Foundation stone laid for substation extension in Steglitz-Zehlendorf 

Next milestone for the Stromnetz Berlin construction project eight months after the ground-breaking ceremony

20.11.2025

Stromnetz Berlin wants to double the capacity of Berlin's electricity grid by the early 2030s. This will also strengthen the security of supplies in Steglitz-Zehlendorf. Part of the grid expansion programme in the district is the Claszeile substation, which is currently being expanded. The foundation stone was laid today, 19 November, just eight months after the ground-breaking ceremony. The current system, which is situated opposite the Süd-Grundschule and dates back to the 1970s, has reached the end of its service life. A modern plant that will supply several tens of thousands of households in the district is to be built on the same site by the end of 2031. Stromnetz Berlin is investing around 32 million euros in the project. 

The foundation stone was laid by Steglitz-Zehlendorf's District Councillor for Urban Development, Patrick Steinhoff, Christa Arnet, representative for the district on Stromnetz Berlin's Citizens' Council, Dr Stefan Rolauffs, Head of "Grid Development", and Thomas Rütting, Head of "Politics & Communication" (both Stromnetz Berlin). 

Thomas Rütting, Head of "Politics & Communication" at Stromnetz Berlin: "Implementing our construction projects for a secure and resilient power supply quickly - that is always our goal. Just eight months after the ground-breaking ceremony, we can now lay the foundation stone for the expansion of the Claszeile substation. This is a good signal for Zehlendorf and the whole of Berlin. New substations and grid nodes are currently being built in many parts of the city. Thousands of kilometres of new cables are being laid. In 2025 alone, we invested 467 million euros in the Berlin electricity grid." 

Patrick Steinhoff, district councillor for urban development in Steglitz-Zehlendorf: "The Steglitz-Zehlendorf district authority constantly strives to support the further development or creation of new locations for substations in the interests of security of supply for our citizens. We are happy to discuss this with Stromnetz Berlin." 

Preparations for the construction on Claszeile have been underway since the end of 2023. The transformers were replaced some time ago. A similar extension will be built on the site of the former Claszeile plant by the end of 2026. The topping-out ceremony is scheduled for summer 2026. The electrical components - including a modern and environmentally friendly switchgear system - will be modernised by the end of 2031. At the same time, new power cables will be laid in the vicinity and on the site of the substation between 2027 and 2030. The roof of the new substation is being prepared for the installation of a photovoltaic system. 

The power supply will not be interrupted while these works are carried out. Access to private properties and escape routes will be maintained at all times. 

Stromnetz Berlin is also temporarily using one of its own plots of land for the construction, which has so far been used as a playground and provided free of charge. Once the work has been completed, Stromnetz Berlin plans to build another playground there and will again make it available to the previous user free of charge. 

The company regularly updates citizens on the next steps in the construction project as part of the citizens' dialogue.