At the end of November 2025, the German Federal Ministry for Economic Affairs and Climate Action (BMWK) decided to amend the Power Plant Grid Connection Ordinance (KraftNAV). As a result, large battery storage systems with a capacity of more than 100 MW will no longer be able to connect to the grid under this procedure in the future. The decision currently does not provide for an alternative approval process, leaving it unclear how the grid connection of such large storage facilities will be regulated in the future.
Marc Untheim, Senior Business Development Manager at The Mobility House Energy, discusses the hurdles in the grid connection process in more detail and makes specific proposals for improvement.
For countless project developers, the question currently arises as to how they can implement their storage projects. According to media reports such as pv magazine Germany, this affects commitments for 51 gigawatts of grid connection capacity.
In a phase of uncertainty
The German Renewable Energy Federation (BEE) criticizes the fact that no new procedure was adopted before the removal from the KraftNAV. As a result, security and planning reliability for projects are no longer possible. “They are taking the second step before the first,” said BEE President Heinen-Esser in a statement from the association. Without a clear framework, there is a risk of long delays and even project cancellations. The 51 GW promised for large-scale storage have thus entered a phase of uncertainty.
Reasons for the decision
In principle, the number of grid connection requests is very high, both for large-scale storage systems and for smaller installations. The current regulation under the KraftNAV, based on the “first come, first served” principle, no longer seems to do justice to the volume and significance of these requests, according to the financial portal onvista.de.
Marc Untheim takes a critical view of the current procedure for connecting storage systems to the grid. “The so-called ‘first come, first served’ principle has led to speculation for years and has caused significant processing backlogs at many grid operators. In some cases, hundreds of requests have to be reviewed for a single grid connection point. From our perspective, a maturity-based model would make more sense, in which projects are assessed according to how far they have already been developed and how likely they are to actually be implemented. This would significantly improve prioritization.”
Relatively new challenges include flexible grid connection agreements. These often contain restrictions, such as limited power gradients – that is, specifications on how much power may increase or decrease within a certain period of time, both for feed-in and for offtake. “Such requirements make it considerably more difficult to calculate the profitability of flexible storage systems, especially since there are still no standardized criteria for this to date.”
In addition to the current legislative change, practical experience already shows that only a very small share of connection requests actually lead to realized projects: “The conversion rate is in the low single-digit percentage range. This is mainly because, for a single grid connection point, well over a hundred project developers often submit requests, of which in the end, only one project can be awarded the connection. This competition continues when developers approach multiple marketers, meaning that only a few of the many inquiries ultimately become finalized projects.”
In addition, there is considerable lack of transparency in the process. According to Untheim, developers often report long periods of positive verbal signals that are not confirmed in writing. In some cases, shortly before the expected approval, a standardized rejection without justification is issued. Such cases are extremely frustrating for project developers, as they may invest months or even a year in preliminary planning, permitting processes, and financing preparations – only for the project to be discontinued without comprehensible reasons.
“At least cooperation with the transmission system operators works when it comes to prequalification for ancillary services. For each individual storage system, we have to go through this process together with the transmission system operators. Across the four TSOs, the process is largely standardized and has been running reliably for quite some time,” says Untheim.
If the expansion of large-scale storage is delayed or blocked, the market ramp-up in the coming years could be slowed. This would affect the supply side, system flexibility, and market mechanisms. Overall, a more suitable procedure is needed that evaluates project applications both qualitatively and quantitatively. The maturity-based model could be the solution here.