ACER published its report on the implementation of the inter-transmission system operators compensation mechanism (ITC) for 2024. 

ACER issues these yearly monitoring reports since 2012, as mandated by the Commission’s Regulation. 

What is the ITC mechanism?

The inter-transmission system operators compensation (ITC) mechanism, managed by the European Network of Transmission System Operators for Electricity (ENTSO-E), compensates transmission system operators (TSOs) for the costs of hosting cross-border flows on their networks (including costs from power losses and infrastructure investments).

The mechanism works through the ITC fund: participating TSOs both contribute and receive money from it, depending on how much electricity they import, export and transmit across their national borders. The aim of the mechanism is to ensure that costs and benefits are fairly shared among the TSOs.

The ITC mechanism currently includes 36 TSOs from across the EU and neighbouring countries, including the Ukrainian TSO Ukrenergo, who officially joined the ITC agreement in July 2024.

What are the key findings for 2024? 

• After increasing significantly in 2022 and 2023, the ITC fund fell from €1.14 billion in 2023 to €879.9 million in 2024, mostly due to a decrease in electricity wholesale prices (although these remain well above pre-crisis levels).
• As a result of lower wholesale prices, most TSOs (28 out of 36) saw lower loss costs compared to 2023. On average, weighted loss costs fell 28% to 145.97 €/MWh.
• As in previous years, the cost of losses varied widely among EU ITC parties, ranging from 63 to 259 €/MWh. Actual electricity losses also differed significantly across countries.
• ACER finds that the ITC mechanism in 2024 generally complies with EU legal requirements. However, it recommends further methodological improvements, in line with its Recommendation on the treatment of losses (2023), including calculating loss volumes in more detail and using actual loss costs.

What are the next steps?

ACER is currently reviewing existing EU mechanisms for sharing the costs and benefits of electricity network infrastructure arising from cross-border trade, including the ITC mechanism. The aim is to better reflect the EU-wide benefits of the grid and to facilitate infrastructure investments that extend beyond national interests and needs. The findings of this exercise will feed into an ACER policy paper in 2026.

Access all ACER ITC monitoring reports.

On 17 December 2025, the European Network of Transmission System Operators for Electricity (ENTSO-E) submitted its proposal for the European Resource Adequacy Assessment (ERAA) 2025 to ACER.

What is ERAA?

Mandated by the 2019 Clean Energy Package, the ERAA is ENTSO-E’s annual evaluation of the risks to the EU’s security of electricity supply for up to 10 years ahead. Following the methodology approved by ACER in 2020, ENTSO-E must carry out an annual assessment on whether the EU has sufficient electricity resources to meet future demand.

At national level, Member States set their own electricity reliability standards to indicate the level of security of electricity supply they need. At European level, the ERAA verifies whether the EU’s electricity system can meet these national standards. 

How does the ERAA benefit the EU?

The ERAA provides an objective basis for identifying potential risks to Europe’s security of electricity supply and for determining whether additional national measures, such as capacity mechanisms, are needed. It helps inform decisions by Member States and the European Commission (e.g. state aid decisions) on national security of electricity supply measures.

What are the next steps?

Every year, where necessary, ACER suggests how to improve the next ERAA before ENTSO-E begins its work (e.g. see ACER suggestions for the ERAA 2025). ACER also actively engages with ENTSO-E throughout the year.

ACER will review and decide on ENTSO-E’s proposed ERAA 2025 within three months of its submission. 

Read more on ERAA.

On 2 July 2025, ACER received a proposal from the EU transmission system operators (TSOs) to amend the methodology for intraday cross-zonal gate opening and closure time. 

What is the methodology about?

Established under the Capacity Allocation and Congestion Management (CACM) Regulation, the methodology sets harmonised rules across EU Member States for when electricity trading can begin (gate opening time) and end (gate closure time) in the intraday market. The intraday market is a short-term market where electricity is bought and sold on the same day as delivery after the day-ahead market has closed. 

The TSOs proposed shortening the gate closure time from the current 60 to 30 minutes before delivery, while keeping the gate opening time unchanged. 

Shortening the gate closure time is expected to:

• allow market participants to trade closer to real time, giving them more time to respond to last-minute changes in demand and supply;
• support the integration of renewable energy sources and flexibility solutions; and
• help TSOs keep the system balanced and the supply secure.

This amendment aims to align the methodology with the requirements of the Electricity Market Design Reform (2024), which seeks to improve the efficiency of short-term markets.

What did ACER decide? 

On 19 December 2025, ACER approved the TSOs proposal, adding several clarifications and adjustments, including:

• Derogations and the 30-minute gate closure time: If a TSO receives a derogation, the 30-minute gate closure time cannot be applied on that bidding-zone border until the derogation ends. The TSO on the opposite side of the border does not need its own derogation; it simply continues applying the 60-minute gate closure time. Once all derogations on that border expire, all involved TSOs must switch to the 30-minute standard without delay.
• Borders with Energy Community Contracting Parties: As the Electricity Market Design Reform has not yet been fully adopted by the Energy Community Ministerial Council, it is not part of national laws in thee Energy Community countries. Until adoption, applying the 30-minute gate closure time on these borders is optional, while the 60-minute remains the mandatory standard.

What are the next steps? 

From 1 January 2026, the first TSOs will start implementing the 30-minutes gate closure time, with full rollout subject to national regulatory decisions.

On 18 December 2025, ACER received two proposals from the European electricity transmission system operators (TSOs) to amend the implementation frameworks for two European platforms for exchanging balancing energy.  

These frameworks describe the design of the Platform for the International Coordination of Automated Frequency Restoration and Stable System Operation (PICASSO) and Manually Activated Reserves Initiative (MARI). These European platforms help integrate European balancing energy markets by using a common merit order list to enable cost-efficient activation of balancing energy bids across Europe.

What are the proposals about?

The TSOs’ proposals amend how balancing service providers (BSPs) participate in the European balancing markets. These markets operate in near real time, with BSPs offering services that TSOs purchase to correct imbalances (e.g. by increasing electricity generation or reducing consumption) and keep the electricity system secure.

The main focus of the TSOs’ proposals is the harmonisation of the BSPs prequalification process, which ensures that power generation or demand units meet the technical and operational requirements to provide balancing services. The proposals also harmonise the procedure for amending the implementation frameworks for the balancing platforms across Europe. 

Why amend the implementation frameworks?

As cross-border exchanges of balancing products grow, ensuring a level playing field for BSPs becomes increasingly important. Harmonising prequalification rules across Member States is key to ensuring fair, transparent and efficient access to European balancing markets.

What are the next steps?

ACER will review the TSOs’ proposals to ensure they align with the Electricity Balancing Regulation and the Regulation on the Internal Market for Electricity. 

To inform its decision, ACER will run a public consultation from 26 January 2026 to 23 February 2026.

ACER will decide whether to amend the implementation frameworks by 18 June 2026.

In July 2025, electricity transmission system operators (TSOs) submitted to ACER their proposal to amend how capacity calculation regions (CCRs) are defined across Europe.

With its Decision 10-2025, ACER has approved the proposed amendments.

What are capacity calculation regions and why are they important? 

CCRs are geographic areas across Europe that group neighbouring electricity bidding zones and their borders. Within each region, TSOs work together to determine how much electricity can safely flow across borders while ensuring security of supply.

There are currently nine CCRs in the EU: Nordic, Hansa, Core, Italy North, Central Europe (CE), Greece-Italy (GRIT), South-West Europe (SWE), Baltic and South-East Europe (SEE).

Well-defined CCRs benefit European consumers and producers by: 

• helping TSOs coordinate regional processes such as capacity calculation, redispatch and countertrading more effectively; and
• optimising cross-zonal capacity, facilitating electricity trade across borders and ensuring security of supply.

What did ACER decide?

ACER assessed whether the TSOs’ proposal supports market integration, non-discrimination, effective competition and the well-functioning of the EU electricity market.

Following a public consultation in summer 2025, ACER has approved the TSOs’ proposal to:

• Merge two existing CCRs (Core and Italy North) into the Central Europe CCR across multiple timeframes and methodologies. The Central Europe CCR, previously limited to the day-ahead timeframe, will now also cover:
  • intraday capacity calculation;
  • regional operational security coordination (ROSC); and
  • coordinated redispatching and countertrading (RDCT), along with their cost-sharing methodology (RDCT CS).

• Expand the existing South-East Europe CCR and establish three new CCRs (East-Central Europe*, Italy-Montenegro and Eastern Europe) to include the bidding zone borders and TSOs of the Energy Community Contracting Parties and neighbouring EU countries.

  *The ECE region is established as a temporary setup, with the intention to merge it with the Central Europe CCR in the future.

  These changes are necessary to reflect the growing integration of Energy Community countries into the EU electricity market and strengthen cooperation and efficiency across borders.

Next steps

Once the conditions for integrating the East-Central Europe CCR into the Central Europe CCR are met, TSOs shall submit to ACER a new proposal to formally merge the two regions. 

Today, ACER releases its Opinion on France’s National Resource Adequacy Assessment (NRAA). This assessment complements the European Resource Adequacy Assessment (ERAA) 2024, using input assumptions and modelling approaches that better reflect the characteristics of the national electricity system, drawing on historical data and recent developments.

What is a resource adequacy assessment?

The European Resource Adequacy Assessment (ERAA) evaluates electricity resource adequacy across the EU and provides a consistent framework to assess whether additional national measures are needed to ensure security of supply. ERAA is carried out annually by the European Network of Transmission System Operators for Electricity (ENTSO-E) and reviewed by ACER.

Member States can complement the European analysis through national assessments (NRAAs). While based on the ERAA methodology, NRAAs may capture new developments or national specificities not yet reflected in the latest ERAA.

When a national assessment identifies new adequacy concerns, the Member State informs ACER. In turn, ACER issues an opinion on the differences between the national and European assessments.

What did ACER find?

ACER finds the French assessment clear, robust and generally aligned with ERAA 2024 for most target years. However, unlike ERAA, the NRAA identifies an adequacy concern for 2030, estimating nearly twenty hours during the year when electricity demand would not be met (above France’s reliability standard of two hours). 

ACER notes that most differences with ERAA 2024 are justified by national specificities or methodological improvements. In particular, the NRAA introduces several good practices, including: 

• Considering revenues from ancillary services (e.g. balancing and grid-stability services), which better shows how flexible resources (such as batteries) can earn revenue.
• Ensuring consistency between investment and adequacy modules, strengthening the overall coherence and robustness of the assessment.
• Better accounting for available capacity from neighbouring countries by adjusting it to match national reliability standards, resulting in a more balanced estimate of how much France can rely on cross-border electricity.

The map displays the capacity mechanisms in place across Europe in 2025 and their expiration date. It shows how France’s neighbouring countries have running capacity mechanisms in place. Their impact should be taken into account to ensure an accurate assessment of risks in France. Source: ACER’s Monitoring Report on security of EU electricity supply, p.12.

At the same time, ACER identifies three unjustified differences that could overestimate the projected risks.

1. Conservative estimation of market revenues for adequacy resources (impacting investment prospects).
2. Not considering that the legally set maximum price may change in the future.
3. Using a simplified cross-border capacity calculation that does not reflect the actual operations of the grids. 

What are the next steps?

ACER encourages the French authorities to consider its recommendations to ensure a more accurate assessment of adequacy risks.

See other ACER’s opinions on national assessments.

In September 2025, ACER received a proposal from the European Network of Transmission System Operators for Electricity (ENTSO-E) to amend the methodology for the regional procurement of balancing capacity. After reviewing the proposal and exchanging with stakeholders, ACER has decided to amend the methodology.

What’s new in the amended methodology?

The methodology for the regional procurement of balancing capacity (first approved by ACER in 2023) enables regional coordination centres (RCCs) to assess how voluntary balancing bids can be utilised effectively across borders. Following this evaluation, RCCs provide transmission system operators (TSOs) with recommendations to reduce the volume of procured balancing capacity, hence utilising the flexibility of the EU electricity system and lowering costs. 

The amended methodology:

• Updates the reliability parameters used by RCCs to assess the availability of voluntary balancing bids and cross-zonal capacity. This change will foster a more transparent and coordinated process and improve the balancing of the EU power system.
• Allows RCCs and TSOs to decide on the geographical area where their assessment on the use of voluntary balancing bids will be performed. This will better align the process with the local context and allow for a more effective and coherent practice across Europe. 

What are the next steps? 

RCCs are tasked to assess and provide recommendations on how the use of voluntary balancing bids can be optimised by 19 January 2026.

Interested in learning more about the role of RCCs? Access the latest report on the monitoring of regional coordination centres, published today.

Today, ACER publishes its third monitoring report on the reporting obligations of Regional Coordination Centres (RCCs) for 2024, and its new RCC monitoring dashboard.

Regional Coordination Centres (RCC) were introduced in 2022 with the Electricity Regulation to facilitate coordination among electricity transmission system operators (TSOs) across regions. They contribute to grid stability, security of supply, and the EU’s energy and climate goals. RCCs are required to report on the outcome of their activities, including:

• operational performance;
• coordinated actions;
• issued recommendations; and
• designated tasks.

What is in the ACER monitoring report?  

This report covers RCC’s self-reporting efforts in 2024 and, for the first time, more detailed information on 4 tasks requested by ACER: 

• week-ahead to at least day-ahead adequacy assessments;
• outage planning coordination;
• seasonal adequacy assessments;
• training and certification of RCC staff.

With this dashboard, stakeholders are able to assess implementation progress of RCCs’ tasks and compare the RCCs in Europe. The monitoring will be expanded over time to cover all 16 RCC tasks.

What did ACER monitoring find?  

RCCs continued advancing their activities in 2024. Currently, 7 tasks are in operation across all RCCs:

• common grid model;
• short-term adequacy;
• outage planning coordination;
• defence and restoration plan consistency;
• training and certification;
• post-disturbance analysis; and
• crisis scenarios.

This compared with 4 tasks in operation for 2023 and none in 2022. ACER welcomes this progress.

However, ACER finds that: 

• key performance indicators (KPIs) remain difficult to compare across RCCs due to regional differences in the KPI design, and data quality issues;
• Supporting restoration, the optimisation of inter-TSO settlement, seasonal adequacy assessments, needs for new infrastructure remain at an early stage of development or have not yet been requested by transmission system operators.

In terms of performance, ACER encourages RCCs to:

• swiftly implement all their tasks and improve data quality;
• expand capacity calculation and security analysis across different timeframes and regions;
• focus on improving common grid model results to facilitate long-term readiness;
• enhance the scope of short-term adequacy, outage planning and training and certification of staff;
• align key performance indicators (KPIs) across regions; and
• issue recommendations as well as oversee their implementation. 

In terms of improving their reporting practices, ACER calls on RCCs to: 

• clearly distinguish between regional processes and pan-European ones;
• use common criteria and overview tables to present task implementation status; and
• further explain how the “rotation principle” is applied for pan-European tasks.

What are the next steps?

The next ACER monitoring report is scheduled for December 2026.

ACER intends to expand its monitoring to additional RCC tasks in the future. 

Check out ACER’s new RCC dashboard. 

On 3 December 2025, the national regulatory authorities of the Continental Europe Synchronous Area submitted to ACER a joint request for a six-month extension to decide on the transmission system operators’ proposal. This concerns the minimum activation period that frequency containment reserve providers with limited energy reservoirs must ensure in order to remain available during the alert state.

The countries of Continental Europe Synchronous Area are Austria, Belgium, Bulgaria, Croatia, Czechia, Denmark, Estonia, France, Germany, Greece, Hungary, Italy, Latvia, Lithuania, Luxembourg, the Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia and Spain.

What is it about?

EU’s electric power systems operate at the frequency of 50 Hz. Any imbalance between electricity supply and demand causes the frequency to deviate. If not corrected quickly, this can lead to blackouts.

Frequency containment reserve is the first line of automatic response to such deviations. It is activated within seconds to stabilise the frequency and is provided continuously by power-generating or consuming assets (like batteries, hydro plants or demand response systems). 

Some of these providers, especially batteries or demand-side resources, have limited energy reservoirs and can only respond for a short duration. The System Operation Regulation therefore requires a minimum activation time to ensure these resources remain available during the alert state. 

What are the next steps? 

ACER will review the regulators’ joint request and issue its decision by the end of January 2026. 

Update of 2 February 2026: On 30 January 2026, with its Decision 01/2026, ACER granted the extension requested by the NRAs, who have until 17 June 2026 to reach an agreement on the TSOs’ proposal.

ACER’s 2025 Monitoring Report on security of EU electricity supply looks at whether Europe had adequate electricity supply in 2024, including risk preparedness, cross-sectoral electricity-gas interactions and the total cost of national support measures such as capacity mechanisms and flexibility schemes that help keep the lights on.

What trends did ACER find in 2024? 

• The EU’s interconnected power system helps keep the lights on.
  • In 2024, power outage levels averaged under two hours per year across the EU, and none were due to inadequate electricity supply.
• Fragmented support measures come with an annual price tag of €11 billion.
  • Almost €11 billion was spent in 2024 across the EU on a fragmented set of nearly 40 security-of-supply measures.
  • Capacity mechanisms are justified if the annual European Resource Adequacy Assessment (ERAA), or alternatively a national assessment, identifies a risk of inadequate supply. Any capacity mechanism must be cleared by the European Commission under State aid rules. These mechanisms rely on a broad range of technologies from dispatchable gas-powered generation to batteries and demand response.
  • Member States can also introduce flexibility measures, again if cleared under EU State aid rules.
• Capacity mechanisms have yet to become cleaner, gas will still play a role.
  • Only 29% of capacity support was directed to low-emission technologies in 2024, while natural gas will lead in long-term contracts until 2035.
  • Although EU gas demand is expected to fall by 15% by 2035, gas-fired power plants are projected to cover 30% of peak demand.
• Capacity mechanisms have yet to become more efficient, coordination can help.
  • Capacity auction prices vary more than tenfold across the EU.
  • In 2024, capacity mechanisms cost €6.5 billion (more than double the cost in 2020). Stronger cross-border coordination could reduce additional capacity needs, lowering overall system costs.
  • Limited coordination in Member States’ adoption of capacity and flexibility measures could risk duplication and inefficient investment.
• Regional and cross-sectoral coordination on risk preparedness remain weak.
  • Only 10% of national risk preparedness plans include joint measures to mitigate the impact of electricity crises and assist neighbouring countries.
  • Cross-sectoral dependencies (i.e. between gas and electricity) are often overlooked.

What are ACER’s recommendations? 

• Make capacity mechanisms cleaner by removing barriers to distributed energy, enable demand response and disclose how much capacity support goes to fossil-fuels.
• Make capacity mechanisms more efficient, coordinating capacity planning at EU level and reassessing the design of capacity auctions, particularly in markets with consistently high prices.
• Integrate flexibility measures into capacity mechanisms or better align them to reduce overlaps and inefficiencies.
• Strengthen regional cooperation on risk preparedness through exchange of best practices, shared templates and joint implementation monitoring.