As of early 2026, German grid operators have received grid connection requests for around 720 GW of battery storage (nine times the annual peak load), but they struggle to accommodate this influx, leaving asset owners faced with multi-year delays. So-called FCAs (flexible connection agreements) were introduced to make grid connections possible even in congested areas and to offer BESS owners faster grid connections in exchange for accepting limitations on marketable flexibility. By restricting grid use, TSOs (Transmission System Operators) and DSOs (Distribution System Operators) aim to alleviate grid congestion and drive the integration of renewables and storage. As FCAs become the norm for grid connection procedures, project developers are concerned about the financial viability of battery storage.
It’s important to note the current ambiguity of grid constraints. There are three things we know for certain. One: Grid limitations are underway. Two: They will impact BESS business cases. Three, FCAs aren’t standardized. Limitations can target several categories, including commercial (participation in ancillary services), temporal (permitted time windows for (dis)charging), and technical (ramps), with multiple variations possible within each.
To understand the commercial pressure associated with FCAs, we need to examine the practical interpretation of these arrangements. The degree of restriction always depends on the respective grid operator and each individual FCA contract. BESS revenues are far less affected if only partial restrictions apply, and certain constraints are more financially feasible than others. That’s why network-specific information and general prudence are paramount during FCA negotiations. In the end, it’s in the interest of both negotiators, the grid operator and the project developer, that batteries are profitable and continue to be built.
Limits on power flows, slower ramp rates, and controlled participation in ancillary services affect battery business cases and challenge associated revenue expectations. How can we mitigate this risk and profitably position battery systems in the markets despite these complex regulatory conditions? Given the multilayered execution of constraints, revenue predictions can’t be generalized. The ultimate outcome depends heavily on the extent of your limitations, but enspired’s live optimization of restricted assets across Germany shows that value can still be maximized.
Controlled interference in ancillary service participation entails the most significant revenue cuts, while curtailments, charging restrictions, and discharging obligations are easier to manage and often depend on surrounding wind and PV installations. Active experience with restricted assets in cross-market optimization indicates that revenue maximization under FCAs is feasible and profitable when key parameters are considered.
FCAs raise valid concerns, but they can be implemented in a way that supports commercial BESS optimization. Maintaining a close dialogue, including constructive proposals and counterproposals, between the asset owner and grid operator ensures transparency throughout the contracting process. Early involvement of a bankable optimizer helps you secure the most beneficial FCA structure and leverages real-world experience optimizing restricted assets in Germany. Proof of performance provides assurance that the commercial optimum is achievable even for assets with adverse starting conditions. In a market landscape shaped by regulatory complexities, proactive communication and operational expertise in navigating constraints are key to preserving the viability of your BESS project.