Large Battery Storage Cooperation Forum: Challenges and Solutions
Discussion Paper
This discussion paper is the result of the Large-Scale Battery Storage Cooperation Forum and is aimed at policymakers and regulatory authorities as well as grid operators and representatives of the storage industry. The forum was launched by FfE in August 2025, when reports of a storage boom and grid connection shortages were spreading rapidly. In a situation marked by considerable uncertainty and sometimes heated debate, a space was created to enable a neutral assessment of the challenges, to take the discussions to a deeper level and to work together in a structured manner to find solutions. The key topics for the cooperation forum were defined in consultation with the stakeholders involved. Over 50 companies from the grid and storage industry participated in the forum and contributed to four areas of action. The discussion was constructive, as the companies share the fundamental view that large battery storage systems are a valuable component of the future energy system and that grid integration can be achieved with the right tools.
Not all of the solutions discussed are supported by a broad consensus. However, working together in the forum has made members aware of each other’s challenges and made it possible to discuss all aspects of potential solutions from an implementation perspective. As a neutral coordinating body, FfE contributed background research and scientific analyses to promote understanding of the interdependencies and systemic effects. Parallel to the work within the forum, there was a constant exchange with ministries, associations and the regulatory authority. The following pages briefly outline the most pressing challenges and possible solutions for each field of action. A detailed overview of the consensus on the solution components can be found in the main part of the paper.
Regulatory Changes and Strong Interactions
Parallel to the forum’s work, the regulatory framework in the key areas of activity underwent profound changes. As of February 2026, a grid connection package from the German Federal Ministry of Economic Affairs and Energy is imminent. Although experience is being gained with FCAs, there is still no clear political target for them. At the same time, the Federal Network Agency’s “AgNes” and “MiSpeL” determination procedures are underway, but the specific target is still unclear to many outsiders. The work in the forum has made it clear that the acceptance of the participating companies depends significantly on the detailed design of the solution components. At the same time, there are sometimes strong interactions between the fields of action, which is why it is nearly impossible to make detailed specifications in one area as long as the framework conditions in other areas cannot be estimated. It is therefore all the more important that politicians and regulatory authorities closely coordinate on the decisive issues and take practical perspectives into account in their proposals.
Grid Connection Requests
The grid connection situation in Germany is currently very tense, particularly due to the large number of grid connection requests from large-scale battery storage facilities, some of which are submitted at a very early stage of project development. Storage facilities have now been removed from the scope of the KraftNAV, but without specific successor regulations being created. In the distribution grid, where plants have not been covered by KraftNAV to date, there is also dissatisfaction with incomplete applications, inappropriate, often paper-based processes and delayed responses. We therefore propose five building blocks for a sustainable grid connection procedure, many of which are reflected in the recently published concept of the transmission system operators and in the draft bill of the Federal Ministry for Economic Affairs and Energy on improving the grid connection procedure. Uniform maturity criteria and financial proof of seriousness should help to significantly consolidate the existing application backlog. To be able to prioritise plants according to political guidelines, it will also be necessary to evaluate applications collectively in a regular procedure in future. For political prioritisation, we outline various design options and make suggestions for a transparent map display of available connection capacities. The application of the tools – and thus the implementation effort – is ultimately the responsibility of the grid operators. However, in order to create legal certainty for all parties involved, the regulatory requirements for the grid connection procedure must be robust and unambiguous.
Flexible Connection Agreements
Flexible Connection Agreements (FCAs) are currently being used to address a wide range of challenges in the grid integration of batteries: from accelerating the grid connection and ensuring grid stability to reducing grid expansion costs in the long term. The lack of a uniform target vision is currently leading to a very heterogeneous design of FCAs, which can result in discrimination between projects and locations. The situation also poses a risk in terms of excessive (inefficient) intervention in storage operation – especially given today’s intensified competition for free capacity. FCAs are an important instrument for the grid integration of batteries. We therefore recommend greater standardisation of the restrictions that can be agreed in FCAs and propose possible key points for appropriate compensation for the restrictions. Both would also form the basis for using FCAs as a fully-fledged instrument in congestion management. In addition, clarification by the regulatory authority on the use of FCAs to reduce the need for grid expansion in the interests of targeted design would be desirable.
Grid Tariffs for Storage
The work in this field of action was based on the discussion paper published by the Federal Network Agency in May 2025 on the framework for the general grid tariff system for electricity (AgNes). The guidelines on storage grid tariffs published in January 2026 could no longer be taken into account. In this field of action, the impact of the individual proposals from the Federal Network Agency’s discussion paper on storage was discussed and proposals for their precise design were developed. When introducing feed-in tariffs on connection-related components, double charging can only be avoided if a special regulation is created for storage facilities or if areas are defined in which storage facilities pay one or the other. It was noted that the capacity price has neither advantages nor disadvantages for storage facilities compared to the current power price. However, there is a risk of economic overload in the static design, especially if there are restrictions due to FCAs. Discounts on grid fees when concluding an FCA could reduce the financial impact. However, this would require a certain degree of standardisation in the design of FCAs. For a dynamic working price, a symmetrical, sign-appropriate tariff is recommended to avoid distortion.
Co-Location
Co-location is increasingly being considered as a solution for the efficient use of scarce grid connections and for the integration and refinancing of renewable electricity plants. However, various plant configurations, storage operating modes and operator relationships pose challenges in practical implementation and for appropriate regulation, particularly in the often-desired multi-use case. Five approaches for leveraging co-location potential were developed in this field of action. In the grid connection process, this involves increasing transparency regarding potential locations and making adjustments to ensure adequate representation in application forms, as well as providing guidance on various plant configurations. We also present various target scenarios according to which co-location projects can be prioritised in the grid connection sequence. For co-location storage facilities, the “MiSpeL” procedure is an important driver for maintaining netting options or EEG subsidy conditions in multi-use cases. We consider an extension or consistent application of MiSpeL to be beneficial (e.g. also regarding grid fee regulations for storage facilities). The spatial positioning of the storage facility at the grid connection point offers potential for shifting the feed-in of renewable energy depending on the grid situation but requires appropriate signals. We see FCAs as a key element of targeted co-location, also with regard to their ability to define interaction and prioritisation rules between the plants. For redispatch, it is recommended that the grid connection be defined as the reference point. The approaches address legislators, the Federal Network Agency and grid operators and aim to establish a clear and transparent basis in terms of regulation and procedure.
The following companies participated in the cooperation forum and contributed to the development of solutions:
