the Technical Rules. The project also seeks to identify possible solutions to eliminate current obstacles in the assessment of connection requests and to continue developing an open source software tool that supports the assessment of connections. It will also draft guidelines and recommendations for training documents and document guidance for network planning. It will propose benchmarks for simultaneity factors and utilisation rates for different grid areas and system types. It will incorporate significant insights gained from practice, including recommendations on when a new grid connection should be checked using measurements. The aim is to ensure a cost-efficient distribution grid despite the growing numbers of grid connections.

Looking ahead

It is extremely important for network operators to identify obstacles and opportunities for improvement when dealing with the TRBNr DACHCZ. Understanding these rules and observing the experiences of other grid operators can grant additional insight into the impact of modern devices and systems on the grid and lead to effective solutions for optimising and expanding the electricity grid. The TRBNr DACHCZ provide a methodological basis for determining grid disturbances and are an indispensable tool in the planning of electricity grids. The project will identify where the rules of TRBNr DACHCZ should be supplemented in order for grid planning to take appropriate account of intelligent monitoring and control systems that are currently available, in the interests of cost-efficient grid construction. By expanding their knowledge and experience in dealing with the TRBNr DACHCZ, grid operators will be in a position to better factor in the influence of modern devices and systems. This will enable them to perform a more informed assessment of the grid connections of photovoltaic systems, charging infrastructure and heat pumps with respect to cost-efficient grid planning.

This project contributes to the following SDGs

  • 7: Affordable and clean energy
  • 9: Industry, innovation and infrastructure