Standalone battery storage stations that operate without support get a Final Connection Offer in Greece through a dedicated call of the Ministry of Environment and Energy (ΥΠΕΝ/ΓΔΕ/28255/1143/2025, ΦΕΚ Β΄ 1248): up to 3,800 MW on ΑΔΜΗΕ's transmission system and 900 MW on ΔΕΔΔΗΕ's distribution network, split into project groups and, for the largest share, by Region. Applications were due by 31 October 2025. The order is set by a ranking decision of the Minister, and the operators grant offers in that order.
Last updated: · Also in Greek: Merchant μπαταρίες (BESS): πώς παίρνουν Οριστική Προσφορά Σύνδεσης
| What | Rule | Provision |
|---|---|---|
| Total cap on Final Connection Offers | 3,800 MW of maximum injection capacity from ΑΔΜΗΕ and 900 MW from ΔΕΔΔΗΕ | ΥΠΕΝ/ΓΔΕ/28255/1143/2025, art. 2(1) |
| Which operator | ΔΕΔΔΗΕ for stations up to and including 10 MW, ΑΔΜΗΕ for larger ones | same decision, art. 2(1), as amended by Β΄ 5165/2025 |
| Application deadline | 31 October 2025 | same decision, art. 3(2), as amended by Β΄ 5165/2025 |
| Technical minimum | batteries only; injection capacity of at least 0.5 MW; usable capacity of at least two hours; round-trip efficiency of at least 80% | same decision, arts. 3(1) and 4(1) |
| Financial capability | a loan pre-approval or own funds for the whole cost, at a reference cost of EUR 200 per kWh of guaranteed capacity; letters of intent are not accepted | same decision, art. 3(1) and (2), as amended by Β΄ 5165/2025 |
| Participation guarantee | EUR 200,000 per MW above 10 MW, EUR 50,000 per MW up to 10 MW (EUR 100,000 per MW without financing evidence), valid for at least two years | same decision, art. 3(2)(ιγ), as amended by Β΄ 5165/2025 |
| Performance and operation guarantee | EUR 200,000 per MW above 10 MW, EUR 50,000 per MW up to 10 MW; halved after three years of operation and returned after six | same decision, art. 7(2), as amended by Β΄ 5165/2025 |
| Readiness declaration | within 18 months of accepting the Final Connection Offer | same decision, art. 7(1) |
| Concentration limits | 250 MW per natural or legal person with its connected companies, 50 MW on the distribution network, and 500 MW in total of batteries until the end of 2029 | same decision, art. 5, as amended by Β΄ 5165/2025 |
| Support | none: the stations receive no operating support and do not take part in support tenders | same decision, arts. 1(3) and 3(2)(θ) |
This table as data: CSV · JSON · free to reuse with attribution (CC BY 4.0)
The call is for holders of standalone battery storage stations that, where required, hold a valid storage licence and have already filed a complete request for a Final Connection Offer with the competent operator. They also needed an environmental permit where one applies, a site secured for at least ten years, and proven financing. Excluded are stations that already have a Final Connection Offer, stations selected in a support tender, storage added to a renewable station behind a common connection point (art. 11Γ(5) of Law 4685/2020), and conversions of conventional units to storage (art. 3(1)).
For a station exempt from environmental permitting, the request for the exemption certificate was enough. The request then takes its place in the queue with a date twenty days after filing with the environmental authority or with ΔΕΔΔΗΕ, whichever is later. By the signature of the Connection Agreement, the environmental authority's answer is submitted if it has been issued, and a negative answer cancels the offer (art. 3(2)(ε)).
Each application named the group or groups it wished to join. The groups and their maximum capacity:
| Group | Which stations | Maximum capacity (MW) |
|---|---|---|
| ΕΣΜΗΕ Α1΄ | a binding bilateral agreement of at least eight years with an energy-intensive industry, for the whole capacity; station above 10 MW | 500 |
| ΕΣΜΗΕ Α2΄ | a binding bilateral agreement of at least eight years with a business; station above 10 MW | 100 |
| ΕΣΜΗΕ Α3΄ | the holder has an aggregator (ΦοΣΕ) licence, or is wholly owned by an aggregator, representing at least 100 MW of renewables; station of 10 to 100 MW and at most 10% of the renewables it represents | 300 |
| ΕΣΜΗΕ Β΄ | stations in a Core Lignite Phase-out Zone, up to 100 MW per Core | 250 |
| ΕΣΜΗΕ Γ΄ | all other transmission-connected stations, with a cap per Region | 2,650 |
| ΕΔΔΗΕ Α΄ | distribution-connected stations above 5 MW | 350 |
| ΕΔΔΗΕ Β΄ | distribution-connected stations of 1 to 5 MW | 150 |
| ΕΔΔΗΕ Γ΄ | distribution-connected stations below 1 MW | 150 |
| ΕΔΔΗΕ Δ΄ | a binding bilateral agreement of at least eight years with a business; station up to and including 10 MW | 250 |
This table as data: CSV · JSON · free to reuse with attribution (CC BY 4.0)
In the groups with a bilateral agreement, the injection capacity may not exceed the business's maximum annual consumption capacity over 2021 to 2024, including consumption covered by self-generation (art. 6(2) and (3), as amended by Β΄ 5165/2025). The 2,650 MW for ΕΣΜΗΕ Γ΄ comes from the September 2025 amendment; the original text of art. 6 said 2,550 MW, although the table by Region already added up to 2,650.
| Region | Maximum capacity, ΕΣΜΗΕ Γ΄ (MW) |
|---|---|
| Eastern Macedonia and Thrace | 250 |
| Central Macedonia | 400 |
| Western Macedonia | 425 |
| Thessaly | 250 |
| Epirus | 100 |
| Western Greece | 150 |
| Central Greece | 300 |
| Peloponnese | 400 |
| Attica | 100 |
| Crete | 200 |
| South Aegean (interconnected Cyclades) | 25 |
| Ionian Islands | 50 |
This table as data: CSV · JSON · free to reuse with attribution (CC BY 4.0)
In Eastern Macedonia and Thrace, Central and Western Macedonia, Thessaly and Central Greece, 100 MW of each cap goes only to stations connecting to an HV/MV substation of the transmission system, excluding substations serving the distribution network (art. 6(2)). Capacity left unused in a Region moves to the Region with the largest cap. For Crete, the Cyclades and the Ionian Islands, the remainder goes to the ΔΕΔΔΗΕ groups on the same islands (art. 2(2), as amended by Β΄ 5165/2025).
After the deadline, a three-member Committee checks the requests with the operators and proposes to the Minister a ranking list for each group, with projects covering up to twice the capacity available. The ranking is issued by decision of the Minister (art. 11Δ(7) of Law 4685/2020), and the operators grant offers in its order (art. 6(1), as amended by Β΄ 5165/2025). For the transmission groups the order is set in three steps (art. 6(4)):
The saturated Peloponnese system has its own rule: up to 200 MW go to stations with at least four hours of capacity within 15 kilometres of a ΚΥΤ, ranked by guaranteed capacity, and another 200 MW to stations above 70 MW, by distance from the substation (art. 6(5)). ΑΔΜΗΕ works through the lists in the order Β΄, Γ΄, Α1΄, Α2΄, Α3΄ (art. 6(6)). A request that would need a new substation or ΚΥΤ not under construction or without a suitability approval is removed from the list (art. 6(1)).
On ΔΕΔΔΗΕ's network the order is set separately for each substation in Annex I of the decision and for the operating substations on Crete, the Cyclades and the Ionian Islands, by the order of complete request. Each substation takes up to 25 MW in total and each transformer up to 15 MW: at most one station of 5 to 10 MW and up to five stations below 1 MW (art. 6(7), as amended by Β΄ 5165/2025).
The deadline was extended twice: first to 30 September 2025 (Β΄ 2886/2025) and finally to 31 October 2025 (Β΄ 5165/2025). Within twenty days of the deadline, the operators publish a list of all complete requests with their completeness date (art. 3(4)). ΑΔΜΗΕ has posted the list of complete storage requests pending at 31 October 2025: 480 requests, 27.5 GW of injection capacity. The complete requests, in other words, exceed the 3,800 MW available on the transmission system many times over. The next steps are the Minister's ranking decision and then, in its order, the Final Connection Offers. The figures are tracked on the page Energy storage in Greece: the licensing pipeline in numbers.
A holder who receives a Final Connection Offer replaces the participation guarantee with a performance and operation guarantee within three months. Otherwise the participation guarantee is forfeited (art. 8(2)). A holder who withdraws after joining the priority list and before receiving an offer loses 25% of the participation guarantee, unless the withdrawal is made to respect the concentration limits (art. 8(3)). The guarantee is returned, on the other hand, to anyone not included in the lists or who does not accept the offer granted.
If the technical requirements, the concentration limits or the implementation obligations are breached, or false information is given, the guarantee is forfeited to the Special Renewables Account and the operator deactivates the connection until compliance is restored (art. 8(1)). After the offer, the storage licence may not be amended in a way that worsens the ranking data or increases the injection capacity; otherwise the offer is cancelled (art. 3(6)).
The call is not the only route. Storage is also examined under the priority framework of ΑΔΜΗΕ and ΔΕΔΔΗΕ, Laws 5299/2026 and 5325/2026 added separate tracks for storage combined with solar PV and for self-consumption, and stations from ΡΑΑΕΥ's tenders have deadlines of their own. They are explained in the guide to the priority groups and the battery storage permitting guide.
For each station, MitOS keeps the letters of guarantee and their deadlines together. Your permitting path is derived from the law itself: change one project fact and the whole path re-derives, every requirement carrying its legal citation. A rolling 90-day timeline and a live flag feed surface what is due and what is at risk before it costs you the project.
A short demo on the real stages of your projects, with Greek law already built in.
No. The deadline was 31 October 2025 (ΥΠΕΝ/ΓΔΕ/28255/1143/2025, art. 3(2), as amended by Β΄ 5165/2025). New storage projects follow the other routes of the priority framework.
For a station above 10 MW, EUR 200,000 per MW of injection capacity, first as a participation guarantee and, after the offer, as a performance and operation guarantee. For a station up to 10 MW, EUR 50,000 per MW, or EUR 100,000 per MW if no financing evidence was filed with the application. The performance guarantee is halved after three years of operation and returned after six.
Up to 250 MW through the call, and 50 MW on the distribution network. In total, Final Connection Offers for a group's batteries, standalone or combined with renewables, other than the stations of art. 10(11Α) of Law 4685/2020, may not exceed 500 MW until the end of 2029. Rights under tolling or revenue-sharing agreements count too (art. 5, as amended by Β΄ 5165/2025).
The readiness declaration is due within 18 months of accepting the Final Connection Offer (art. 7(1)).
This page summarises provisions for information and does not replace legal or technical advice on a specific project. The decisions were checked against the original gazette on 20 October 2026. Only the official publication in the ΦΕΚ and the announcements of the Ministry and the operators are authoritative.
Permitting energy projects is a labyrinth. MitOS is the thread.
