Electricity grid reserve capacity requirements confirmed
Klaus Müller, Bundesnetzagentur President: "Secure system operation requires grid reserve power plants"
Year of issue 2026
Date of issue 2026.05.22
The Bundesnetzagentur has confirmed a total grid reserve capacity requirement of 7,407 megawatts (MW) for winter 2026/2027. For winter 2025/2026 it was 6,493 MW.
"Until we have further expanded the networks, a grid reserve is necessary to ensure the security of electricity supply. The requirement for the coming winter is slightly higher than for last winter,
" said Klaus Müller, President of the Bundesnetzagentur.
Capacity requirements for a winter further in the future are routinely identified as well. For winter 2028/2029, the required grid reserve capacity has been put at 8,274 MW.
Grid expansion remains the most important tool for reducing reserve capacity requirements
The transport tasks in the electricity grid are growing. The reasons for this include, for example, the ongoing expansion of renewable energies and the need to increase cross-border trading capacity. Only with further grid expansion will it be possible to fully utilise renewable energies and to facilitate exports and imports of electricity that are essential for ensuring a secure electricity supply. Until then, there will continue to be high demand for redispatch from operational plants and the supplementary contracting of reserve power plants.
Provision of grid reserve capacity
A large part of the grid reserve capacity of 4,742 MW needed for winter 2026/2027 will be covered by German reserve power plants. As in previous years, the remaining capacity requirement of 2,665 MW will be provided by power plants in neighbouring countries. Transmission system operators already issued a call at the beginning of May 2026 for foreign power plant operators to express their interest by 19 May 2026 in providing grid reserve capacity. Transmission system operators’ contracts with foreign power plant operators are concluded in agreement with the Bundesnetzagentur.
Reserves for system stability
Congestion occurs when the transmission network is overloaded. Contracting reserve capacity serves to prevent this from happening. This is done by reducing generation in front of an impending congestion in the grid and at the same time increasing generation behind the congestion.
This mechanism, known as redispatching, is carried out by first using power plants that are operational in the market. In certain situations, however, the active plant capacity is not sufficient to relieve the congestion. In such cases, additional grid reserve power plants are activated. The German grid reserve consists of power plants that no longer operate on the market for electricity generation but cannot be shut down permanently as they have been categorised as important for the system. These power plants may only be used when instructed by the transmission system operators. Foreign grid reserves consist of power stations that have entered into contracts with the German transmission system operators to feed electricity into the grid for redispatch purposes. The costs for contracting and using the power plants are refinanced through the network tariffs.
The transmission system operators had already presented their system analysis and the resulting grid reserve capacity requirements to the Bundesnetzagentur for evaluation. The determination of the grid reserve capacity is the final step in the Bundesnetzagentur’s evaluation process.
The report (in German) has been published at www.bundesnetzagentur.de/netzreserve.
