A Greek PV plant with an electricity sale contract or an operating support contract can add a battery and keep its contract for the energy from its PV units. Article 11Γ of Law 4685/2020 sets the terms, as rewritten by Law 5261/2025 and amended by Laws 5299/2026 and 5325/2026. The battery needs at least one hour of capacity. If it charges from the PV only, the plant injects no more than 40% of its installed power from 07:00 to 19:00. Every application comes with a letter of guarantee.
Last updated: · Also in Greek: Προσθήκη μπαταρίας σε υφιστάμενο φωτοβολταϊκό: τι ισχύει σήμερα
| What | Rule | Provision |
|---|---|---|
| Which PV plants | plants commissioned after 4 July 2019, new plants with a Final Connection Offer that were not operating on 1 December 2025, and new plants that will receive one, provided they hold a sale contract or an operating support contract; also self-consumption PV and PV selling in the market without support | art. 11Γ par. 1 and 4, Law 4685/2020 |
| Minimum capacity | usable capacity of at least one hour at the PV plant's installed power | art. 11Γ par. 1 |
| Where the request goes | to the Licensing Body for RES and High-Efficiency CHP or to the competent operator, as the case may be | art. 11Γ par. 1 |
| Payment | the sale or support contract stays in force for the energy from the PV units; energy from the battery is paid at day-ahead and other market prices, measured by a separate certified meter | art. 11Γ par. 2 and 3 |
| Limit when charging from the PV only (par. 11A) | a permanent cap of 40% of installed power from 07:00 to 19:00, no permanent cap from 19:00 to 07:00 | art. 11Γ par. 5.α(a), as amended by Law 5299/2026 |
| Limit when also charging from the grid (par. 11B) | the hourly injection limits for storage stations on the transmission system, until more specific limits are set | art. 11Γ par. 5.α(b); ΥΠΕΝ/ΔΑΠΕΕΚ/53563/1556/2023, art. 4 |
| Permit amendments | the Producer Certificate, the Final Connection Offer, the environmental permits and any other permit are amended with priority | art. 11Γ par. 4 |
| ΔΕΔΔΗΕ: requests after 30 November 2025 that take new grid capacity | examined only after the 900 MW for standalone storage on the distribution network is used up, except the "Storage Systems in Businesses" programme | art. 11Γ par. 4, as amended by Law 5299/2026 |
| Shared connection point | a joint request for a storage station sized up to the PV plants' combined installed power; on the transmission system, absolute priority up to 1,000 MW until the merchant battery ranking decision | art. 11Γ par. 5 and 5.δ, as amended by Law 5325/2026 |
| Letter of guarantee | required for every application; based on maximum generation power (par. 11A) or maximum injection power (par. 11B) | art. 11Γ par. 5.γ, as amended by Law 5299/2026; art. 6, Law 4951/2022 |
| Fire safety | the measures of sections Στ.1 and Στ.2 of Annex Β of ΥΠΕΝ/ΔΙΠΑ/103448/7298/2024 | art. 11Γ par. 7 |
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Article 11Γ first covers PV plants with an electricity sale contract or an operating support contract (sliding feed-in premium or feed-in tariff). Three groups qualify: plants commissioned after 4 July 2019, plants with a Final Connection Offer that were not operating on 1 December 2025, and plants that will receive a Final Connection Offer in future. Where it is technically possible, they convert into stations with integrated storage under paragraph 11A of article 10. The request goes to the Licensing Body for RES and High-Efficiency CHP or to the competent operator, as the case may be (par. 1). Self-consumption PV and PV selling directly in the market without operating support can also apply to add storage (par. 4).
Law 5261/2025 (Government Gazette Α΄ 231/12.12.2025) removed the old cut-off dates: 31 October 2024 for new PV plants and 30 April 2025 for filing the request. Notified stations under article 38 of Law 4951/2022 fall outside article 10 of that law, so the injection limits of paragraph 5.α do not apply to them (added by Law 5299/2026).
The first decision is whether the battery will also charge from the grid. Law 4685/2020 (article 10, paragraphs 11A and 11B, added by Law 4951/2022) defines two types of station with storage installed behind the meter. Article 11Γ treats them differently:
| Topic | Par. 11A: charging from the PV only | Par. 11B: charging also from the grid |
|---|---|---|
| Drawing power from the grid | no, except for the station's auxiliary consumption | yes, for storage |
| Licensing act | Producer Certificate | Special Projects Certificate |
| Injection limit under article 11Γ | 40% of the PV plant's installed power from 07:00 to 19:00 | the hourly limits of Β΄ 3328/2023 for storage stations on the transmission system |
| Power used for the letter of guarantee | maximum generation power | maximum injection power |
| 500 MW cap per group on batteries until 2029 | does not count | counts |
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A paragraph 11A station can later become a paragraph 11B station. It then follows the paragraph 11B limits instead of those in its original Final Connection Offer. If it holds a support or sale contract, article 12A of Law 4414/2016 applies. A paragraph 11B holder must also stay within the 500 MW cap per group on batteries until the end of 2029 (art. 11Γ par. 6A and art. 11Δ par. 8).
When a PV plant converts into a paragraph 11A station, the law sets a permanent cap on its maximum generation power: 40% of the PV plant's installed power from 07:00 to 19:00 on each dispatch day. From 19:00 to 07:00 there is no permanent cap. A 10 MW plant therefore injects no more than 4 MW from 07:00 to 19:00. Law 5261/2025 had set the figure at 60%. Law 5299/2026 (Government Gazette Α΄ 67/05.05.2026) cut it to 40%.
A paragraph 11B station instead follows the limits that article 4 of ΥΠΕΝ/ΔΑΠΕΕΚ/53563/1556/2023 (Government Gazette Β΄ 3328) sets for storage stations on the transmission system. These apply until more specific limits are set by the decision under article 10(5) of Law 4951/2022 for storage and paragraph 11B stations on the distribution network (par. 5.α(b)). The decision sets the maximum permitted injection as a share of the maximum injection power in the licence:
| Hours of the dispatch day | Maximum permitted injection |
|---|---|
| 09:00 to 10:00 | 70% |
| 10:00 to 11:00 | 35% |
| 11:00 to 15:00 | 0% |
| 15:00 to 16:00 | 35% |
| 16:00 to 17:00 | 70% |
The operator applies corresponding limits to new applications for a Final Connection Offer for paragraph 11A and 11B stations.
The operating support contract or sale contract stays in force and covers the energy injected by the PV units (par. 3). Energy that comes from the battery is paid by the market instead: at the hourly day-ahead price and the prices of the other markets the station takes part in. A separate certified meter at the battery output measures it (par. 2).
A request to add storage amends, with priority, the Producer Certificate, the Final Connection Offer (subject to article 5(19)(ζ) of Law 4951/2022), the environmental permits and any other permit or approval (par. 4). The operator examines the amended Final Connection Offers in parallel with the projects in Tables 2A and 2B of ΥΠΕΝ/ΔΑΠΕΕΚ/88889/2592/2024 (Government Gazette Β΄ 4918) and the storage stations selected in ΡΑΑΕΥ's tenders.
On ΔΕΔΔΗΕ's distribution network there is an important exception. Requests that take new grid capacity and were filed after 30 November 2025 go into Priority Group Β of ΥΠΕΝ/ΔΑΠΕΕΚ/28857/1083/2020 (Government Gazette Β΄ 940). They are examined only after the 900 MW of Final Connection Offers for standalone storage in groups ΕΔΔΗΕ Α΄ to Δ΄ of the merchant battery call has been granted and used up. Approved applications under the "Storage Systems in Businesses" programme (Government Gazette Β΄ 6978/2024) are exempt. Law 5261/2025 drew the line at connection through an independent inverter. Since Law 5299/2026, the test is whether the request takes new grid capacity.
New PV applications filed with ΔΕΔΔΗΕ under the second sentence of article 97(8) of Law 4951/2022 must include a battery with at least one hour of usable capacity. The plants are installed as paragraph 11A or 11B stations. The deadline for ΔΕΔΔΗΕ to start accepting these applications moved to 1 April 2026 (par. 5.β).
Law 5299/2026 extended the rule to PV applications kept pending for up to five years under article 10(5) of ΥΠΕΝ/ΓΔΕ/84014/7123/2022 (Government Gazette Β΄ 4333). For these, the holder files a request to add a battery whose maximum injection power does not exceed the installed power of the original application. A complete request keeps the original completeness date. ΔΕΔΔΗΕ examines the two as one application for a paragraph 11A or 11B station, with the limits of paragraph 5.α.
Where several PV plants connect at a common point on the distribution network or the transmission system, their holders can file a joint request for one storage station at that point. The station's maximum absorption and maximum injection power cannot exceed the PV plants' combined installed power. Its usable capacity must be at least one hour at that combined power. One PV holder alone, or a storage licence holder, can also file the request, with an agreement with the other side. The operator assesses it with absolute priority (par. 5, as replaced by Law 5325/2026, Government Gazette Α΄ 122/31.07.2026).
The PV plants may then inject beyond their static or dynamic limits and beyond the dispatch schedule, provided the battery absorbs the same energy at the same time. They are not paid for that energy, by the market or by support. Combined injection from the PV and the battery cannot exceed the PV plants' combined maximum injection power after the permanent limits of article 10 of Law 4951/2022. The battery cannot start operating before the PV plants. Its holder must also amend, split or replace the storage licence once before the Connection Agreement.
On the transmission system, ΑΔΜΗΕ examines these requests with absolute priority up to 1,000 MW of Final Connection Offers, until the ministerial ranking decision for the merchant battery call is issued (art. 11Δ par. 7). After that decision and the first 1,000 MW, it alternates blocks of 1,000 MW between standalone stations selected in the call and joint requests filed by 31 July 2026, until the call's 3,800 MW cap is reached. If this order leaves a selected station without an offer, that station can receive one through an extension of the substation, a new substation or a connection to another one, where technically possible. Joint requests filed after 31 July 2026 rank as storage stations under the priority framework of Β΄ 4333/2022 (par. 5.δ).
Each joint request ranks by the date on which all the required documents were filed. If PV plants are added later and the battery's power rises, or a new battery is added, the request takes a new place based on the date of the amendment. A power increase after the Final Connection Offer ranks as a new request (par. 5.ε). Storage stations that receive a Final Connection Offer under the fourth sentence of paragraph 5.δ file their readiness declaration within 30 months of accepting it (art. 25A par. 7, Law 4685/2020).
Since 12 December 2025, every application to the operator, whether to add a battery to an existing PV plant or for a new PV plant with a battery, comes with a letter of guarantee under article 6 of Law 4951/2022. This applies however the battery connects to ΔΕΔΔΗΕ's network. The amount is based on maximum generation power for a paragraph 11A station and on maximum injection power for a paragraph 11B station. For additions to existing PV plants, article 89A of Law 4951/2022 on returning and reducing guarantees does not apply (par. 5.γ, as amended by Law 5299/2026). The amounts per MW are in the guide to letters of guarantee.
Adding a battery triggers the fire-fighting measures of sections Στ.1 and Στ.2 of Annex Β of ΥΠΕΝ/ΔΙΠΑ/103448/7298/2024 (Government Gazette Β΄ 5628). That is the same decision that sets the Standard Environmental Commitments for standalone batteries (par. 7). The environmental route for batteries is in the battery storage permitting guide.
Paragraph 6 lets the Minister set, by decision, the total PV power that may add storage, its split between ΔΕΔΔΗΕ and ΑΔΜΗΕ, a deadline for applications, connection and market details for joint requests, a suspension of new paragraph 5 offers, and sanctions. As of 20 October 2026 we had not found such a decision published. Joint requests that receive a Final Connection Offer before it will be bound by its terms once it is issued. ΑΔΜΗΕ's alternating order also waits on the ranking decision for the merchant battery call, which we had not found published either.
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.
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Yes, if the plant was commissioned after 4 July 2019 or is new with a Final Connection Offer, and the addition is technically possible. The sliding feed-in premium or feed-in tariff contract stays in force for the energy from the PV units. Energy from the battery is paid at market prices (art. 11Γ par. 1 to 3, Law 4685/2020).
Usable capacity must be at least one hour at the PV plant's installed power: at least 5 MWh for a 5 MW plant (art. 11Γ par. 1).
Only if the plant becomes a paragraph 11B station under article 10 of Law 4685/2020, with a Special Projects Certificate. The hourly injection limits for storage on the transmission system then apply, and its power counts towards the 500 MW cap per group on batteries until 2029.
No. Law 5299/2026 (Government Gazette Α΄ 67/05.05.2026) cut the permanent cap for paragraph 11A stations to 40% of the PV plant's installed power, from 07:00 to 19:00.
Yes, for every application to the operator since 12 December 2025, under article 6 of Law 4951/2022. It is based on maximum generation power (par. 11A) or maximum injection power (par. 11B). For an addition to an existing PV plant it is not returned or reduced under article 89A.
This page summarises provisions for information and does not replace legal or technical advice on a specific project. The provisions were checked in the original Government Gazette on 20 October 2026. Only the official publication in the Gazette and the announcements of ΥΠΕΝ, ΡΑΑΕΥ and the operators are authoritative.
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