The basis for this long-term planning is the so-called scenario framework, which is approved by the German Federal Network Agency every two years. It sets out assumptions on future developments in generation, consumption, storage technologies, and existing grid expansion plans — looking up to 20 years ahead.
These assumptions feed directly into the preparation of the grid development plan, indirectly influencing strategic target grid planning and investment decisions of distribution grid operators.
The grid development plan is legally required. In this context, transmission system operators must comply with the provisions of the German Energy Industry Act (EnWG) and the German Grid Expansion Acceleration Act (NABEG) in particular.
Who prepares the Grid Development Plan?
The preparation of the grid development plan is led by the transmission system operators. Responsibility for Germany’s transmission grid is divided into four regions, known as control areas. The TSOs are responsible for maintaining system security, ensuring demand-oriented development, and operating the transmission grids in their respective control areas.
The four TSOs in Germany are:
- 50Hertz Transmission GmbH — responsible for north-eastern Germany
- Amprion GmbH — operates the grid in western Germany
- TenneT TSO GmbH — responsible for large parts of northern and southern Germany
- TransnetBW GmbH — responsible for the state of Baden-Württemberg
Grid connection of offshore wind farms in the North Sea is handled by TenneT, due to the location of suitable grid connection points, while connection of offshore wind farms in the Baltic Sea is handled by 50Hertz.
What are the outcomes?
The grid development plan identifies the measures needed for the transmission grid over the coming years to ensure a secure energy transition. This includes constructing new lines, expanding transmission infrastructure, reinforcing substations, and taking measures to integrate renewables. Together, the grid development plan and the environmental report form the draft of the Federal Requirements Plan.
What makes the grid development plan relevant for distribution grid operators?
For DSOs, the grid development plan provides an important guiding framework. While it primarily concerns the extra-high voltage grid, the developments it describes — such as new feeding points, changing load flows, or new grid nodes — often have direct implications for downstream medium voltage and low voltage grids.
The grid expansion plan is also playing an increasingly important role as a data source and planning basis for municipal heat planning and infrastructure projects.