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The role of BESS in the Greek power market

Written by enspired | Jun 17, 2025 2:30:00 PM

BESS in Greece

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.

 

Market overview

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

  • TSO: IPTO/ ADMIE (Independent Power Transmission Operator)

Responsible for the high-voltage transmission grid (150 kV and above), system balancing, interconnections, and grid adequacy planning.

  • DSO: HEDNO/ ΔΕΔΔΗΕ (Hellenic Electricity Distribution Network Operator)

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.

  • National regulator: RAAEY (Regulatory Authority for Energy, Waste & Water)

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.

 

The energy mix in Greece

In 2024, Greece achieved big milestones in its energy transition.

  • Renewables: Renewable energy sources (RES), including wind, solar, and hydro, accounted for approximately 57% of the electricity output – a substantial increase driven by investments in solar and wind energy projects.
  • Lignite: Lignite-fired power generation declined to a record low with a contribution of around 3,236 GWh in 2024.
  • Natural gas and oil: The remaining electricity generation was covered by natural gas and oil-fired plants, with the former playing a considerable role in grid balancing.
  • Net exports: A rare occurrence in the country’s energy history, Greece became a net exporter of electricity in 2024, with net exports amounting to 307 GWh.
  • Electricity demand: In 2024, Greece’s electricity consumption reached approximately 56.9 TWh, marking a 5.5% increase compared to 2023. This rise follows two consecutive years of decline and is attributed to factors such as economic recovery, increased electrification, and a surge in tourism.

Source: The Green Tank

 

Source: Bloomberg NEF

 

Outlook for BESS in Greece

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.

  • PICASSO: active for aFRR since early 2025
  • MARI: full integration anticipated in 2025 for mFRR

 

Interconnections

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:

  • Italy (400 kV DC cable): ~500 MW
  • Bulgaria (400 kV): ~1,200 MW
  • North Macedonia (400 kV): ~400 MW
  • Albania (400 kV): ~200–300 MW
  • Turkey (400 kV): ~400 MW (limited commercial exchange)

 

Grid connection and system balancing

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.

 

BESS revenue streams in Greece

  • Ancillary services
  • Wholesale markets
  • Imbalance markets

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 Greek wholesale market

  • Day-ahead market

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.

  • Intraday auctions (IDAs)

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.

  • Continuous intraday market (SIDC)

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

 

Matching and scheduling

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

 

Ancillary services Greece

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:

  • Primary reserve: FCR (Frequency Containment Reserve)

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.

  • Secondary reserve: aFRR (automatic Frequency Restoration Reserve)

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.

  • Tertiary emergency reserve: mFRR (manual Frequency Restoration Reserve)

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

 

Imbalance market and pricing system

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.

 

Capacity market tenders and contracts

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

  • 1st tender (Q3 2023): 400 MW awarded
  • 2nd tender (Q4 2023): approximately 288 MW awarded
  • 3rd tender (Q1 2024): approximately 189 MW awarded

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

  • 1st tender: €200,000 per MW
  • 2nd tender: €100,000 per MW
  • Operating aid: Capped at €115,000 per MW per year for the first two tenders, with the third tender allowing bids up to €145,000 per MW per year.

Contractual obligations

  • Commission deadlines: Achieve commercial operation by specified dates (e.g., by the end of 2025 for the first two tenders).
  • Performance guarantees: Submit letters of guarantee, including participation guarantee (€35,000 per MW), good performance guarantee (€150,000 per MW), and good operation guarantee (€150,000 per MW).
  • Market participation: Engage in electricity markets, provide balancing services, and adhere to grid codes.
  • Reporting: Submit quarterly progress reports and annual confirmations of compliance with capacity limits.

 

Cross-market battery optimization now available in Greece

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.

 

Are you interested in maximizing revenues for your BESS in Greece?

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Sources:

Ekathimerini

The Green Tank

Strategic Energy Europe

IPTO

Bloomberg NEF

Spyropoulos

TenneT