BESS projects in Greece: New Ministerial Decision boosts integration of large-scale energy storage

On 13 March 2025, the Greek government issued Ministerial Decision ΥΠΕΝ/ΓΔΕ/28255/1143 (Government Gazette 1248/B/13.03.2025) on the priority regime for the final grid connection of standalone BESS projects.

The decision describes the conditions a BESS owner has to meet to submit a “priority” request for a final connection to the grid. It sets out eligibility criteria, priority rules, capacity caps, ownership concentration limits and financial assurance requirements. 

In this article, we provide a summary of the key points of the Ministerial Decision.

Classification and capacity caps for eligible BESS projects

The decision classifies eligible projects into priority groups. Each group is subject to capacity caps depending on whether the BESS project will be connected to the Transmission Network (ESMIE) or the Distribution Network (EDDIE).

The priority groups and their respective capacity limits are based on factors such as the conclusion of bilateral binding agreements, geographical location and eligibility for BESS projects owned by grid aggregators (Fose).

 

Priority group	Maximum capacity (MW)	BESS project
ESMIE A1	500	For BESS projects that have signed binding bilateral agreements with energy-intensive industries for a minimum of eight years.
ESMIE A2	100	For BESS projects that have signed binding bilateral agreements with enterprises for a minimum of eight years.
ESMIE A3	300	For BESS projects owned by Grid Aggregators (Fose).
ESMIE B	250	For BESS projects in lignite phase-out zones.
ESMIE C	2,550	Distributed across various regions for projects that don’t fall under the priority groups ESMIE A1, ESMIE A2, ESMIE A3 and ESMIE B.
EDDIE A	350	For BESS projects > 5 MW
EDDIE B	150	For BESS projects 1-5 MW
EDDIE C	150	For BESS projects < 1 MW
EDDIE D	250	For BESS projects that have signed binding bilateral agreements with enterprises for no less than eight years.

 

Financial solidity requirements

To be eligible for the priority regime, investors have to demonstrate financial solidity by submitting:

• a priority bond; and
• a pre-approved or fully approved bank loan for project financing and/or proof of available funds. The amount of the pre-approved or approved bank loan and/or own available funds would need to cover the total CAPEX of the BESS project (reference project cost of EUR200/kWh).

Technical and licensing requirements

BESS projects eligible for the priority regime also have to meet specific technical and licencing requirements. They have to:

• hold a valid storage permit issued by Greek Regulatory Authority for Energy, Waste and Water (RAAEY);
• have submitted a final grid connection offer application;
• hold an environmental permit;
• have a capacity power of at least 0.5 MW and a two-hour discharge capacity;
• have secured land rights;
• have not participated or intend to participate in auctions for investment or operating aid; and
• have not received a final grid connection offer relating to the integration of the BESS into existing or new Renewable Energy Storage (RES) projects.

Key deadlines for application submission

For BESS projects connected to ESMIE, the deadline is 90 days from the publication date of the Ministerial Decision. There’s an extended deadline of 150 days for Crete, the Ionian Islands, and the Cyclades.

For BESS projects connected to EDDIE, the deadline is 150 days from the publication date of the decision.

Anti-concentration criteria

To avoid market concentration, Article 5 of the Ministerial Decision establishes cumulative ownership limits:

• There’s a maximum capacity of 250 MW for each natural or legal person, including their related parties.
• Each natural or legal person and its related parties are permitted a maximum total capacity of 500 MW until 2029 for standalone BESS or BESS combined with RES projects, except for self-generation storage units.

Transferring a BESS project at any stage of its development and operation is prohibited if the transfer violates the anti-concentration criteria outlined in par. 1 to 5 of Article 5. RAAEY and the competent operators will carry out the relevant controls.

Timeline for implementing BESS projects

BESS projects for which final grid connection will be granted have to submit a statement of readiness within 18 months of the Final Offer of Connection being accepted. Upon receiving the Final Grid Connection Offer, the priority bond will be replaced by a performance and operation bond for EUR200,000/MW for BESS projects connected to ESMIE and EUR50,000/MW for BESS projects connected to EDDIE. After three years of BESS operation, the performance and operation bond amount will be reduced by 50%. It will be fully refunded after six years of BESS operation.

Penalties

The application bond or performance bond will be forfeited if a project doesn’t meet the requirements outlined in the Ministerial Decision, including anti-concentration requirements, submitting false information or timely electrification. The grid operator will also suspend the project's grid connection until complete compliance is ensured. The grid connection will be restored once the project fully complies with the requirements.

Conclusion

As Greece continues to accelerate its energy transition, the new BESS regulatory framework is a crucial step forward in the country's efforts to modernise and decarbonise its energy sector. This initiative can play a key role in enabling the large-scale integration of energy storage systems into the national grid, which is essential for ensuring a more resilient and sustainable energy future.