Storage does not follow the same road as a renewable plant. It has its own licence, its own capacity threshold, and two entirely different routes depending on whether the station stands alone or accompanies generation. Here is the distinction, with the provision behind each.
Last updated: · Also in Greek: Αδειοδότηση σταθμού αποθήκευσης
| What | Rule | Provision |
|---|---|---|
| Storage licence for a standalone station | required, unless legally exempt | Law 4001/2011, art. 132E(1), added by Law 4951/2022, art. 70 |
| Exemption from the storage licence | injection capacity below 1 MW | same article, (2) |
| Duration of the storage licence | up to 25 years, extendable for an equal period | same article, (3) |
| Pumped storage | a separate 35-year rule | same article, (3) |
| Co-located storage | a different regime depending on whether the station can charge from the grid | Law 4685/2020, art. 10(11A) and (11B) |
| Adding storage to existing and new PV plants | revised in December 2025 | Law 5261/2025, art. 56, amending art. 11Γ of Law 4685/2020 |
| Decision bringing a project under Standard Environmental Commitments (ΠΠΔ) | within 20 working days of a proper submission | ΥΠΕΝ/ΔΙΠΑ/103448/7298/2024, art. 3(4) |
| Return of an incomplete file | within 10 working days, otherwise the submission is deemed proper | same decision, art. 3(4) |
| Validity of the ΠΠΔ inclusion | no expiry date, as long as the declared data do not change | same decision, art. 5(1) |
| Connection activation request, for stations selected in the first, second and third support procedures | by 15 December 2026 at the latest, otherwise the letter of guarantee is forfeited in full | Law 5233/2025, art. 43(1), as amended by Law 5338/2026, art. 47 |
Stations with an injection capacity below one megawatt are exempt from the storage licence. Exactly 1 MW is not below 1 MW. If you are designing at the threshold, know which side of it you are on before you fix the configuration.
Note, though, that the exemption covers only the storage licence. It does not exempt you from environmental approvals, building approvals or the connection procedure.
The whole route hangs on this distinction. For co-located storage, size is not what counts. What counts is whether the station can charge from the grid. Paragraphs 11A and 11B of article 10 of Law 4685/2020, as amended by articles 79 to 81 of Law 4951/2022, treat the two cases differently.
So do not call every co-located system standalone storage. The charging configuration decides how the Producer Certificate, the environmental act and the connection act are amended.
The storage licence, the environmental authority and the grid operator are three separate competences. None of them prejudges the others.
First document whether the station can charge from the grid, then apply paragraph 11A or 11B, and only then check the current addition route under articles 11Γ and 11Δ. Do not expect the battery to leave the existing approvals untouched. The production act, the environmental act and the connection act are usually amended.
Law 5261/2025 (ΦΕΚ Α΄ 231/12.12.2025) revised the addition regime, and Laws 5299/2026 and 5325/2026 amended it again. The old cut-off dates of 31 October 2024 and 30 April 2025 were removed, and the permanent cap for paragraph 11A stations is now 40% of installed power from 07:00 to 19:00. The rules, the letter of guarantee and the order of examination are in the guide to adding battery storage to solar PV.
Battery projects already classified in category B have their own Standard Environmental Commitments decision: ΥΠΕΝ/ΔΙΠΑ/103448/7298/2024 (ΦΕΚ Β΄ 5628/10.10.2024). Note exactly what it does. It sets the commitments for projects already classified in B under the classification decision in force under article 1 of Law 4014/2011 (art. 1(1)). The classification thresholds come from that other decision, not this one. Its twenty-four pages do not mention a single MW threshold.
The competent body is not the Decentralised Administration. It is the environmental service of the relevant Region (art. 2). That is where the inclusion declaration in Annex A is filed, with the supporting documents listed in art. 4.
There are two clocks, and they work the other way round from what you might expect. The inclusion decision is issued within twenty working days of a proper submission. If the file is incomplete, however, the service must return it within ten working days. If it does not, the declaration is deemed properly submitted (art. 3(4)). Here, silence works in your favour. That is rare in Greek permitting, and worth keeping on record.
The inclusion has no expiry date. It stays in force as long as the data in the declaration do not change (art. 5(1)). Before any change, though, the project goes back to the service, which decides whether a fresh inclusion is needed.
How many inclusion decisions have been issued so far, by month and Region, is on the page environmental approvals for battery storage in numbers.
Two more points change the route. If the station is sited inside a Natura 2000 area, an appropriate assessment of the effects is required (art. 3(5)). And if the battery goes inside the plot of a class B renewable project that is already under Standard Environmental Commitments, with the same developer, the commitments of Annex B apply automatically. The filing is then limited to a brief technical report and a solemn declaration (art. 3(2)(a)).
This is the most common confusion in the market.
Competitive support procedures grant support, not a licence. The framework includes art. 143ΣΤ of Law 4001/2011 and ministerial decision ΥΠΕΝ/ΔΗΕ/55948/1087/20.05.2023 (ΦΕΚ Β΄ 3416). The third procedure was re-announced on 13 December 2024 for 200 MW in Western Macedonia and specific municipalities of the Peloponnese, with a deadline of 23 December 2024. It is mentioned as history: it is not an open procedure today.
For stations already selected, the date that matters now is 15 December 2026. Article 47 of Law 5338/2026 (ΦΕΚ Α΄ 159/05.10.2026) amended art. 43(1) of Law 5233/2025. The letter of guarantee for proper and timely performance of stations selected in the first, second or third ΡΑΑΕΥ competitive procedure (Α΄, Β΄ or Γ΄) is forfeited in full if the request to the transmission system operator to activate the connection (Law 4951/2022, art. 27(2)) is not submitted at all, or is submitted after that date. The separate deadline of 30 September 2026 that applied to third-procedure stations was deleted. For the first and second procedures an earlier condition also applied: the guarantee was forfeited in full if no activation request or complete readiness declaration had reached the competent operator by 30 June 2026. The change applies from 29 September 2026 (art. 50(3)), one day before that deadline would have run out.
The merchant route runs separately. Ministerial decision ΥΠΕΝ/ΓΔΕ/28255/1143/13.3.2025 (ΦΕΚ Β΄ 1248/13.03.2025), with its amendments (ΦΕΚ Β΄ 2886/10.06.2025 and Β΄ 5165/29.09.2025), sets a selection and submission framework for Final Connection Offers to standalone stations without support. Applications were due by 31 October 2025, and a ranking decision by the Minister sets the order of the stations. The caps, groups and criteria are in the merchant battery storage guide.
Law 5299/2026 set maximum durations for administrative licensing. The heading of the relevant provision mentions storage too, but its general paragraph speaks of renewables and high-efficiency combined heat and power (ΣΗΘΥΑ). A blanket two-year limit for standalone storage stations needs confirmation, and we do not present it as certain. The law's other deadlines are in the guide to Law 5299/2026.
MitOS, by Ariadne Labs, keeps a separate route for standalone and for co-located storage, and a separate clock for the storage licence, the environmental act and the connection. The charging configuration is a field of the project, not a note in a document. When the project changes, the route changes with it.
A short demo on the real stages of your projects, with Greek legislation already built in.
For a standalone station, yes, unless its injection capacity is below 1 MW (Law 4001/2011, art. 132E(1) and (2)). At exactly 1 MW the exemption does not apply.
Up to 25 years, extendable for an equal period. Pumped storage has a separate 35-year rule (art. 132E(3)).
What matters is whether the station can charge from the grid. That decides which paragraph applies (11A or 11B of art. 10 of Law 4685/2020) and which acts are amended.
The third procedure closed on 23 December 2024 and is mentioned here as history. Whether any procedure is running today, or whether MW are available on the merchant route, is settled by the grid operator's current announcement.
15 December 2026. By then the request to activate the connection must reach the transmission system operator, otherwise the letter of guarantee for proper and timely performance is forfeited in full. The rule covers the stations selected in the first, second and third procedures (Law 5233/2025, art. 43(1), as amended by Law 5338/2026).
This page summarises provisions for information and is not legal or technical advice for a specific project. The provisions were checked in the original on 2 October 2026, and the Law 5338/2026 amendment on 20 October 2026. Only the official publication in the Government Gazette and the announcements of ΡΑΑΕΥ and the grid operators are authoritative. Environmental classification thresholds for storage stations, the current availability of procedures and transitional provisions are assessed per project.
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