Until now, anyone connecting a battery to the grid before August 4, 2029, has enjoyed a 20-year exemption from grid fees. But this privilege is coming to an end. The regulatory authority has made it clear: a permanent exemption from grid fees for battery storage is no longer sustainable.

This is causing concern. Many project developers are now rushing to connect their storage systems before August 2029 to secure the exemption. The fear: after this date, grid fees could significantly undermine the business case.

However, what's coming isn't simply a “return to costs,” but an entirely new grid fee system that will establish new rules for storage.

The Federal Network Agency is currently publishing new position papers step by step, which are gradually but clearly outlining the future regime. What’s clear: grid fees will no longer just fund grid expansion, but will also be used to actively steer flexibility – including storage.

This opens up new opportunities. In the future, storage can optimize not only for market prices but also for grid value. Those who are flexible enough will benefit from the system, rather than suffer from it.

This article is part of a series on future grid fees for German batteries:

• What the regulator proposes so far as a mechanism
• How financing tariffs may impact the business case
• How dynamic tariffs can become a revenue stream - depending on location

1. Key Questions for Battery Developers

Will batteries have to pay grid fees after 2029?

According to the Federal Network Agency – yes. The BNetzA has made it clear that the current exemption will not remain in place indefinitely. As the share of battery storage in the power system grows, they too will be expected to contribute to grid costs.

However, the final decision is still pending: possible transitional arrangements or methodological adjustments are still being discussed.

What grid fees will likely apply to standalone batteries?

From 2029, operators should expect a new, much more complex fee system. A three-part model is planned:

• Grid connection fee (BKZ) remains. As before, this is a one-off fee when connecting to the grid.
• Financing tariffs will be split into:
• Capacity fees, based on the maximum connection capacity. There will be a choice component: operators can decide how much capacity to “reserve” and pay for accordingly.
• Energy charges, based on actual energy flow – but only on the battery’s net self-consumption, essentially RTE losses (the so-called netting tariff). If more energy is used than the chosen capacity allows, a penalty surcharge applies.
• Dynamic grid fees will be introduced as a new, separate element and could be a game-changer:
• These tariffs apply to every kWh charged or discharged.
• Crucially: they can also be negative. Batteries that charge or discharge in a grid-supportive way could actually generate revenue instead of costs.

What do the new grid fees mean for the business model of battery storage?

The good news: the new fee system doesn’t have to be a burden. For some projects, the changes could even open up new sources of income.

The actual impact depends mainly on two factors.

• How high will the capacity and energy charges ultimately be?
• How much can be earned by optimizing around the dynamic tariffs?

In scenarios with low financing charges and for batteries with high locational value (e.g., in areas with grid congestion), battery storage could even end up in a better position than today.

On the other hand, without the uplift from dynamic tariffs, revenues could be 3–10% lower, depending on the level of grid fees applied.

2. Financing Fees Will Increase OpEx

What is the logic behind netting tariffs and how do they work?

The basic principle: Only the battery’s own consumption (RTE losses) is subject to financing grid fees, not all energy charged or discharged. This puts storage on par with other consumers.

The financial impact mainly depends on the energy charge and how it develops in the future: At the highest and high voltage levels, grid fees are forecast to remain largely stable until 2030. However, it is uncertain whether the government will continue current relief measures in the long term.

• Without subsidies, the price for 2026 would be around €66.50/MWh. If grid fees stay stable, we can expect a similar price in the future.
• With subsidies, the price is closer to €28.60/MWh.

For a 2-hour battery with 86% RTE, 2 cycles/day, and operating as a balancing reserve, this means:

• Approx. 150 MWh/MW/year as the battery’s self-consumption
• €4.3k–10k/MW/year in grid fees, depending on the grid fee level
• This translates to about 3–8% lower revenues.