​Germany's long-running uncertainty over grid fees is slowly lifting. On 27 May 2026, the regulator BNetzA published its preliminary views on the full grid fee overhaul, the Allgemeine Netzentgeltsystematik Strom (AgNes) framework. The regulator confirmed five major design choices that, taken together, represent a near-best-case outcome for battery energy storage.

The headline: a capacity fee of €4–7k/MW/year with no energy-based component, strong grandfathering for pre-2029 projects, and a dynamic fee design BNetzA expects to be net positive for storage. The final framework is expected by the end of 2026.

This is the fourth article in Modo Energy's series on German grid fees:

• What the regulator has proposed as a mechanism
• How financing tariffs may impact the business case
• Where batteries win and lose under dynamic pricing
• What the latest BNetzA update means for batteries and investors

For any questions or further information on this topic, contact till@modoenergy.com

Key takeaways

• Capacity fees confirmed at €4–7k/MW/yr, roughly 10% of residential capacity charges, with no energy-based component. Modo Energy’s Apr-26 modelling shows that even a worst-case €7k/MW/yr fee has an impact of around 0.5 percentage points IRR for a four-hour asset with COD in 2030.
• Grandfathering is strong and precisely defined. FID before the final AgNes decision secures 20 years of protection from commissioning date. FIDs paused since early 2026 can resume immediately.
• Dynamic grid fees are excluded from grandfathering, but BNetzA and independent studies confirm they will be net positive for storage.
• Generator fees of €4–7k/MW/yr apply to all generation above 30 kW from 2029. EEG projects can recover through higher auction bids. PPA projects face a harder pass-through on existing contracts, risking slower solar buildout.
• BNetzA commits to creating better frameworks for flexible connection agreements (FCAs) and grid connection fees (BKZ) from 2027, addressing the double-charging overlap between dynamic fees and operational constraints.

Capacity fees are low, and energy-based charges are off the table

The regulator has confirmed again that the full grid fee exemption for BESS will definitely end in 2029. But the resulting new fee is far from a worst-case scenario. From 2029 onwards, BESS will pay a financing-based capacity fee of €4–7k/MW/year, with no energy-based component. BNetzA's own calculation example puts the rolling five-year average at €5.38–5.65k/MW/yr.

This is approximately 10% of what residential customers pay in capacity grid charges. The fee draws on partial grid costs, the portion attributable to assets like BESS, not the full network stack.

At €4-7k/MW/year, the fee sits comfortably below the thresholds that break BESS project economics in most scenarios. It is not zero, but it is workable: Modo Energy’s Apr-26 modelling shows that even a worst-case €7k/MW/yr fee has an impact of around 0.5 percentage points IRR for a four-hour asset with COD in 2030.

The most consequential design question was always capacity versus energy. Energy-based fees act as a tax on every cycle, raising the minimum spread a battery needs to operate profitably. Previous Modo Energy modelling showed that a basic energy tariff of €66.50/MWh strips 4 percentage points from an unconstrained battery's 20-year IRR. Energy fees also distort operations directly: optimisers skip any cycle that does not clear the higher minimum spread, reducing annual cycle counts non-linearly. This results in flexibility that goes unused simply based on a market design choice - that has been avoided by just charging capacity-based fees.

Grandfathering is confirmed: FIDs can resume now

Germany's BESS pipeline stalled in early 2026, when BNetzA threatened to introduce grid fees even for operational assets. Investors refused to commit FIDs without certainty on which fee regime would govern 20 years of operation.

Today's announcement ends that uncertainty. BNetzA confirmed full grandfathering for projects meeting two conditions: commissioning before 4 August 2029, and FID before the final AgNes decision in late 2026. Protection runs for 20 years from commissioning, modelled explicitly on the §118 Abs. 6 EnWG framework that currently governs the existing BESS fee exemption.

FID is defined precisely: binding orders covering approximately 50% of total investment volume, irrevocable without material financial loss, plus a binding grid connection commitment. Speculative projects with no committed investment get no protection.

The practical implication is immediate: developers can now model and finance a fully protected 20-year business case. With the final AgNes decision expected by early 2027 at the latest, the window for qualifying FIDs is approximately six months. A run on FIDs is now possible, although moderate grid fees now mean even a slight delay in FID doesn’t break the business case.

Dynamic grid fees will come, and BNetzA expects them to pay BESS

BNetzA excluded dynamic grid fees from grandfathering. Protected projects will still face them when they apply. The reasoning is straightforward: dynamic fees are expected to benefit BESS, not burden it.

BNetzA cites independent studies confirming a net positive outcome for storage across virtually all regions, . Excluding a net revenue stream from grandfathering protection is logical rather than harmful.