Grid-fee exemption for storage under §118(6) EnWG

Anyone planning a battery storage system asks a regulatory question early on. Does the system qualify for the grid-fee exemption under §118(6) of the Energiewirtschaftsgesetz (EnWG, Energy Industry Act), and what follows from that for construction and operation? The answer turns on a deadline, a condition, and an ongoing reform that reshapes the framework around the exemption without touching the exemption itself.

What the exemption covers

Under §118(6) EnWG, newly built electricity storage systems that were created after 31 December 2008 and commissioned within 18 years of 4 August 2011 are exempt from grid access fees for 20 years from commissioning. The exemption applies to the energy drawn to be stored. It is tied to a specific mode of operation, not to the system as such.

The deadline: 4 August 2029

The 18-year window runs from 4 August 2011 and closes on 4 August 2029. What counts is commissioning, not the order date and not the start of construction. A system that goes live after that date falls outside the exemption even if planning and contract were finished long before. For a project that still has to meet the deadline, the whole chain matters: load-profile analysis, feasibility study, Lastenheft (specification), tendering, construction and acceptance. Every delay in any one of these steps shortens the buffer before the cut-off date.

The condition: drawing from and feeding back into the same grid

The law grants the exemption only where the electricity drawn for storage comes from a transmission or distribution grid, and the energy recovered on discharge is fed back, with a time delay, into that same grid. A system that draws energy from the grid but delivers it elsewhere, or in a different form, does not automatically meet the condition. Systems that use the stored energy to produce hydrogen by electrolysis, or gas made from it, are excluded from the exemption altogether. For a standard commercial storage system that takes grid energy and returns it to the same grid with a time offset, the condition is normally achievable. Whether a specific system meets it is checked in the technical planning.

What this means for a commercial storage system

The exemption reduces the grid access fees that would otherwise apply to the energy drawn from the grid. It does not replace the assessment of other cost items such as taxes, levies or metering point operation, and it changes nothing about the obligation to register in the Marktstammdatenregister (core energy market data register) or about the technical connection rules under VDE-AR-N 4105 and VDE-AR-N 4110. An operator should treat the exemption as one of several factors that together shape a system’s economics, not as a standalone benefit.

AgNes: what changes and what does not

Since 2025 the Bundesnetzagentur (Federal Network Agency, BNetzA) has been working on a reform of the general electricity grid-fee system, known as AgNes. One aim is to bring storage systems and generation plants into the cost-sharing that today mostly falls on consumption. In a press release of 27 May 2026 the agency set out its interim position and stated that the fee obligation for existing storage systems should only start once the special rules under §118(6) EnWG expire, where they apply. That confirms the existing framework rather than replacing it. For newly built storage systems, the interim position foresees a moderate capacity-based fee; home storage systems on the low-voltage grid are meant to keep their exemption.

It matters to separate what is decided from what is proposed. The wording of §118(6) EnWG itself is decided. The AgNes interim position is proposed and not yet a binding determination. The formal consultation on the full draft was announced for summer 2026, with a final determination targeted for the end of 2026. Until then, exactly how new rules will take effect from 2029 remains open. A project being planned today should treat the §118(6) EnWG deadline as a fixed part of the framework, and watch the AgNes process as it develops rather than anticipate its outcome.

Practical steps before placing an order

In a typical commercial project, the chain from load-profile analysis through feasibility study, specification, tendering, construction and acceptance takes several months to over a year, depending on system size, the grid connection situation and how busy the installers involved are. Anyone who starts planning only shortly before the deadline risks a single delayed step, a slow reply from the grid operator or a longer component lead time, pushing commissioning past 4 August 2029. Scheduling therefore belongs in the feasibility study from the start, not in the later construction phase.

Beyond the deadline itself, an operator should establish early whether the planned mode of operation actually meets the §118(6) EnWG condition, in particular the delayed feed-back into the same grid the energy was drawn from. That check is a technical question to settle with the grid operator. It should be recorded as a requirement in the specification, so it can be demonstrated at acceptance rather than questioned afterwards.

Whether a planned system can realistically meet the deadline, and how the commissioning date and the tendering process relate to each other, is what a feasibility study establishes before a specification is written. As of September 2026.

Sources

1. §118(6) EnWG, gesetze-im-internet.de
2. Bundesnetzagentur, "Bundesnetzagentur stellt aktuelle Überlegungen zur Reform der Netzentgeltsystematik Strom vor" (press release, in German), 27 May 2026
3. Bundesnetzagentur, AgNes determination proceeding (in German)