​Anyone connecting a battery to the grid before August 4, 2029, currently enjoys a 20-year exemption from grid fees. But this privilege is about to expire. The regulator has made it clear: a permanent exemption from grid fees for battery storage is unsustainable.

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

But what's coming is not simply a “return to grid fees,” but a completely new fee system that will set fresh rules for storage.

The Federal Network Agency is currently publishing new position papers step by step, making the future regime increasingly clear. What’s certain: grid fees will no longer just fund grid expansion, but specifically incentivize flexible behavior—including storage assets.

This opens up new opportunities. In the future, storage will be able to optimize not just for market prices, but also for grid value. Those flexible enough will benefit from the system, instead of being penalized by 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 the current exemption will not remain in place permanently. As batteries make up a growing share of the power system, they too will be expected to contribute to grid costs.

However, a final decision is still pending: possible transitional rules or changes to the methodology are still being discussed.

What kind of grid fees will standalone batteries likely face?

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

• Grid connection fee (BKZ) remains. This is still a one-off payment when connecting to the grid.
• Financing tariffs will be split into:
• Capacity charges, based on maximum connection capacity. There will be a choice component: operators can choose which capacity to “reserve” and pay accordingly.
• Energy charges, based on actual energy flows—but only on the battery’s net self-consumption, essentially its RTE losses (the so-called balancing tariff). If more energy is consumed than the chosen capacity allows, a penalty surcharge applies.
• Dynamic grid fees will be introduced as a separate new element and could be a gamechanger:
• 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 generate revenues, not just 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 additional revenue streams.

The actual impact depends mainly on two factors.

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

In scenarios with low financing charges and batteries with high locational value (e.g. in grid-constrained areas), storage could actually end up better off than today.

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

2. Financing Charges Will Raise OpEx

What’s the logic behind balancing tariffs and how do they work?

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

What this means financially depends mainly on the energy charge and how it develops in the future: At the high and extra-high voltage level, grid fees are forecast to remain largely stable until 2030. However, it’s uncertain whether the government will continue to subsidize these reductions long term.

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

For a 2h battery with 86% RTE, two cycles per day, and providing reserve, this means:

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