Overhead line monitoring

For a flexible grid

A transmission system that adjusts to the weather

The feed-in of renewable energy is increasing dramatically during the energy transition. In order to transport the high load flows, all capacities of the power line system are needed. However, the transmission capacity fluctuates according to the season and the weather. At colder temperatures and due to the cooling effects of the wind, more electricity can be transported than at other times, such as hot summer days. This is due to the characteristics of the conductor cables: when the cables get hot, they expand and tend to sag more.

Thanks to overhead line monitoring, however, we have been able to significantly increase the load-bearing capacity of our electricity transmission system. This is possible by making exact calculations of the maximum possible load flows at the current weather conditions in order for the amount of slack on the cables to stay within the technical specifications. The parameters needed for these calculations, such as wind speed and ambient temperature, are measured directly at the electricity pylons. Based on the collected data, we then determine whether to transmit more or less electricity. If weather conditions are favourable, we are able to increase the load-bearing capacity of the power lines by up to 50 percent.

High Practical Relevance

The wind electricity from the north must be transported reliably throughout the entire country to reach the consumption-heavy south. This often pushes the electricity supply system to its limits. The management of weather-dependent overhead lines is thus an important step towards the successful integration of renewable energy. It allows for the more efficient utilisation of the existing system and prevents bottlenecks. At the same time, the expansion of the transmission system will be limited. 

Around 340 weather stations have been installed in our transmission zone.

By the end of 2022 at the latest, we will install a comprehensive network of measuring stations throughout our transmission zone. This will enable us to take action when wind speeds or temperatures change, and control our transmission system dynamically and efficiently.

Overhead line monitoring is a measure geared towards the optimisation of the transmission system and thus a component of the NOVA principle, which we take as our guideline for transmission system development.


How does TransnetBW use innovations to contribute to the energy supply of tomorrow? How do we meet demand for a more flexible, high-performing grid for the energy transition? By carrying out pilot and model projects as well as developing new technologies and processes in order to work towards a reliable energy supply in the future. 

Read more about our innovative projects under “Innovation – fit for the future”.