Grid connection for battery storage in Germany: the queue, the maturity procedure and what an investor checks

More than 18,000 connection requests for battery storage reached German grid operators in 2025, together 573.5 gigawatts. In the same year 54.2 gigawatts were approved. Cells, inverters and containers can be bought; the place on the grid has to be granted. Whether that place exists, in what form and with what expiry date decides when construction starts, when revenue starts and how the tax planning of a direct investment works out.

In 2026 the rules shifted. The power plant connection ordinance (KraftNAV) with its deadlines expressly no longer applies to storage. Ruling Chamber 6 of the Federal Network Agency has said in four proceedings what a grid operator may and may not do. Since April the transmission system operators have allocated connections by project maturity rather than by date of receipt. And the grid package before the Bundestag wants to put the allocation into statute. This article sorts that out from the investor's perspective, step by step.

How long is the grid connection queue for battery storage really?

In 2025 there was one approval for roughly every nine requests, and just under a tenth of the requested capacity was approved. That is the result of the Federal Network Agency's second monitoring survey of all grid operators, published on 20 August 2026: 18,158 connection requests for storage at medium voltage and above, with 573.5 gigawatts of power and 1,583 gigawatt hours of energy capacity, three times as many applications as in 2024. There were 1,937 approvals covering 54.2 gigawatts, many of them for applications from earlier years. Counting only the applications filed in 2025, 1,468 of them received an approval covering 33.9 gigawatts.

The number of applications overstates demand. The agency itself points out that projects are often filed at several candidate sites at once to improve the odds of a connection; if a project receives several approvals, usually only one site is built. The more realistic yardstick is therefore the approvals, and even those are not yet a structure: an approval binds the grid operator, not the applicant. Actually in operation at the time of the survey were 1,292 storage units at medium voltage and above with 3.6 gigawatts and 6 gigawatt hours.

The transmission grid is where it is tightest. According to the concept paper of the four transmission operators from February 2026, they held storage applications for 211 gigawatts by the end of September 2025 and had already reserved 51 gigawatts. That is the order of magnitude the scenario framework of the network development plan expects only for 2037 (41 to 94 gigawatts). The paper states that almost all free connection points on the transmission grid are reserved for the next five years, and that the open applications would exhaust the available connections well into the 2030s.

A word on older figures: numbers of 700 gigawatts and more that circulated in 2025 rested on industry association estimates. The reliable series is the Federal Network Agency's: around 400 gigawatts requested and around 25 gigawatts approved in 2024, 573.5 and 54.2 gigawatts in 2025. What all these batteries do to revenues and price spreads is the subject of Germany's battery storage market: the numbers, the drivers, and why "now" has a date.

Is a storage project entitled to a grid connection?

Yes, but only to the grid as it stands and lies. Section 17(1) sentence 1 EnWG obliges grid operators to connect electricity storage installations, among others, on reasonable, non-discriminatory and transparent terms. Under subsection 2 they may refuse the connection insofar as they prove that it is impossible or unreasonable for operational, economic or technical reasons. The refusal must be reasoned in text form; in the case of a capacity shortage the reasoning must, on request, also state which expansion measures at what cost would be needed, for which the operator may charge up to half its costs. Subsection 2a puts storage on an equal footing with renewables: their connection priority does not apply against storage. It does not create a priority for storage itself.

What those sentences mean in practice was spelled out by Ruling Chamber 6 of the Federal Network Agency in 2026 in four special abuse proceedings under Section 31 EnWG, all brought by storage developers and all lost on the main issue. In decision BK6-25-325 of 30 March 2026 a distribution operator had rejected a battery because the power draw would depress voltage in the 110 kV grid beyond permitted limits; the necessary expansion would take eight to ten years. The chamber held the refusal lawful, denied any duty to hand over grid data for the applicant's own calculations, and denied any duty to propose a flexible connection agreement on the operator's own initiative; Section 17(2b) EnWG merely gives the operator an option.

Decision BK6-25-287 of 4 May 2026 concerned the transmission grid. The operator had stated that capacity was overbooked at all sites, that a connection at the nearest substation would probably not be possible before 2030 and that it would switch to a maturity-based procedure. The chamber saw no breach: there is no claim to an individual grid expansion, expansion follows the overall need alone, and Section 17(1) EnWG prescribes no particular allocation procedure. A change of procedure is permissible as long as existing applications are carried over and payments already made are credited.

Decision BK6-25-512 of 6 May 2026 concerned a substation without a free switchgear bay whose extension is not due until 2037. The refusal was not abusive. Two side remarks matter more to investors than the outcome: an application only acquires its rank once it is complete, and expired letters of intent for land security make it incomplete; the responsibility for that lies with the applicant. And a rank once acquired is extinguished neither by a refusal for lack of capacity nor by the applicant staying silent after the refusal. If capacity is freed later, for instance because another party hands back its approval, the old order continues to apply.

Decision BK6-25-546 of 9 September 2026, finally, upheld the refusal of a 380 kV connection because the land at the substation is needed for measures confirmed in the network development plan. The operator lost on one point: a flat assessment fee of EUR 50,000 that is neither refunded nor credited against anything breaches Section 17 EnWG. The grid compatibility assessment is one of the operator's core tasks, and the applicant faces it as a monopolist. A realisation deposit that is credited on realisation and otherwise refunded remains permissible.

There has been no statutory processing deadline for storage since 24 December 2025. The ordinance amending the power plant connection ordinance (Federal Law Gazette 2025 I No. 368) clarifies in Section 1(1) sentence 2 KraftNAV that the ordinance does not apply to energy storage installations. That removes, for storage, the deadlines that apply to power plants of 100 megawatts and more: a reply within two weeks, assessment results three months after the advance payment, a contract within twelve months. What remains, in the chamber's reading, is a duty to communicate within reasonable periods: the applicant must learn as promptly as possible whether a connection at the desired point is feasible at all and roughly how long it will take. How a request proceeds formally and what a commitment is in legal terms is described in Grid connection, easement, building rights: how to tell whether a direct investment has truly secured its site.

How does the maturity procedure on the transmission grid work?

Since 1 April 2026 the four transmission system operators have allocated connection capacity for storage and large consumers in fixed cycles by project maturity, no longer by date of receipt. The basis is their joint procedure documentation, most recently in the version of 16 June 2026. Each cycle has three phases: a three-month information and application phase in which the operators publish free capacity and applications must be complete by a cut-off date; a cluster study of around five months in which all applications of a cycle are checked, scored and assigned to sites together; and an offer phase of a little over two months. In the first cycle the cut-off date was 30 June 2026, feedback is promised by 30 November 2026, offers can be accepted until 31 December 2026 and unaccepted capacity is reallocated once in January 2027. According to one transmission operator, the first cycle drew 347 applications with 156.4 gigawatts of draw capacity.

The application costs a flat fee of EUR 50,000, due on the cut-off date; without receipt of payment the application is deemed not filed. Whoever fails the minimum requirements is excluded immediately and gets half back. Whoever is admissible but receives nothing in the cycle may compete in the next one without a new fee and may file additional evidence; nothing is refunded in that case. The minimum requirements include an exclusivity declaration from the landowner or a preliminary contract binding for at least seven months from the cut-off date, a current land register extract, a technical concept on the operator's forms and a commercial register extract. If capacity suffices for all admissible applications, that is enough for a reservation. Only when a site is oversubscribed do points decide.

Whoever receives an offer learns the capacity, the connection point and a non-binding earliest connection date, plus their own score and that of the last project still considered at the site. The offer is accepted within one month by paying a realisation deposit of EUR 1,500 per megawatt. On realisation it is credited in full against the connection charge (Baukostenzuschuss) and forfeited only if the project fails for reasons within the applicant's sphere. The Federal Network Agency regards this level as not unreasonable in its answers on the connection of storage; it derives it from the EUR 1,000 per megawatt fee the power plant ordinance has known since 2007. The offer may also be for a reduced capacity if the grid calculation for the downstream grid shows congestion; the cut then hits the projects with the lowest maturity first.

With the reservation comes the duty to keep pace. Within three months a negotiation schedule for the connection construction agreement and the grid connection agreement is agreed; if there is no agreement, the operator presents a binding schedule that must be accepted within 14 days, otherwise the reservation lapses. The contract then contains a realisation schedule with dates for permits and land security. The operator may cancel the reservation if these schedules are not kept, if basic parameters of the project change materially, if false statements were made in the application or if subsequent changes would have pushed the original score below the threshold. The connection charge itself is due in three tranches: 30 to 50 percent on signing, 30 to 50 percent eighteen months later or at the start of construction, 20 percent on commissioning of the connection.

Legally the procedure so far rests on Section 17(1) EnWG and the operators' discretion, which the ruling chamber has confirmed. Confirmation by the Federal Network Agency, which European law envisages, had not been issued as of 6 November 2026; the grid package would make it mandatory by 1 January 2027. Applications from the old queue were carried over into the new procedure, fees already paid were credited, and approvals already granted remain valid.

What applies in the distribution grid, where most storage is connected?

There is no uniform procedure there, and in practice the order of receipt still counts. 17,775 of the 18,158 requests of 2025 went to distribution operators, with an average approval of 14 megawatts; that is the scale at which direct investments take place. The transmission operators do recommend that distribution grids introduce a maturity procedure of their own so that applicants do not migrate to the lower grid levels. That is not binding, and procedures differ from operator to operator.

Three rules nevertheless apply everywhere, because they follow from Section 17 EnWG and the 2026 decisions. First, a rank in the queue arises only with a complete application; whoever lets land security evidence expire falls back without the operator having to warn them. Second, a rank once acquired is not extinguished by a refusal for lack of capacity; whoever was refused stays on record for the case that capacity is freed, and should therefore not withdraw the application but keep interest and evidence current. Third, the operator may change the allocation procedure as long as capacity has not been bindingly allocated; a place in the first-come-first-served queue is no vested right against a future points system.

A battery needs capacity in both directions. The Federal Network Agency puts it this way: because of their dual role, battery storage installations need connection capacity for both injection and withdrawal and may have to take part in separate allocation procedures for each side. A physical connection does not yet mean an allocation of the requested capacity; that sits in the grid connection agreement. For investors this means that the capacity in a commitment must be read separately for draw and feed-in, and that a commitment a solar park obtained for its feed-in does not cover a battery at the same point. How park and battery can share a connection is shown in Co-located vs. stand-alone: which gives the better risk structure.

On costs the position has been clearer since September 2026. A fee merely for assessing the request may not be charged; a realisation deposit may, provided it is credited on success and refunded on failure. The connection charge under the capacity price model may be levied from storage by distribution operators since the Federal Court of Justice decision of 15 July 2025 (EnVR 1/24); its mechanics and order of magnitude are covered in Grid fees for battery storage: the exemption until 2029 and the AgNeS reform. A flexible connection agreement limiting the draw capacity can, in the agency's view, reduce the charge.

What would the grid package change for storage connections?

It writes into law what the transmission operators already do and brings the distribution grid along; it has not been adopted yet. The government draft (Bundestag printed paper 21/7866) cites grid expansion times of eight to twelve years in its reasoning and roughly estimates that only 20 percent of connection requests from 135 kilowatts upwards are realised. Six provisions matter for storage projects:

• Section 17a EnWG draft: the transmission operators submit their procedures to the Federal Network Agency for confirmation by 1 January 2027; the reasoning expressly names reservation fees and even an auction of capacity as permissible designs.
• Section 17b EnWG draft: seven criteria by which connection requests may be prioritised or capacity held back, from system security via the scenario framework to site dependency; a discretionary rule that distribution operators may adopt. The Bundesrat wanted to add maturity as an eighth criterion; the federal government rejects that because it is a procedural question (printed paper 21/8299, No. 14).
• Section 17c EnWG draft: grid operators must publish available connection capacity at the transformer levels to high and medium voltage on a map updated monthly, with no legal claim to the capacity shown; from 2028 there is a non-binding online enquiry from 135 kilowatts upwards including a cost estimate.
• Section 17d EnWG draft: two months after receipt of a request the operator must inform the applicant about status and further handling, and every three months thereafter. That is the first deadline for storage since the end of the power plant ordinance, even if it only concerns information, not the decision.
• Section 17f EnWG draft: distribution operators develop joint rules for reserving capacity from 135 kilowatts upwards; reservations are time-limited in stages and tied to project progress, according to the reasoning about six months per stage and as a rule no longer than two years, and a fee is permissible.
• Section 17(2a) EnWG draft: at an existing connection point an additional battery may not be refused for lack of capacity if a flexible agreement leaves the previous maximum capacity unchanged. That is the rule for the battery at the solar park covered by Overbuilding the grid connection: what more module capacity than connection capacity means for yield and investors and Retrofitting battery storage at a solar park: what does the MiSpeL ruling change?.

In its opinion the Bundesrat calls the connection backlog the bottleneck of the energy transition and considers the list of criteria insufficient to decide between equally mature projects; the federal government will examine further specification. The Bundestag debated the draft at first reading on 24 September 2026 and held a hearing on 7 October. It was not on the agenda of the sitting week of 4 to 6 November; no date for the final reading had been documented as of 6 November.

What does a year of waiting cost the investor?

In our calculation around 5 percent of present value per year, considerably more with falling revenues, and in the worst case the investment deduction. The model is deliberately simple: one megawatt of storage with two hours of capacity, a gross revenue of EUR 69,000 per megawatt and year from our storage duration model with 2025 day-ahead prices, 30 percent operating costs, 15 operating years, a 5 percent discount rate. If commissioning slips by a year, the operating life stays the same, but every euro arrives a year later. If one additionally assumes that revenues per megawatt fall by 3 percent a year as more batteries are built, the delayed plant starts in a worse market year.

The first year costs 4.8 percent of present value, 7.6 percent with the decline; three years cost 13.6 and 21.2 percent respectively. For a direct investment a second mechanism comes on top, and it is not linear. Whoever has formed an investment deduction (Investitionsabzugsbetrag, IAB) must have invested by the end of the third financial year following the year of deduction; a battery whose connection slips beyond that limit loses the deduction retroactively. With a deduction of EUR 100,000 and a 42 percent marginal rate that means EUR 42,000 of back tax plus interest under Section 233a of the Fiscal Code at 0.15 percent per month from the 15th month after the year of deduction, around EUR 1,700 for 27 interest months in our example. The deadlines are explained in Forming the IAB now: which tax deadlines and time windows count in 2026/2027, the consequences in Reversing the IAB: what happens if you don't invest, deadlines, interest, ways out. What matters, then, is that the connection date in the reservation fits the tax year of the deduction, with a margin.

The third item is capital tied up before the first revenue. In the maturity procedure the application fee of EUR 50,000 per project and the deposit of EUR 1,500 per megawatt fall due before any contract exists; for a 10 megawatt project that is EUR 6,500 per megawatt, just under a tenth of a gross annual revenue. The first tranche of the connection charge becomes due with the grid connection agreement, often years before commissioning. In a project calculation these amounts belong with their dates, not inside a lump-sum line.

How can you tell how far the grid connection of a storage project really is?

From documents with a date, a capacity and a consideration, not from the phrase "grid connection secured". Between a first enquiry and a built connection lie five stages, and each can be evidenced:

1. Non-binding information: a grid operator has stated on enquiry that capacity might be available at the desired point. That is information, not a rank and not a reservation.
2. Application filed: there is a complete connection request with an acknowledgement of receipt. Check the date of completeness, the rank or cycle communicated, the requested capacity separately for draw and feed-in, and whether the fee has been paid.
3. Offer or reservation: the operator has named capacity, connection point and a non-binding earliest connection date. Check the acceptance deadline, payment of the deposit, the time limit of the reservation, conditions from a negotiation or realisation schedule, and whether the capacity was reduced or tied to a flexible agreement.
4. Grid connection agreement or connection construction agreement: capacity, connection point, dates and connection charge are fixed by contract, the first tranche has been paid. Only from here on is the connection secured in the legal sense.
5. Connection built and in operation: the switchgear bay or substation exists, the plant is registered in the core energy market data register with its grid connection.

A look at the operators' maps is worthwhile too. Since spring 2026 the four transmission operators have published maps showing the connection situation at their substations; some show an earliest connection from 2032 for individual sites, one names 2029 for new project starts and a process duration of three and a half to six and a half years to a finished connection. The maps are non-binding, but they show whether a date in an exposé fits the grid situation at the site. The grid package would make such maps mandatory and monthly for the upper transformer levels.

Red flags are easy to name: a connection "under review" without rank or cycle; a commitment issued for a solar plant and not for the battery; a commitment for a different site than the one in the exposé, because the project was filed several times; land security evidence whose term has expired; an assessment fee that was paid and is credited nowhere; and a revenue start in the model that lies before the earliest connection date in the reservation.

Which questions should investors ask about a battery's grid connection?

• At which stage is the grid connection: information, complete application, reservation, contract or built? Which document proves that, with what date?
• What capacity is requested or committed, separately for draw and feed-in? Does it match the storage capacity in the exposé?
• On the transmission grid: in which cycle of the maturity procedure is the application, what score did it achieve and what score did the last project considered at the site have?
• In the distribution grid: what rank does the application hold, since when has it been complete and when does the land security evidence expire?
• Has the deposit been paid? Is it credited against the connection charge? Were assessment fees paid, and are they refunded or credited?
• Which deadlines are in the reservation, the negotiation schedule and the realisation schedule, and when does the reservation lapse if they are not met?
• Was the capacity reduced or tied to a flexible connection agreement? With what limit, in which hours, until when?
• How high is the connection charge under the operator's price sheet, when are the tranches due and do they appear with dates in the calculation?
• Which connection date is in the reservation or contract, and does it fit, with a margin, the three-year window of the investment deduction?
• What happens to the investment if the connection comes a year later: who bears the cost, is there a right of withdrawal?

General checks for any provider are set out in How to tell a trustworthy provider of energy direct investments; the typical risks of a storage investment are classified in Risks in BESS direct investments, and how they are structurally addressed.

How we check the grid connection of a storage project

For every battery storage project we present to investors, we first assign the grid connection to one of the five stages and ask for the document behind it: the acknowledgement of receipt with rank or cycle, the reservation offer with deposit and deadlines, or the grid connection agreement with the connection charge. We read the capacity separately for draw and feed-in, check the term of the land security evidence and compare the connection date with the operator's map and with the revenue start in the model. For investors with an investment deduction we place the date next to the three-year window and calculate what a delay would cost. Projects whose connection exists only as information or as an incomplete application we do not present as ready for investment.

We give no return guarantees. We show which figure rests on which document. What a battery storage system is as a direct investment overall is set out in Investing in battery storage: the options at a glance. That is exactly what we check with you in a non-binding initial consultation, ideally on the basis of a specific exposé.