380-kV Berlin Diagonal Power Link: Reuter – Teufelsbruch

The energy transition is changing power flows and leads to more stringent requirements for the transmission grids that transport the electricity from generation to consumption centres. This also applies to the capital, especially considering the energy demand that is predicted to keep rising until 2045. By expanding and upgrading the transmission grid in Berlin’s metropolitan area, 50Hertz is fulfilling its social mandate to also secure the energy supply in the future.

Hence the official mandate: Project no. 87, designated in the Federal Requirements Plan Act (Bundesbedarfsplangesetz, BBPlG), consists of several individual measures in the larger Berlin-Brandenburg area, all with the goal to improve the region’s security of supply in times of a changing energy landscape and increasing power demand. The cable tunnel project between Reuter and Teufelsbruch in Berlin’s Spandau district is part of this official package of measures.

Project overview

Line route

The project between Reuter and Teufelsbruch has a route length of approximately six kilometres and is primarily planned as a cable tunnel. The objective is to plan and build a cable tunnel with an inner diameter of approximately four metres at a depth of up to 40 m. This requires three shaft sites as aboveground construction sites; the rest of the civil engineering work is carried out below ground:

• A start shaft, where construction work will begin and the tunnelling machine is set up below ground. A location for this shaft (as well as the corresponding building site equipment areas) is being sought for near the Reuter cogeneration plant. Surrounding the substation located there, new buildings and expansions are also being established to upgrade the installations for the future transmission grid.
• An intermediate shaft to guarantee occupational safety and the supply of materials for the deployed staff. Its location needs to be found around the halfway point of the Wasserstadtbrücke/Daumstraße area.
• At the end shaft, the cable tunnel then reaches its destination at the existing Teufelsbruch substation.

The new cable tunnel will replace the existing line, which is an underground cable running underneath Spandau at a depth of approximately two metres. Built at short notice in 1994 in the context of the German reunification, the current-carrying capacity of this cable no longer suffices to ensure the future electricity supply. The existing line must remain on the grid until the new cable tunnel is commissioned so as not to put the ongoing operation of Berlin’s transmission grid at risk.

Next steps

50Hertz is now starting work on the application documents for the planning approval procedure under §43 of the Energy Industry Act (Energiewirtschaftsgesetz, EnWG). These should be submitted to the competent permitting authority, the Brandenburg State Office for Mining, Geology and Raw Materials (Landesamt für Bergbau, Geologie und Rohstoffe, LBGR), in 2028.

Public participation

In May and July of 2025, 50Hertz outlined the project on site during a total of five information events, both for the authorities involved as well as interested citizens and residents living near the potential shaft sites.