ACER publishes its Opinion on the Summer Supply Outlook 2025 prepared by the European Network of Transmission System Operators for Gas (ENTSOG).

The Summer Outlook evaluates the ability of the EU’s gas system to meet demand and handle storage injections during the upcoming summer and winter seasons.

The expected gas demand and supply projections are modelled under a reference scenario, which is complemented with various challenges to the gas system (such as cold winters and disruptions in Russian gas supply). 

What are the 2025 Summer Outlook’s main highlights?

The Outlook examines the EU’s dependence on Russian gas supply:

• In all scenarios, gas imports via the TurkStream pipeline (running from Russia to Turkey) are minimised.
• Two additional Russian gas disruption scenarios are modelled: a complete disruption of TurkStream and a 20% reduction of liquefied natural gas (LNG) supply.

In all scenarios, the Outlook concludes that the current European gas infrastructure is adequate to ensure security of gas supply.

These scenarios broadly align with the recent proposal by the European Commission to coordinate a gradual phase-out of Russian gas imports by stopping existing spot contracts by mid-2026, with the aim of ending all remaining gas imports by the end of 2027.

What’s in the ACER Opinion?

ACER welcomes the timely publication of ENTSOG’s Summer Outlook (April 2025), the modelling updates to reflect recent changes in infrastructure (e.g. new LNG terminals and cross-border capacities) and to cover the potential EU gas transit via Ukraine. ACER also suggests further improvements to the Outlook’s future editions:

• Include a gradual phase-out of Russian gas supply in a sensitivity scenario, reflecting the roadmap of the European Commission.
• Focus on LNG import trends, as the increasing global LNG market expansion is influenced by geopolitical instabilities (e.g. the current conflict in Iran may impact gas supply and price due to the country’s strategic location for energy exports).
• Review transmission system operators’ demand estimates by comparing them with past demand, political and economic trends, as well as with third-party projections.
• Explore the impact of gas prices on gas supply and storage filling, as it may alter the typical supply pattern. This would provide a more realistic assessment of the gas system in the coming year.

ACER publishes a new report and updates its interactive dashboard to showcase main gas balancing trends in the EU for the 2023-2024 gas year. 

Keeping Europe’s gas systems balanced efficiently

The Gas Balancing Network Code establishes market-based rules to ensure efficient balancing of gas supply and demand in European gas balancing zones. For example, it establishes rules that enable and incentivise network users to balance their positions. It also promotes the development of short-term markets by prioritising the use of standard wholesale products when transmission system operators (TSOs) need to manage any remaining system imbalances.

What’s the role of ACER?

Each year, ACER analyses data collected by the European Network for Transmission System Operators for Gas (ENTSOG) to monitor the implementation and effects of the Gas Balancing Network Code across Member States, focusing on:

• TSOs’ balancing activities;
• network users’ imbalances;
• neutrality (i.e. the cost or revenue generated by the balancing regime).

What does ACER monitoring show? 

• TSOs’ balancing actions have declined across most EU gas balancing zones: These interventions accounted for a decreasing share of the physical gas market at EU level.
• The changing gas market may be reducing the need for balancing. Lower gas consumption and a smaller physical market may have reduced the need for TSOs to actively balance the system. At the same time, higher gas prices may further incentivise users to stay in balance and avoid charges.

What does ACER recommend? 

ACER encourages national regulatory authorities to:

• Periodically review the performance of their balancing regimes and assess whether their design should be refined or revised.
• Ensure that incentives for commercial balancing are adequate and explore enhancements to information systems to facilitate network users’ participation.

ACER monitoring, together with market participants’ views (identified through public consultations) and regional cooperation can support regulators in these processes.

ACER is establishing a new European Stakeholder Group on demand response in the electricity sector. We invite associations that could offer a pan-European perspective on electricity markets to join. 

What’s the background?

On 7 March 2025, ACER submitted its proposal for a new EU-wide network code on demand response to the European Commission, in line with its framework guideline.

ACER’s proposal sets out common rules to ensure that demand response resources (such as consumers, storage providers and distributed generation) can fully participate in wholesale electricity markets, providing flexibility to the grid.

To support the implementation of these rules, ACER committed to coordinating stakeholder engagement on demand response topics by establishing a new dedicated European Stakeholder Group.

What will the demand response group do? 

The Demand Response European Stakeholder Group (DRESG) will act as an EU-level platform where ACER, the European Network of Transmission System Operators for Electricity (ENTSO-E) and the EU Distribution System Operators Entity (EU DSO Entity) engage with stakeholders on key matters of demand response. The group will focus on:

• discussing proposals for terms and conditions or methodologies required by the new network code;
• addressing broader issues related to demand response; and
• supporting the practical implementation of the network code.

Through this new stakeholder group, participating associations will:

• Monitor the implementation progress of the code, including how newly established processes function at local, regional and EU level.
• Share views and feedback on the code’s implementation, ensuring stakeholder input is taken into account.
• Support more informed decision-making on the methodologies and rules to be developed under the code.

By doing so, the group will support the flexibility required by the EU electricity system (increasingly powered by renewable energy), strengthening energy security and advancing the EU’s transition to clean energy.

Who can join?

Associations that could offer pan-European views on demand response in electricity markets are encouraged to apply. Bring your insights to the table and ensure that your voice shapes the future of demand response!

Deadline to apply is 15 August 2025, with the first meeting planned for October 2025. See how to apply.

See the Terms of reference for the demand response stakeholder group.

ACER publishes today its Consolidated Annual Activity Report for 2024, which details the Agency’s regulatory activities in relation to:

• the ongoing integration of Europe’s electricity and gas markets;
• market surveillance under the Regulation on Wholesale Energy Market Integrity and Transparency (REMIT) and its revision (May 2024).

The report assesses the extent to which ACER met the objectives of its 2024 work programme and addresses internal management and governance matters. It was adopted by ACER's Administrative Board on 6 June 2025, following approval by ACER's Board of Regulators.

What were the main developments in 2024?

Electricity markets:

• The process to develop a recommendation for the EU network-code on demand response was initiated (concluded in March 2025). The network code aims to empower consumers and aggregators and provide more flexibility to the EU electricity system.
• A joint ACER-CEER paper (June 2024) was published, identifying five key challenges for the electricity system.
• Continued monitoring Member States’ delays in implementing harmonised market rules.
• A new EU-wide tool to assess system flexibility needs was procured.

Security of supply and adequacy:

• The European Resource Adequacy Assessment (ERAA) 2023 was adopted. For the first time since 2020, the comprehensive EU-wide adequacy assessment (which identifies potential capacity gaps through 2024) was approved.
• ACER monitoring report on security of EU electricity supply was published, comparing national and EU-level adequacy calculations to inform capacity-mechanism decisions.

Gas monitoring and infrastructure:

• Quarterly gas monitoring reports and a dedicated LNG outlook were released, analysing price trends, volatility drivers and supply flows.
• Expert advice was offered to the European Commission on the revised network code for capacity allocation mechanisms, aimed at aligning tariffs with wider decarbonisation and flexibility goals.
• Joint work with CEER on an EU-wide electricity infrastructure report.

Hydrogen market:

• ACER’s first hydrogen market monitoring report was published in November 2024, assessing regulatory frameworks, supply and demand forecasts and infrastructure needs.
• ACER provided its Opinion on the legal setup of the European Network of Network Operators for Hydrogen (ENNOH).

REMIT enforcement and market surveillance:

• Approximately 12 billion transaction records were processed from 106 reporting parties. Coordination of national investigations resulted in fines of about €122 million.
• Continued operation of the Market Correction Mechanism (MCM) for daily EU gas reference pricing.
• A new REMIT Investigations department was established to handle cross-border abuse cases. 
• Support to the European Commission was provided in drafting REMIT II implementing acts.

Access previous editions.

On 9 May 2025, the Swedish and Lithuanian national regulatory authorities (Energy Markets Inspectorate and National Energy Regulatory Council, respectively) requested from ACER a six-month extension to jointly decide on electricity cross-zonal risk hedging opportunities.

What are cross-zonal risk hedging opportunities? 

Cross-zonal risk hedging opportunities are strategies used by electricity market participants to mitigate price volatility risks across different bidding zones. They are important to ensure the proper functioning of the EU’s wholesale electricity markets and protecting market participants from price uncertainty.

Why an ACER Decision?

In accordance with the Forward Capacity Allocation network code, the Swedish and Lithuanian national regulators tasked transmission system operators to propose alternative measures to improve cross-zonal hedging opportunities in the Lithuanian bidding zone. 

The Swedish and Lithuanian transmission system operators submitted a joint proposal to their national regulators, but it contained some ambiguities. 

Therefore, both regulators requested ACER additional time to assess the system operators’ proposal. According to the ACER Regulation, ACER is mandated to grant this extension.

ACER intends to act promptly on this request, aiming to reach a decision by the end of September 2025.

ACER and the national regulatory authorities of Austria, Germany and the Netherlands have closed the cross-border investigatory group established in 2022.

This group was set up under REMIT (the EU framework to prevent energy market abuse, ensuring transparency and integrity) in response to the exceptional conditions during the energy crisis – unprecedented high prices, high volatility, and scarce electricity and gas supplies – to enhance monitoring and detection of potential market abuse.

The group aimed to strengthen coordination and support evidence gathering in a complex case involving multiple potential REMIT breaches in the wholesale gas market.

The case spanned several countries. ACER initiated the process by sharing a preliminary report with the relevant regulators, based on suspicious patterns flagged during its EU-wide market surveillance. The national regulatory authorities of Austria, Germany and the Netherlands have worked closely together in their investigatory activities, and coordinated on which national regulatory authorities would take on the lead in a formal investigation and which ones would assist. The Dutch regulator provided assistance in the investigatory activities.    

The coordination of investigative activities and the collection of the necessary evidence have led to the following outcomes: 

• Austria: The Austrian regulator identified several potential REMIT breaches and submitted two formal investigation reports to the national enforcement authority. However, the authority decided not to pursue the case further. 

• Germany: The German regulator opened a formal investigation into another potential REMIT breach involving the same market participant. This investigation is ongoing, and cooperation will continue under a lighter, more flexible arrangement. 

As the main objectives were met (sufficient evidence was gathered to pursue the case at the national level), this group has now concluded its work. 

What happens next?

This effort underscores the importance of strong investigatory and enforcement powers at national level to uphold market integrity. ACER and national regulators continue to cooperate closely to support the effective enforcement of REMIT.

Neither ACER nor the NRAs can comment on past or ongoing REMIT investigations.

Roles of ACER and national regulators under REMIT

• ACER’s role: ACER monitors wholesale energy markets across the EU, collects data, issues guidance, and coordinates national regulatory authorities’ activities to ensure a coherent application of REMIT and an effective approach to tackling market abuse. A cross-border investigatory group is an administrative arrangement established by ACER to coordinate investigations by NRAs into a potential market abuse case under REMIT. As of May 2024, under the revised REMIT regulation, ACER can also conduct investigations into certain cross-border cases.

• National regulatory authorities: National regulators are responsible for investigating suspected cases of insider trading or market manipulation and enforcing REMIT through sanctions and remedies defined by national law.

Access the table of REMIT breach sanction decisions adopted by national regulators. 

ACER issues today its guide on benchmarking the costs and effectiveness of cybersecurity investments in the EU electricity sector.

This ACER guide is developed under the binding EU-wide network code on sector-specific rules for cybersecurity aspects of cross-border electricity flows. It aims to help national energy regulators conduct the benchmarking required by the network code.

Why is this benchmarking important?

Conducting benchmarking of cybersecurity investments will provide national regulatory authorities with an overview of:

• the costs of implementing cybersecurity controls, as well as their effectiveness and efficiency;
• prices of cybersecurity services, systems and products;
• the level of comparability of costs and functions of cybersecurity products and services. This analysis will also help identify possible opportunities to increase spending efficiency.

This will be the first EU-wide analysis on the topic.

What does ACER recommend?

ACER encourages national regulators to follow ten principles when conducting this benchmarking:

• Plan and execute benchmarking activities to ensure results can serve their intended purpose.
• Limit the scope and complexity of information to what is required by the benchmarking analysis.
• Use a consistent approach when conducting national analyses.
• Identify the stakeholders that will provide the data required by the benchmarking.
• Develop reference lists of items for the purpose of benchmarking. For example, considering assets that are relevant for Union-wide high and critical impact processes.
• Apply general accounting principles to assess the costs of benchmarked items.
• Include macroeconomic factors (e.g. inflation) in the analysis.
• Simplify how the effectiveness of investments is evaluated, considering this benchmarking assessment does not require the same level of detail as security assessments.
• Evaluate the effectiveness of cybersecurity investments following the benchmarking objectives of the network code.
• Explore different approaches for comparing the costs and functions of cybersecurity products and services.

What’s next?

From today’s publication, national regulatory authorities have one year to carry out the cybersecurity benchmarking analysis. 

ACER releases today its Opinion on the hydrogen Infrastructure Gaps Identification (IGI) report 2024. ACER welcomes the publication of this report prepared by the European Network of Transmission System Operators for Gas (ENTSOG), providing recommendations to improve the underlying methodology.

What is the hydrogen Infrastructure Gaps Identification report?

Hydrogen is expected to play a key role in achieving the EU’s climate and energy goals. However, its market is still in the early stages, with low renewable hydrogen production and consumption, and slow infrastructure buildout. High production costs and uncertain demand are hindering market development. Unlike electricity, hydrogen also lacks a well-developed transmission network, making infrastructure planning more complex and highly dependent on policy support and demand forecasts.

To address these challenges and support coordinated planning and investments, ENTSOG published the first hydrogen Infrastructure Gaps Identification report in March 2025. This report is part of the EU’s Ten-Year Network Development Plan (TYNDP) framework and aims to identify regional gaps in hydrogen infrastructure based on demand and supply projections for 2030 and 2040.

What does ACER recommend? 

While ENTSOG’s report highlights bottlenecks that could signal potential infrastructure shortages, ACER recommends improving the methodology used to better identify these gaps by: 

• Incorporating scenario variants to understand how projected infrastructure needs change under different assumptions. This would help identify the risk of investments that do not align with future hydrogen demand.

• Refining the analysis to better determine where and how much additional cross-border infrastructure capacity is needed. 

• Seeking a more cross-sectoral modelling approach to capture the interdependencies between hydrogen infrastructure and electricity systems more effectively.

What’s next?

ACER encourages ENTSOG to start testing the suggested improvements using the data currently available, without waiting for the upcoming 2026 TYNDP scenarios. Early testing can help enhance the methodology used to identify future needs, prevent delays and reinforce trust in the ensuing results.

Bidding zones are geographical areas where electricity is traded at uniform prices. Within a bidding zone, electricity bids and offers from market participants can be matched without the need to allocate cross-zonal capacity. Currently, most bidding zones in the EU are defined by national borders.

Under the EU Electricity Regulation, bidding zones must be configured in a way that maximises economic efficiency and cross-zonal trading opportunities, while ensuring security of supply. To achieve this, a review of the existing bidding zones was needed to identify structural grid congestions and evaluate the potential benefits of alternative configurations.

On 28 April 2025, European transmission system operators (TSOs) published their report on the electricity bidding zone review study. The report, which assesses 14 bidding zone configurations across Central and Northern Europe, is intended to support EU Member States in deciding whether to amend or maintain the current bidding zone configurations.

What is ACER’s role in the process?

ACER is responsible for setting the methodology and identifying alternative bidding zone configurations for TSOs to consider in their review.

Hence, in November 2020, ACER issued a decision establishing the bidding zone review methodology. In August 2022, ACER published a second decision on the alternative bidding zone configurations to be considered for Central Europe (Germany, France, Italy and the Netherlands) and the Nordic region (Sweden). A third decision, covering the Baltic region, was issued in December 2023.

As part of its mandate under the ACER Regulation, ACER will also publish an Opinion (addressed to the Council) to assess whether electricity system operators followed the agreed methodology in their bidding zone review study and evaluate the impact of any deviations.

What are the next steps? 

ACER aims to publish its Opinion by the end of September 2025. Update: ACER published its Opinion on 18 September 2025.

Following the publication of the TSOs’ bidding zone report, Member States have six months to decide whether to amend the existing bidding zones. If individual Member States wish to amend their bidding zone configuration, but no unanimous agreement is reached among the relevant parties, the European Commission (after consulting ACER) will have six months to decide.

ACER is establishing a new European Stakeholder Committee (ESC) on cybersecurity in the electricity sector. We invite industry associations that could offer a pan-European perspective on cybersecurity aspects of cross-border electricity flows to join. 

What’s behind this?

The Network Code for Cybersecurity for Electricity came into force in June 2024. It sets out common rules to boost cyber resilience across Europe’s power systems. It calls for ACER to coordinate stakeholder engagement, in close collaboration with the European Network of Transmission System Operators for Electricity (ENTSO-E) and the EU Distribution System Operators Entity (EU DSO Entity).

What will the cybersecurity committee do?

Through this new ACER cybersecurity committee, industry associations will cooperate with each other and with the authorities referred to in the Cybersecurity Network Code to:

• identify problems and propose improvements to the implementation of the existing cybersecurity network code;
• recommend future revisions of the network code;
• identify whether any additional risk prevention rules may be needed for the electricity sector; and
• respond to technological developments in the sector.

By tackling these points, the cybersecurity committee will help maintain a high, common level of cyber resilience in Europe’s electricity grid and adapt policy to evolving digital risks.

Who can join?

Industry associations that could offer pan-European views on cybersecurity aspects of cross-border electricity flows are encouraged to take part. It is a chance to bring your insights to the table and ensure the voice of industry shapes the future of electricity cybersecurity in Europe.

Deadline to apply is 2 July 2025, with the first meeting planned for early autumn 2025. See how to apply.

See the Terms of reference for the cybersecurity committee for electricity.