Today, ACER publishes its Recommendation on how national regulatory authorities (NRAs) should report barriers to non-fossil flexibility. The document provides clear guidance and indicators to ensure consistent reporting across Member States and help NRAs and relevant entities evaluate these barriers as part of their flexibility needs assessments.

What is non-fossil flexibility? 

Non-fossil flexibility is the energy system’s ability to quickly adapt to changes in electricity supply and demand, without relying on fossil fuels or costly grid expansions. It does so by shifting electricity consumption or generation to times or locations where the system is less constrained.

Unlocking flexibility helps foster a more efficient electricity system, supports the integration of renewables and contributes to lowering consumer bills. 

Why an ACER Recommendation?

The EU Electricity Regulation requires Member States to carry out flexibility needs assessments to determine how much clean flexibility their electricity systems require, including identifying existing barriers. These national assessments are harmonised across the EU through a common methodology approved by ACER in July 2025. 

This ACER Recommendation complements this process, by: 

• Setting out clear guidance on which barriers, indicators and evaluation methods Member States may consider when preparing their assessments.
• Streamlining the assessment process, consolidating ACER’s prior work on barriers (2023 and 2025) across all types of non-fossil flexibility and incorporating stakeholder input (winter 2023-2024).
• Ensuring comparable reporting across countries, supporting ACER’s forthcoming EU-wide analysis of barriers to clean flexibility identified in national assessments.

What does ACER recommend? 

ACER recommends that NRAs, in coordination with relevant entities, consider the main barriers to non-fossil flexibility when drafting their national reports. These include:

• Lack of proper legal framework for households, new entrants or aggregators to participate in electricity markets and system operation services.
• Lack of enablers and incentives for flexibility, such as smart meters and flexible retail contracts that help consumers shift their consumption.
• Restrictive rules to provide balancing and congestion management services.
• Complex, lengthy and discriminatory administrative requirements, including inefficient grid connection processes.
• Limited regulatory incentives for system operators to invest in non-wire, innovative grid technologies. 

What are the next steps? 

Member States are expected to complete their flexibility needs assessments by July 2026. ACER will then have a year to analyse the findings and publish an EU-wide analysis to:

• estimate flexibility needs across the EU;
• evaluate existing barriers to clean flexibility, including those identified in national assessments; and
• provide recommendations on issues of cross-border relevance (including measures to remove barriers to non-fossil flexibility).

Today, ACER publishes its Decision amending the European Resource Adequacy Assessment methodology, following the proposal submitted by the European Network of Transmission System Operators for Electricity (ENTSO-E) in November 2025.

What is the methodology about?

The ERAA, mandated by the Clean Energy Package (2019), is ENTSO-E’s annual assessment of the EU’s electricity supply adequacy for the next decade. Its purpose is to evaluate whether the EU has sufficient electricity resources to meet future demand and to identify potential risks to security of supply. Each year, the assessment is subject to ACER approval.

At national level, Member States define their own reliability standards (based on ACER’s methodology) to set the level of security of electricity supply they require. The ERAA annual assessment provides a consistent, objective tool to evaluate adequacy risks against those standards and whether the introduction of national measures (such as capacity mechanisms) is needed.

Why amend the methodology?

In its streamlining report (March 2025), the European Commission requested ACER to amend the ERAA methodology to streamline the capacity mechanisms’ approval process. ACER subsequently required ENTSO-E to propose the necessary amendments.

In August 2025, the Commission also adopted the Clean Industrial State Aid Framework, which introduces a fast-track process for approving capacity mechanisms. To support this framework, the ERAA methodology needs to define the procedure for calculating, within the ERAA annual process, the parameters necessary for Member States to make use of the fast-track approval process.

What are the main amendments?

The updated ERAA methodology focuses on:

1. Supporting capacity mechanisms approval

• Introducing capacity mechanism-related parameters derived from the ERAA model, which Member States may use to benefit from the fast-track process.

These parameters:

• improve the clarity of ERAA results by quantifying the size of the adequacy concern (adequacy gap and total firm capacity needs) and how different technologies contribute to system adequacy (de-rating-factors);
• can be used by Member States to size their capacity mechanisms (when applying for fast-track approval).

2.  Simplifying the methodology 

• Focusing the model on key target years (instead of explicitly modelling every year of the next decade).
• Introducing simplified approaches for key methodological components (e.g. estimating flexibility resource revenues and developing scenarios that reflect the impact of capacity mechanisms across Europe).
• Streamlining how Member States’ efforts to avoid regulatory distortions or market failures are represented in the ERAA.

3.   Improving adequacy modelling 

• Developing a new Trends and Projections scenario to better reflect the actual pace of the energy transition.
• Improving the modelling of investors’ risk aversions and introducing a more realistic representation of flexible resources’ (e.g. batteries and demand response) business case.

What are the next steps?

ENTSO-E will progressively integrate the amended ERAA methodology into future ERAA reports (starting with the upcoming 2026 edition). As part of this implementation, capacity-mechanism-related parameters will be introduced in the ERAA framework. These parameters will help improve coordination of capacity mechanisms across Europe, increase their efficiency and help reduce costs for consumers.

Based on the ERAA results, Member States may also use these parameters when applying for the fast-track approval process for capacity mechanisms.

The image shows how coordinating capacity mechanisms across EU borders reduces procurement needs and lowers costs for consumers. Source: ACER Monitoring Report on security of EU electricity supply (2025).

ACER kicks off its 2026 Monitoring Report series with key insights into the EU energy markets, highlighting major developments in 2025 and examining the interplay between gas and electricity markets in the energy transition.

What are the key findings?

The report shows solid progress in Europe’s clean energy transition. It also underlines persistent structural challenges (such as price volatility, system flexibility and supply risks) and how to address them.

• Wholesale energy prices continued to decline, but global competitiveness remains a challenge, with both gas and electricity prices structurally higher than in the US.
• Household gas and electricity prices remain high despite falling wholesale prices.
• Renewables lead the power mix, providing 50% of total EU electricity generation. Solar drives the energy transition, with investments in solar generation rising by 41 TWh compared to 2024. 
• Electricity price volatility increased: Daily wholesale power price swings were around five times higher than in 2020, highlighting the growing need for flexibility. 
• Gas provides evening flexibility: As solar generation drops in the evening, gas-fired power plants are increasingly used to meet demand, pushing wholesale prices upward.
• Extreme weather drives price spikes: A heatwave on 1 July 2025 reduced cooling efficiency at thermal and nuclear plants, pushing power prices in Poland to around 470 EUR/MWh. 
• Regional price differences highlight the value of interconnections: Different generation mixes and system flexibility across countries offer opportunities when systems are well interconnected. 
• Gas markets remained stable, with hub spreads generally below 2 EUR/MWh.
• EU slashed its reliance on Russian gas, replacing it with global LNG: Russian pipeline imports to the EU fell by about 162 TWh compared to 2024 and were fully offset by record-high LNG imports.
• Low year-end gas storage: Heavy winter withdrawals left storage levels 10% below 2024.

What are ACER’s recommendations? 

To support global competitiveness and decarbonisation, Europe should step up efforts to expand energy market integration:

• Make energy prices more efficient and transparent: Ensure efficiency across all price components (energy and supply, network charges and taxation) to improve household affordability and industrial competitiveness.
• Harness flexibility: Expand demand response, electric vehicles (EVs) and battery use to balance supply and demand, reduce price swings and strengthen grid resilience.
• Strengthen market integration: Expand interconnections to support cross-border use of renewables, reduce fossil fuel dependence and improve system flexibility and security.
• Diversify gas supply: Higher LNG supplies replaced Russian pipeline gas but increased reliance on US LNG imports. Greater supply diversification, including domestic decarbonised gases, would reduce vulnerability and mitigate the impact of global price volatility.
• Reduce reliance on conventional gas: With gas consumption still well above 2030 targets, further action is needed to cut demand and accelerate the uptake of renewable gases.

On 31 March 2026, ACER will open a public consultation on developments in the EU Power Purchase Agreements (PPAs) market. The aim is to identify existing initiatives and challenges faced by market participants across Member States.

What are Power Purchase Agreements (PPAs)?

PPAs are long-term contracts between electricity producers (often renewable energy generators) and buyers. By providing renewable electricity at mutually agreed rates, these contracts foster long-term price stability and investment predictability for both parties. This helps reduce exposure to market volatility and encourages investments in renewable energy, limiting reliance on subsidy schemes. 

Under the revised Renewable Energy Directive, Member States are required to facilitate the uptake of renewable PPAs by removing unjustified barriers and disproportionate or discriminatory practices. However, the availability and functioning of these contracts vary significantly across the EU due to different national regulatory frameworks and financing mechanisms.

Why consult?

ACER is responsible for monitoring the PPAs market and publishing an annual assessment of its development at both EU and Member State level. 

To this end, ACER is launching a consultation to identify key regulatory, market and financial factors affecting the development and functioning of PPAs across Member States.

Get involved!

The public consultation will run from 31 March to 8 May 2026.

Feedback received will inform ACER’s 2026 annual assessment of the EU PPAs market.  

On 27 February 2026, ACER will open a public consultation on economic input data to improve electricity system modelling across Europe. The aim of this consultation is to ensure that the inputs used in European-level modelling are robust, transparent and properly grounded in national market realities.

Why are we consulting?

Realistic cost assumptions are key for effective long-term electricity system modelling, including the one used by ENTSO-E for the European Resource Adequacy Assessment (ERAA). These models are used to assess future investment needs, such as whether new power generation or flexibility resources are likely to be built, and whether existing power plants are expected to remain economically viable.

ACER has recently commissioned a consultancy study on investment parameters. As part of it, the consultant delivered a comprehensive EU-wide economic dataset for electricity system modelling. This new dataset shows estimated investments and operational costs for different power generation technologies and demand-side flexibility at Member State level.

Get involved!

Stakeholders are encouraged to review the data for their relevant Member State(s), assess whether it reflects current market and technological developments and propose evidence-based alternatives. 

The consultation will run from 27 February 2026 until 27 March 2026.

What’s next?

These figures will help shape how Europe’s power system develops in the years ahead.

ACER will examine the feedback received and revise the dataset to ensure accuracy and credibility. The finalised data will then be used to improve future ERAA modelling by ENTSO-E, as well as to help Member States in the procedure of fast-track approval of capacity mechanisms under the new State aid framework.

ACER will consult on amendments to the long-term capacity calculation methodology of the Core capacity calculation region (CCR) from 27 February until 27 March 2026.

On 21 November 2025, the Core CCR’s transmission system operators (TSOs) submitted a proposal to their national regulatory authorities (NRAs) to amend the long-term capacity calculation methodology. As the NRAs could not reach an agreement, the proposal was referred to ACER on 4 February 2026 under the Forward Capacity Allocation Regulation. 

The Core CCR comprises 13 countries: Austria, Belgium, Czech Republic, Croatia, France, Germany, Hungary, Luxembourg, the Netherlands, Poland, Romania, Slovakia and Slovenia.

What is the methodology about?

Long‐term cross-border capacity calculation promotes efficient long‐term cross‐zonal trade. By providing reliable capacities to market participants early, it enables long-term planning and hedging opportunities.

The Core CCR’s long-term methodology covers both yearly and monthly processes, using the flow-based approach.

Why change it?

In their proposal, TSOs recommend to:

• Introduce a benchmark process for available transfer capacity, adjusting the flow-based capacity calculation to better reflect historical cross-border transmission capacities.
• Integrate the Ireland and Northern Ireland single electricity market - France bidding zone border into the Core CCR’s long-term capacity calculation process, once the Celtic interconnector is commissioned.

The proposed changes aim to improve long-term capacity calculation in the Core CCR by enabling the implementation of the flow-based methodology. As a transitional measure, the benchmark for available transfer capacity would be applied at the end of the process. This would allow the yearly auction at the end of 2026 (for delivery in 2027), as well as the monthly auctions in 2027, to take place.

The inclusion of the Ireland and Northern Ireland single electricity market – France bidding zone border reflects its recent integration into the Core CCR. 

What are the next steps?

ACER aims to reach a decision by 4 August 2026. The Core TSOs shall implement the long-term capacity calculation methodology by the end of 2026.

In August 2025, ACER has received a proposal from Nominated Electricity Market Operators (NEMOs) to amend the harmonised maximum and minimum clearing price (HMMCP) methodologies for the EU day-ahead and intraday market coupling.

On 4 February 2026, ACER has approved NEMOs’ proposal.

Why is market coupling important?

Before market coupling was introduced in the EU, electricity and cross-zonal transmission grid capacity had to be purchased separately. Today, market coupling (of day-ahead and intraday markets) allocates scarce cross-zonal transmission grid capacity efficiently by coupling wholesale electricity markets across the EU, while taking into account physical grid constraints.

What are the methodologies about?

The HMMCP methodologies (first approved by ACER in 2017 and amended in 2023) set the maximum and minimum price limits in the EU single day-ahead and intraday electricity markets. 

Established under the Capacity Allocation and Congestion Management (CACM) Regulation, the methodologies also define the harmonised automatic price adjustment mechanism and specify how it is triggered when the applicable price limits are reached in the day-ahead and intraday markets. 

Why amend the methodologies and what’s new?

ACER amended the methodologies to clarify how the automatic price adjustment mechanism applies in rare market conditions.

In case of partial decoupling within a bidding zone where multiple NEMOs operate but not all are decoupled, the bidding zone will remain in market coupling, potentially with low liquidity. The amended methodologies clarify that, in such cases, the harmonised automatic price adjustment mechanism cannot be triggered. 

What are the next steps? 

Following this ACER Decision, NEMOs are required to promptly implement the amendments. 

Today, ACER publishes its Opinion on the Integrated Model report for EU electricity, gas and hydrogen infrastructure planning, submitted in October 2025 by the European Network of Transmission System Operators for Electricity (ENTSO-E) and for Gas (ENTSOG) and prepared with support from the European Network of Network Operators for Hydrogen (ENNOH).

The Trans-European Energy Infrastructure (TEN-E) Regulation requires ENTSO-E and ENTSOG to jointly develop a consistent and progressively integrated model to support coordinated infrastructure planning across the three sectors (electricity, gas and hydrogen), and underpin future EU-level Ten-Year Network Development Plans (TYNDPs).

Why is an integrated modelling framework needed for EU energy infrastructure planning?

Europe’s energy transition is increasingly blurring the boundaries between electricity, gas and hydrogen systems. Decisions in one sector directly affect infrastructure needs and costs in the others. To address this, EU law requires a shift from isolated, single-sector planning towards more coherent sectoral integration of the modelling governance, processes, tools and data used in electricity, gas and hydrogen network planning.

Such an integrated modelling framework aims to ensure that EU infrastructure plans are based on consistent assumptions, aligned methodologies and comparable cross-sector assessments. It should future-proof planning and inform project-level investment decisions from a system-wide perspective.

What does ACER say about the proposed integrated modelling framework for energy infrastructure planning?

ACER’s Opinion assesses whether the ENTSOs’ submission provides a sufficiently robust basis for more coherent, cross-sector infrastructure planning at EU level.

The report is a useful starting point, with some progress beyond joint scenario development, including the creation of a dedicated cross-sector working group with balanced representation across the three sectors.

However, ACER finds the report does not clarify how the integrated modelling framework will contribute to greater consistency and integration of EU infrastructure planning through concrete milestones. The report falls short in the following areas:

• Cross-sector integration requirements are unclear, leaving implementation discretionary.
• Key integration steps are deferred to a long-term roadmap with vague timelines and under-ambitious actions.
• Stakeholder consultation was limited, with key elements excluded (draft report and roadmap).

As a result, it remains unclear whether the proposed framework will deliver practical improvements in infrastructure needs assessments, investment decision-making or system-wide cost optimisation.

What does ACER recommend?

For better EU infrastructure planning, ACER calls on ENTSO-E and ENTSOG, together with ENNOH, to be more ambitious in their approach to integrated modelling:

• Clearly define assumptions, data and methodologies to be applied consistently across sectors.
• Identify which planning steps require joint cross-sector assessment and which can remain sector-specific.
• Apply shared reference networks and indicators in project-level cost-benefit analyses (CBAs).
• Strengthen consistency in identifying infrastructure gaps.
• Ensure cross-sector needs assessments and harmonised CBA pilots are conducted within the TYNDP 2028 cycle.
• Update the roadmap with more ambitious actions and firmer timelines.
• Conduct a more thorough public consultation on the revised model and roadmap.

ACER expects that consistency in input, assumptions and methodology is already applied in TYNDP 2028, even if some deliverables remain sector-specific.

What are the next steps?

ACER expects ENTSO-E and ENTSOG to implement these recommendations before submitting the report to the European Commission for approval. ACER calls for early and meaningful stakeholder engagement as the integrated modelling framework evolves.

ACER issues today its guidance on the information to be voluntarily submitted for the monitoring of operational reliability performance indicators related to cybersecurity in the electricity sector, under the Cybersecurity Network Code. 

Who is this guidance for?

This guidance is addressed to stakeholders in the electricity sector, including transmission and distribution system operators (TSOs and DSOs), generators, organised markets, nominated electricity market operators (NEMOs) and balancing responsible parties, as well as providers of critical information and communication technology (ICT) services and managed security services.

Why does it matter?

The operational reliability performance indicators for cybersecurity will measure how effectively electricity sector companies protect their digital systems and mitigate cybersecurity risks to cross-border electricity flows. They will track statistical data on high and critical-impact cyber-attacks, reportable cyber-threats and exploited unpatched vulnerabilities.

By submitting the requested data, stakeholders will allow ACER to monitor trends and assess how cybersecurity performance evolves across the EU electricity sector. 

What information is ACER requesting?

ACER is requesting the following statistical information, as defined by the operational reliability performance indicators listed in the guidance:

• annual number of reportable cyber threats;
• annual number of reportable cyber-attacks; and
• annual number of exploited unpatched (zero day) vulnerabilities.

What’s the timeline to submit the information?

Starting in 2027, ACER will open a submission window once every three years. In the first submission window in 2027, ACER will request data for 2026. From 2030 onwards, each submission will cover the three preceding years.

Unless communicated otherwise, the submission window will be open each reporting year from 15 January to 1 March. 

How will the information be submitted?

To facilitate data collection, ACER will provide access to a secure online tool. More detailed instructions will be made available prior to the first submission window.

What are the next steps? 

Looking ahead, ACER will use this collected data (after careful aggregation to protect sensitive information) as an input to its triannual reporting, supporting EU-level monitoring and informing future efforts to strengthen the EU cyber resilience.

Today, ACER publishes a position paper introducing output performance indicators to measure the performance of grid-enhancing technologies in electricity transmission.

Europe’s energy transition is driving rapid growth in electricity demand and renewable generation, putting increasing pressure on transmission networks. While grid expansion remains key, making better use of existing infrastructure through innovative operational practices, digitalisation and grid-enhancing technologies is equally important, as smart solutions of transmission system operators (TSOs) can often deliver additional capacity faster and at a lower cost.

Why are transmission output performance indicators needed?

EU legislation already requires national regulators to monitor the development of smart electricity grids. To ensure smart grid solutions deliver benefits, regulators need ways to assess their real-world performance. 

The June 2025 Copenhagen Infrastructure Forum invited ACER, together with the European Network of Transmission System Operators for Electricity (ENTSO-E) and other stakeholders, to develop a common approach for assessing the performance of smart-grid solutions at transmission level.

In parallel, the Council of European Energy Regulators (CEER) publishes today its report on indicators to measure performance at distribution level.

Assessing transmission smart grid performance

Transmission smart grid infrastructure can be assessed using two types of indicators:

• input, which describe what has been implemented; and
• output, which monitor what has been achieved.

ACER found that few EU countries currently systematically measure how grid-enhancing technologies perform in practice, making it difficult to assess their effectiveness. This ACER paper addresses this gap. It builds a foundation for more consistent and comparable assessments of TSO performance across Europe.

What does ACER recommend?

ACER proposes three output indicators for regulators to assess whether grid-enhancing technologies in transmission grids deliver improvements and cost benefits:

• performance of existing transmission assets in real-time system operations,
• performance of operational security; and
• grid expansion performance.

These performance indicators address grid capacity gains, operational-security cost reductions and cost-efficient alternatives to conventional grid expansion. By capturing their actual performance, these output indicators help ensure that innovative approaches truly unlock grid capacity and reduce system costs. 

Beyond the three proposed output indicators, the paper also highlights complementary areas of monitoring that can enhance regulatory insight.

• ACER recommendation for national regulators: Incorporate the proposed indicators as a common framework for monitoring smart-grid performance at transmission level, allowing a two- to three-year transition period for data collection, process setup and methodological refinement.
• ACER recommendation for transmission system operators: Develop complementary input indicators reflecting the availability of tools that influence the proposed output indicators, with ENTSO-E providing guidance and reference mappings to ensure consistency across the EU.

What are the next steps?

Implementation should follow a phased, learning-oriented approach, starting with national testing of the indicators. A two- to three-year transition period will allow regulators to adjust them where needed as they are further developed and implemented.

Over time, the accumulated data and shared experience can support more systematic assessment of grid performance and innovation across Europe.