In 2024, the revision of REMIT (Regulation on Wholesale Energy Market Integrity and Transparency) introduced new data reporting requirements, including the obligation to report exposure data, which shows how much market participants are exposed to price movements in wholesale energy markets.

At the same time, broader initiatives such as the Clean Industrial Deal and the EC consultation on the functioning of commodity derivatives and spot energy markets highlight the importance  of simplifying and standardising data reporting.

As exposure data is a new and distinct reporting stream under REMIT, ACER will implement a new electronic template ‘Exposure XSD’ for its reporting, as set out in the revised REMIT and the recast REMIT Implementing Regulation.

Within this context, ACER is exploring whether the ‘ISO 20022 standard’, a common framework for exchanging data, could be applied to the ‘Exposure XSD’ reporting format, with the aim of making the reporting process simpler and more interoperable.

As a new reporting stream, the Exposure XSD is a suitable candidate that may benefit from the use of an existing standard. It is the only reporting format covered by this consultation, and no changes to existing REMIT reporting formats are being considered.

Your views matter

To support more harmonised reporting and to improve the interoperability of reported data, ACER will run a public consultation to gather input. Stakeholders are invited to share their views on the potential benefits of applying the ISO 20022 standard to the Exposure XSD reporting format. 

The public consultation will run from 12 January until 9 February 2026.

Next steps

Based on the input received, ACER will assess whether to proceed with adopting the ISO 20022 standard for the Exposure XSD electronic format.

Technical specifications and detailed guidance on how to report exposure data in line with REMIT Implementing Regulation will be addressed in a separate consultation, to be launched after the revised Regulation enters into force.

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.

Today, ACER releases its report on the Polish gas transmission tariffs directed at GAZ-SYSTEM S.A., Poland’s transmission system operator (TSO), which manages the country’s two transmission systems.

The report assesses the compliance of the proposed reference price methodology (RPM) with the requirements of the EU Network Code on Harmonised Transmission Tariff structures. 

What is the proposed tariff methodology?

The Polish TSO proposes to:

• Apply a postage stamp reference price methodology with a 50-50 entry-exit split, combined with discounts for LNG terminals, biomethane producers and gas storage facilities.
• Merge the two existing entry-exit zones of the National Transmission Network (NTS) and the Transit Gas Pipeline System (SGT), the two Polish transmission systems, into a single national zone with uniform tariff rules.
• Continue recovering allowed revenues for transmission services through capacity-based tariffs only, meaning users pay based on the network capacity they book, not the volume of gas they transport.
• Maintain the current two gas sub-systems (for low-methane and high-methane gas) within the NTS.
• Keep two non-transmission services (gas pressure reduction and gas compression) in place.

What are the key findings? 

After analysing the consultation document, ACER concludes that: 

• The proposed methodology meets EU requirements on transparency, cost-reflectivity, avoidance of cross-subsidisation, non-discrimination, volume risk and the prevention of cross-border trade distortions.
• Merging Poland's entry-exit zones will create a level playing field for all network users importing gas to the country.
• The Polish TSO considered ACER’s previous recommendations (for the NTS system and the SGT system), addressing past shortcomings and developing a methodology that complies with EU rules.

What does ACER recommend? 

ACER recommends that the Polish national regulator (URE), when adopting its final decision on the proposed methodology:

• Review the low-methane subsystem and assess costs and benefits of potential measures to better align it with EU requirements.
• Carry out some additional assessments and consider technical adjustments to fine-tune the methodology.

See all ACER reports on national tariff consultation documents. 

ACER publishes today its Opinion on the draft gas and hydrogen ten-year network development plan (TYNDP) 2024 submitted by the European Network of Transmission System Operators for Gas (ENTSOG) on 20 October 2025.

What is the TYNDP?

Every two years, ENTSOG publishes a TYNDP where it:

• identifies EU’s hydrogen infrastructure needs;

• assesses new infrastructure projects to ensure security of gas supply, market integration and competition. 

ENTSOG’s draft 2024 TYNDP provides a pan-European view on hydrogen infrastructure needs up to 2040, an assessment of the natural gas curtailments under various stress cases and lists promoters’ planned projects.

ACER’s role is to assess (in an Opinion to ENTSOG) the methodologies used in the TYNDP, its development process and outcomes as well as to provide suggestions for improvement.

ACER’s recommendations aim to support investment decisions and facilitate the efficient development of the European gas and hydrogen grid, in line with broader EU policy goals.

What are ACER’s main findings on the 2024 draft TYNDP?

ACER acknowledges several improvements:

• in the methodologies used for the TYNDP development;

• on how the Hydrogen Infrastructure Gaps Identification Report in the draft TYNDP reflects ACER’s  recommendations; 

• greater transparency regarding the technical information of the submitted projects; and

• clearer presentation of the results.

While recognising the complexity of the TYNDP process, ACER notes shortcomings:

• The late delivery of the 2024 TYNDP (submitted to ACER in Q4 2025) undermines the alignment with the selection of projects of common interest (PCIs) and projects of mutual interest (PMIs). PCIs and PMIs are both categories of cross-border energy infrastructure projects under the TEN-E Regulation. PCIs are located within the EU, whereas PMIs are between the EU and non-EU countries.

• Limited implementation scope: only one scenario of future possibilities was considered, and a cost-benefit analysis was conducted only for some projects.
• Insufficient data quality and transparency, including missing costs for many projects.

• Weak connection between Europe’s identified needs and the projects being proposed by project promoters.   

What are ACER recommendations? 

To finalise its 2024 TYNDP and prepare for future editions, ACER recommends ENTSOG to:

• Ensure a timely submission of the TYNDP by addressing the root causes of the recurring delays.

• Perform cost-benefit analyses for all scenarios and projects.

• Strengthen inputs, assumptions and cost data to ensure credible results.

• Improve transparency of project information and methodological choices.

• Make the plan needs-driven, with clearer justification for proposing the specific projects.

What are the next steps?

ENTSOG should take ACER’s recommendations into account to finalise the 2024 draft TYNDP and further improve its upcoming editions.

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.