Major German BESS outcomes: Grid fee exemptions remain, higher costs for prosumers

Germany’s Federal Network Agency (Bundesnetzagentur) presented its preliminary interim report on the reform of the General Grid Fee System for Electricity (AgNes) on Wednesday. The findings will feed into a draft framework determination, which will undergo a “formal consultation” this summer before being finalized by the end of the year.

“With a new grid fee system, we want to boost cost efficiency and achieve a fair distribution of the burdens. Our goals: to allocate costs where they are incurred. To put a price on scarce capacities. To avoid congestion management costs,” said Klaus Müller, President of the Bundesnetzagentur. The overarching aim is to support flexibility and reduce both grid expansion and redispatch costs.

The crucial statement from Müller, which the battery storage industry had surely been hoping for, is: “We are placing greater emphasis on the protection of legitimate expectations than in our previous proposals.” This means that the existing exemption from grid fees for battery storage systems will be maintained until August 4, 2029. This exemption applies for 20 years after commissioning.

However, the investment decision for the construction of the battery storage systems must be made before the AgNes regulation comes into force. According to the Federal Network Agency, this is not expected to happen before January 1, 2027. Furthermore, the storage systems must be connected to the grid before August 4, 2029. With this regulation, the agency aims to create planning certainty for ongoing projects.

“We also want storage to contribute to the financing of the grid. We propose that capacity fees should only be paid after the expiration of the current special regulations,” Müller added.

The interim report envisions that new energy storage systems will pay a moderate capacity charge in the future. This will be analogous to the price that power generators will pay. Volumetric energy charges, on the other hand, are not planned for energy storage systems. Residential storage systems on the low-voltage grid are unaffected by the regulation; they will remain exempt from special grid fees moving forward.

Conversely, generating facilities will also be expected to contribute to grid financing. They will face a limited annual capacity charge. Initially, this is likely to range between €4 and €7 per kilowatt, per year. It is strictly intended for new installations, while existing plants will be granted grandfathering protection for 20 years from their initial commissioning. The Bundesnetzagentur estimates this will contribute up to €2 billion annually to grid financing. Plug-in balcony solar devices and prosumers will remain exempt from this specific charge.

For household customers, grid fees are not expected to change significantly—provided they are not prosumers. Households without their own generating facilities will pay a grid fee comprised of an annual base charge and a volumetric charge in cents per kilowatt-hour. For prosumers, such as households with their own photovoltaic systems, the base charge is set to be higher. Because they draw less electricity from the grid, they pay lower volumetric charges. The additional financial burden on prosumers due to this higher base charge is expected to be less than €100 per year. Plug-in solar devices are exempt from this new regulation, the Bundesnetzagentur noted.

“Those who generate their own electricity currently contribute less to financing the grid,” Müller explained. “But they too rely on the grid when the sun isn’t shining and the storage system is empty.”

Prosumers should bear a slightly greater share of the costs. “This is a matter of fairness. Otherwise, the rising costs would increasingly be borne solely by consumers without their own generation,” Müller continued.

A new model is also planned for large industrial consumers drawing over 100,000 kilowatt-hours. The Bundesnetzagentur wants to shift away from pricing based on consumed energy and peak demand toward pricing based on consumed energy and ordered capacity. Thus, large consumers will face a higher volumetric charge if they exceed their pre-ordered capacity.

The Bundesnetzagentur has pushed back its plans to introduce dynamic grid fees. The conceptual design requires extensive analysis, so the authority first wants to obtain further expert reports to determine the repercussions on redispatch, redistribution effects between market actors, and practical feasibility. “A regulation must trigger positive effects for the overall system and be practically implementable. A concrete concept is to be developed in 2027 and its effects examined,” the agency stated. However, the Bundesnetzagentur remains convinced that dynamic price signals could reduce the cost block for redispatch requirements, which amounted to a hefty €3 billion in 2025.

Dynamic grid fees are expected to arrive for battery storage systems from 2030 at the earliest, but ideally by 2033. If designed properly, this instrument is supported by battery storage operators because it promises additional revenue. Because of this, the Bundesnetzagentur plans to introduce it directly for all storage systems, rather than limiting it to new installations. For generators feeding into the grid, dynamic grid fees are slated for introduction from 2032 at the earliest, but ideally by 2035. Offshore wind farms will be exempt from this.

In the low-voltage sector, the authority plans a rapid and continuous development of a time-variable grid fee for residential photovoltaic storage systems and electric vehicles. The inclusion of consumers in the low-voltage grid via an opt-in model is conceivable, which is to be introduced as early as technically possible.

Additionally, the Bundesnetzagentur has slated for next year that it will work on rules for construction cost subsidies and guidelines for Flexible Connection Agreements (FCAs).

Furthermore, the AgNes determination will include new rules on the distribution of costs among grid operators themselves. The costs of upstream grids will be given greater consideration. However, additional costs due to renewables and special load demands will continue to be balanced out nationwide.

The new regulation of grid fees is necessary due to a ruling by the European Court of Justice. Accordingly, the existing Electricity Network Fee Ordinance will expire on December 31, 2028. The Bundesnetzagentur’s internal timetable now envisions publishing the first draft of the new determination in the coming weeks. Following the conclusion of the consultation phase, the AgNes framework determination should ideally be finalized by the end of the year, with implementation preparations beginning in 2027.

From the perspective of the Association of Local Public Utilities (VKU), the Bundesnetzagentur’s proposals meet the industry halfway on several important points. “This strengthens investment security,” said VKU Managing Director Ingbert Liebing. The protection of existing regulations for battery storage is seen as particularly positive, thereby preserving the protection of legitimate expectations.

“We take a critical view of the fact that the Bundesnetzagentur wants to stick to the introduction of dynamic grid fees,” Liebing noted. He argued that dynamic grid fees would intervene deeply in existing processes and involve a high implementation effort for grid operators. The VKU fears that false price signals could distort investments, and considers the gradual introduction of dynamic grid fees from 2030 to be “a very tight deadline.”

From pv magazine Germany.