So much solar, so little storage: Greece is struggling to balance PV overproduction – a valuable opportunity for BESS to provide flexibility.
This article explores the Greek power market with a focus on renewable energy and battery storage. Sunny Greece struggles with an overabundance of solar generation, which creates a valuable opportunity for BESS (battery energy storage systems) to provide flexibility and relieve grid pressure.
Greece has emerged as a dynamic renewables market, rapidly scaling solar and wind deployments alongside EU-aligned energy reforms. The country has modernized its electricity market via the Target Model, operates a competitive capacity remuneration mechanism, and is actively rolling out energy storage with dedicated tenders and funding. Greece’s participation in European balancing platforms is advancing, and congestion management and flexibility integration are moving up on the regulatory agenda.
Schematic representation of the European Target Model based on German source image by TenneT
Grid operators and regulatory bodies
Responsible for the high-voltage transmission grid (150 kV and above), system balancing, interconnections, and grid adequacy planning.
Manages the medium and low-voltage distribution network, grid connections for prosumers (entities producing and consuming energy), local metering, and regional RES integration. HEDNO is partially privatized, with a 49% stake held by Macquarie.
Plays a central role in shaping energy market regulations, ensuring compliance with EU directives, and promoting competition and consumer protection. Responsibilities include approving tariffs and grid codes, overseeing market design reforms, licensing market participants, such as BRPs and aggregators, and administering tenders for storage and renewable energy capacity.
RAAEY also represents Greece in pan-European bodies, such as ACER and ENTSO-E, contributing to cross-border market integration and regional balancing coordination. This regulatory influence has been instrumental in enabling Greece’s transition to the EU Target Model and in the rollout of key mechanisms like the capacity remuneration framework and flexibility tenders.
In 2024, Greece achieved big milestones in its energy transition.
Source: The Green Tank
Source: Bloomberg NEF
Greece is quickly emerging as a Southern European leader in battery energy storage, propelled by policy-backed tenders, EU recovery funding, and the pressing need for grid flexibility. As of early 2025, Greece has approximately 100 MW of operational BESS, comprising a small number of FTM (front-of-the-meter) projects and pilots developed prior to the 2023 tenders. Several additional systems became operational in 2024, but the bulk of large-scale storage capacity remains under development.
Following a competitive national tender in 2023, over 900 MW of standalone BESS projects were awarded availability contracts under a € 341 million EU-funded scheme. These projects are scheduled for commissioning between 2024 and 2026, offering 10-year contracts complemented by access to wholesale and balancing market revenues. Greece’s National Energy and Climate Plan (NECP) targets 1.5 GW of storage by 2030, though the total pipeline now exceeds 6 GW of hybrid (BESS co-located with solar or wind) and FTM systems.
Deployment of BTM (behind-the-meter) storage is modest. Due to economic and regulatory limitations, most such installations remain tied to self-consumption PV schemes and are not yet integrated into balancing or grid service markets. The adoption of EU balancing platforms in Greece supports storage market participation with revenue-stacking of energy and capacity.
Greece participates in cross-border trading via SDAC/SIDC and is part of the ENTSO-E Southeast Europe region. The total interconnection capacity currently amounts to approximately 2.5–3 GW, split among:
The Greek power system is increasingly impacted by daily fluctuations caused by high PV penetration (now exceeding 5 GW), which leads to midday oversupply and steep ramping needs during early morning and late evening hours. The lack of adequate hydro storage or baseload nuclear capacity amplifies reliance on gas-fired generation for flexibility. Grid congestion, particularly in southern mainland regions with high solar density, also contributes to curtailment risk and instability during peak injection periods.
Current grid balancing strategy: To manage these imbalances, the system operator (IPTO) primarily relies on RES curtailment, redispatch of thermal units, and flexible gas generation. While effective, this approach can be costly and carbon-intensive. Storage is now increasingly viewed as a key asset in the toolkit, as it offers the ability to absorb excess solar during midday, discharge during demand peaks, and contribute to frequency containment and restoration. The recent BESS tenders are a strategic response to these system needs.
Market Evolution: With Greece’s full integration into PICASSO and MARI, storage assets gain the opportunity to better participate in balancing energy provision after successful prequalification and BRP contracting.
Greece offers multiple revenue streams for energy storage and flexible resources through a combination of energy market participation, balancing services, and availability-based capacity contracts. The wholesale market is operated via HEnEx, where day-ahead and intraday markets are integrated into the SDAC and SIDC platforms, respectively. Storage systems can participate in price arbitrage across 15-minute intervals, although value is increasingly shifting toward flexibility services.
The balancing market, managed by IPTO, settles every 15 minutes. BESS units can participate in aFRR and mFRR markets, subject to prequalification and telemetry compliance. Remuneration for balancing energy follows a pay-as-bid model, while balancing capacity payments (where applicable) are awarded through structured tenders or long-term arrangements.
Under the capacity mechanism, BESS assets awarded contracts via the 2023–2025 tenders receive 10-year availability-based payments through a Contract for Difference (CfD) structure. These are complemented by capital expenditure grants from EU recovery funds. Payments are indexed to availability during designated system stress periods and capped annually. Future revenue stacking is expected to come from layering wholesale, balancing, and possibly congestion relief or ancillary services.
The DAM operates as a daily auction using a pay-as-cleared pricing mechanism. Participants submit hourly block orders by 12:00 CET, with pricing and dispatch results published shortly after. Greece participates in the Single Day-Ahead Coupling (SDAC), allowing cross-border market integration. Harmonized price limits range from -500 EUR/MWh to +4000 EUR/MWh.
Greece holds three scheduled intraday auctions per day at 15:00 (D-1), 22:00 (D-1), and 10:00 (D). These also follow pay-as-cleared pricing and allow hourly, half-hourly, and 15-minute products. The price limits align with the SIDC framework: -9999 EUR/MWh to +9999 EUR/MWh.
This enables continuous trading in 15-minute products up to one hour before delivery. Market participants can revise their positions based on updated forecasts and system needs.
Source: The Green Tank
A key operational distinction in Greece is that energy positions—both in the day-ahead and intraday markets—are scheduled and settled on an asset-specific basis, rather than exclusively within a balancing group. This means that each individual asset, including BESS, is directly registered in the scheduling system and must nominate its intended dispatch independently of its BRP's balancing group net position. As a result, trades executed for a specific asset are automatically scheduled by the market system, simplifying nomination and imbalance risk management for standalone projects.
This structure contrasts with markets like Germany or the Netherlands, where trades must be aggregated at the balancing group level and explicitly nominated to the TSO by the BRP. Greece’s approach enables clearer traceability and faster settlement for asset-level trading. The relevant framework is governed by the Greek Grid Code, specifically Section 5 (Scheduling and Dispatch), and can be referenced via IPTO’s official documentation.
Greece's balancing market is progressively aligning with the European Target Model. BESS participation requires successful prequalification, including demonstration of response times, minimum capacity, and telemetry integration. Balancing energy products are procured by IPTO and divided into three core segments:
Greece participates in the pan-European FCR Cooperation, centrally procuring approximately 50 MW weekly via auction. FCR activates within 30 seconds based on frequency deviations, and BESS units are eligible due to fast response capabilities. Contracts are awarded weekly on a pay-as-cleared basis. Providers must demonstrate symmetrical response capability within 30 seconds, responding automatically to frequency deviations beyond a ±0.01 Hz deadband around 50 Hz. Tests verify rapid ramp rates and sustained capability for at least 15 minutes. Continuous telemetry and accurate frequency measurement are mandatory.
aFRR restores frequency deviations within several minutes. Since 2025, Greece participates in the EU-wide PICASSO platform. IPTO procures around 300 MW daily in six 4-hour blocks. BESS units can participate following prequalification, offering rapid response and telemetry compliance. Remuneration includes pay-as-bid capacity and marginally priced activation payments. Providers must complete a 24-hour baseline test, demonstrating capability to respond promptly to frequency setpoint adjustments from IPTO’s Load Frequency Controller (LFC). Continuous real-time telemetry and maintaining at least 50% of declared capacity during testing are required.
mFRR manages larger, sustained imbalances, typically activating within 15 minutes. Greece procures approximately 600 MW daily, progressively integrating into the EU MARI platform from 2025. Eligible BESS units provide fast response, sustained delivery, and continuous telemetry. Payments combine tender-based capacity remuneration and pay-as-bid activation. Providers must demonstrate the capability to manually activate and deliver declared capacity within 15 minutes, validating ramp rates and prolonged operation through rigorous testing.
| Volume procured | Method | Structure | Common market | |
| FCR | ~50 MW (EU share) | Weekly | Energy only | FCR Cooperation |
| aFRR | ~300 MW | Daily | Energy + capacity | PICASSO since 2025 |
| mFRR | ~600 MW | Daily | Energy + capacity | MARI expected during 2025 |
Greece operates with a 15-minute imbalance settlement period (ISP), aligning with EU standards. Imbalances are calculated by IPTO for each Balance Responsible Party (BRP) by comparing the scheduled energy deliveries from day-ahead and intraday markets with actual metered values. Deviations between these scheduled and actual deliveries represent imbalances. Imbalance prices are determined based on the cost of balancing energy activated by IPTO during each ISP, reflecting the weighted average price of activated balancing services.
Post-gate closure adjustments can occur due to real-time system conditions requiring additional balancing actions, which may affect imbalance prices. This structure incentivizes participants to accurately forecast and schedule their energy to minimize financial exposure to imbalance charges.
Greece has initiated a series of competitive tenders to bolster its energy storage infrastructure, aiming to integrate significant battery energy storage systems (BESS) into its electricity grid. These tenders are part of a broader strategy to enhance grid flexibility and support renewable energy integration.
Tender overview
Contract duration: Each awarded project enters a 10-year CfD, ensuring revenue stability by covering the gap between market revenues and a predefined reference income.
Investment grants
Contractual obligations
In 2025, enspired brought a full-stack solution for battery optimization to the Greek market in a partnership with Optimus Energy, the country’s leading RES aggregator. The collaboration centers around several BESS projects with a total capacity of 270 MW and leverages the urgent need for storage to accommodate the surplus of solar energy. The availability of cross-market optimization is new to Greece and caters to everyone looking to monetize battery flexibility locally.
Learn more about the partnership here.
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