The number of requests for a connection to the transmission grid has risen rapidly in recent years, driven primarily by battery storage systems. The four transmission system operators (TSOs) alone have Connection requests for around 211 GW before. By way of comparison, the conventional coal and gas power plants in operation all have a combined output of around 65 GW. The previous “first come, first served” principle in the KraftNAV (Power Plant Network Connection Ordinance) created an endless traffic jam of connection requests. The result: Requests with a low probability of implementation block other more promising projects due to the earlier date of application submission.
With the adjustment of KraftNAV on December 24, 2025, it was clarified that this procedure no longer applies to battery storage systems:
The TSOs have now agreed on a maturity process — and thus initiated a paradigm shift.
The new maturity process follows the principle of “first ready, first served” and replaces prioritization by request date with prioritization based on project maturity. The aim of the UDBs is to allocate the technically limited grid connection capacities to the projects with the highest probability of implementation. The process is divided into three phases:
At the start of the process, the TSOs publish the available grid connection capacities — both in terms of transmission capacity and technical connection options. This step also gives you the opportunity to clarify open questions. In addition, the UDBs offer interested parties (petitioners) to check their application documents for completeness. The information and application phase ends after three months with a binding deadline by which follow-up inquiries can be submitted. In addition to compliance with the deadline, a follow-up fee of 50,000 euros must be paid for further processing of the request.
After the deadline, the TSOs will review all applications submitted on time and assess project maturity based on four categories:
1. Area protection & permit status
2. Technical concept
3. Performance of the petitioner
4. Network & system benefits
Each category includes minimum requirements, such as an approval concept or a robust project plan. In addition, additional points will be awarded for other milestones that have already been achieved.
Example: A concluded lease or purchase agreement results in a higher score than a notarized reservation agreement.
All four categories are equally weighted into the overall rating of 25 percent. If the minimum requirements are met, each application is added to the priority list based on its score. On this basis, the TSOs then decide — starting with the top-rated project — how the projects can be allocated in terms of vacant control panels, performance capacities at the site, stability criteria and the availability of project resources. If no connection is possible, the application will no longer be considered.
As the last step of the cluster study, interactions between the individual projects are checked and whether the transmission network can handle the sum of all projects. If this is not the case, the performance of projects with lower maturity is reduced first.
In the last phase, all petitioners receive detailed feedback. Network connection cancellations include the number of points achieved and the minimum number of points that would have been required for a connection commitment. Commitments include information on the grid connection capacity, the grid connection point and an indicative connection date. If the connection offer is accepted, a reservation fee of 1,500 euros per MW must be paid. The acceptance period is one month. Unaccepted offers are passed on to successors, who also have one month to decide.
The data situation shows the urgency of the reforms: More than 50 GW of connected power is already reserved for battery storage at ÜNBs. These 50 GW connection options are blocked for an indefinite period of time, without proof or verification of project readiness. These reservations that have already been made remain unchanged; there is no subsequent verification of the maturity level. The maturity process is therefore only used for new or incomplete follow-up requests.
(Personnel) resources are limited not only for network operators but also for specialist companies for pipeline construction and project planning. Through the maturity process, these limited resources should be directed to projects that make the biggest contribution to the success of the energy transition. The maturity process sets uniform standards, creates fair and comprehensible priorities, relieves transmission system operators and provides serious project developers with reliable framework conditions.
For us as project developers and operators of large storage systems, this means that we have to do more preparatory work before we can get clarity as to whether a network connection is possible for the planned project. Expenses are therefore shifting from the network operator to us as project developers. However, in accordance with the currently defined maturity criteria, the necessary advance payment remains within feasible scope — the audit costs of the network operator for the connection request and the effort required for preliminary planning during project planning appear to be in reasonable proportion. We are therefore looking forward to the start of the maturity process on April 1, 2026 with the publication of the follow-up potentials.
Internationally, Germany is catching up with the new maturity approach: Since 2025, the EU Commission has been calling for the introduction of maturity criteria in grid connection processes and several neighboring countries have already taken concrete reform steps. Since 2025, Great Britain has relied on a “first ready, first served” process with tough maturity criteria and annual proof of progress. Norway has introduced a legally enshrined examination for projects over 1 MW, which makes land security and proof of financing mandatory. France combines minimum criteria with annual project progress, lump sums and penalties for inactivity.
Further reforms are needed to resolve the backlog of network connection requests at all network levels and to allocate network connections efficiently:
The maturity process already rates projects with network and system benefits higher in terms of priority, but so far exclusively on the basis of project hybridization. This encourages efficient use of switch panels, but another added value remains unused: The system-stabilizing functions of modern battery storage systems. In particular, their ability to provide frequency maintenance, reactive power supply, black start capability, congestion management or other system services could make a significant contribution to the transformation of the electricity system. Storage that reliably provides such services should therefore receive a measurable maturity bonus.
The maturity process is used for all connection requests with the exception of renewable and conventional power plants. Storage, data centers, hydrogen production and industrial plants therefore compete for network connections in a connection process. Now that grid connections have been allocated for the first time in 2026, it must be assessed whether this competition will result in an unilateral allocation of network connections and may have to be counteracted with upper limits for system classes in the future.
So far, the new procedure is intended to apply exclusively to grid connections of transmission system operators. However, the traffic jam of grid connection requests at ÜNBs has only arisen because the distribution system operators (DSOs) were previously flooded with network connection requests for medium and high voltage. In addition to 211 GW connection requests from the UDBs, there are a further approximately 600 GW of inquiries from the VNBs. So far, the new procedure is intended to apply exclusively to grid connections of transmission system operators. If the maturity process proves successful, it is obvious to roll it out to other network levels.
With our experience of more than 2.5 GW of projects developed ready for construction and the transition to an Independent Flexibility Provider (IFP), Kyon Energy is actively involved in the development of a modern grid connection process. We are in close contact with politicians, the Federal Network Agency, transmission system operators and relevant associations to ensure that flexibility as a key resource in the energy transition receives the regulatory framework it needs.
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