On 27 March 2025, ACER received the transmission system operators’ (TSOs’) proposal to amend the harmonised allocation rules (HAR) for long-term electricity transmission rights.
The harmonised allocation rules apply to all long-term transmission rights allocations conducted within the European Union, specifying criteria for their auctioning (including use and curtailment of long-term transmission rights, eligibility criteria, etc.).
The TSOs’ proposal included various updates related to arrangements with market participants, reflecting upcoming market changes (e.g. introduction of 15-minute market time unit in the day-ahead electricity market) and recent incidents (e.g. single day-ahead market decoupling in June 2024).
To take an informed decision, ACER consulted stakeholders during Spring 2025.
ACER approves the TSOs' proposal, while adding some clarifications and proposing further reviews on the:
ACER agreed with TSOs to tackle improvements to the collateral requirements in long-term flow-based auctions separately.
TSOs and regulatory authorities should now review nomination rules and multiple NEMOs' arrangements to reflect the latest updates introduced by ACER.
Ahead of the European Commission’s Grids Package proposals (expected in Q4 2025), ACER sets out its recommendations for revising the current legal framework for grids.
Europe’s power grids need to be upgraded, expanded and optimised to connect more planned renewables and thus speed up a cost-efficient clean energy transition.
The European Commission estimated that investment needs for electricity grids will amount to €730 billion for distribution and €477 billion for transmission by 2040.
The European Commission is developing a Grids Package to improve and simplify the current legal framework. This includes the revision and simplification of the 2022 Trans-European Energy Networks Regulation (TEN-E Regulation), a key framework for European energy infrastructure development.
ACER's recommendations address network development aspects (rather than permitting or financing) to improve the efficiency of the EU network planning process and support a cost-effective energy transition. ACER’s focus is on key key areas of network planning and assessment, including:
ACER’s proposals aim to streamline procedures and accelerate the development of key energy infrastructure while reinforcing transparency, regulatory oversight and network planning governance across the EU.
ACER’s recommendations are grouped into two categories: measures aimed at strengthening the TEN-E process to address existing challenges, and those aimed at simplifying the process.
ACER proposes practical measures to simplify the Ten-Year Network Development Plans (TYNDPs), streamline the selection and monitoring of Projects of Common Interest (PCIs) and recognise the value of alternative solutions, such as non-wire options, to increase electricity grid capacity. ACER recommends to:
While some of ACER’s recommendations require amendments to the current legal framework, others could be achieved through better implementation of the existing regulatory framework.
ACER releases today an Opinion assessing whether the European transmission system operators (TSOs) followed the EU legal and regulatory framework when performing their bidding zone review study published on 28 April 2025.
Currently, most bidding zones in the EU are defined by national borders. But, under EU law, bidding zones must be formed 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.
In the review process, ACER role was to set the methodology and identify alternative bidding zone configurations for TSOs to consider in their review.
The TSOs’ report, which assesses 14 bidding zones configurations across Central and Northern Europe, is intended to help EU Member States decide whether to amend or keep the current bidding zones.
This ACER’s Opinion, addressed to the Council of the EU, assesses whether the TSOs’ study followed the agreed bidding zone review methodology and evaluates the impact of any deviations. It is not intended as a recommendation for Member States’ decisions.
ACER finds the study broadly aligns with the EU framework but significantly underestimates the benefits of re-shaping Europe’s electricity bidding zones. ACER identifies two main shortcomings:
ACER acknowledges the significant work by TSOs and other stakeholders in the study and the overall positive collaboration. The ACER Opinion also draws some recommendations to ensure a more effective and efficient process going forward.
Following the publication of the TSOs’ report (28 April 2025) Member States have six months to decide whether to amend the current 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.
The Director manages the EU Agency. The Board of Regulators is one of the Agency’s governing bodies. It represents the national energy regulatory authorities in ACER.
The Board of Regulator appointments were made, by consensus, at the 134th meeting of the ACER Board of Regulators today in Copenhagen. Ms Wargon and Mr Niculescu succeed Ms Clara Poletti (Italy) and Mr Rafal Gawin (Poland), the outgoing Chair and Vice Chair respectively.
At national level, Ms Wargon is Chair of the ‘Commission de Régulation de l’Énergie (CRE)’, the French energy regulatory authority, since August 2022. Mr Niculescu is President of the ‘Autoritatea Nationala de Reglementare in domeniul Energiei (ANRE), the Romanian energy regulatory authority, since April 2023.
The ACER term of office of the new Chair and Vice Chair takes effect immediately, from 17 September 2025, for a two-and-a-half year mandate (which is renewable).
The Chair and Vice-Chair member shall serve for a full term (2.5 years) or until the end of his/her membership of the Board of Regulators (i.e. if their term of office at national level ceases), whichever is earlier.
Mr Volker Zuleger was appointed Director ad interim of ACER, following a decision by the Agency’s Administrative Board on 12 September. He takes over as interim Director on 16 October 2025, ensuring the continuity of the service and the proper running of the Agency. He succeeds Mr Christian Zinglersen, who vacates the ACER Director post on 15 October to take up a new position elsewhere.
Mr Zuleger is currently Head of ACER’s Coordination, Operations and Legal (COL) Department, having worked for the Agency in different roles for 14 years.
The next step is the recruitment of the new ACER Director. This selection process will follow an open and transparent procedure launched by the European Commission.
ACER congratulates Volker, Emmanuelle and George and pays tribute to the dedicated service of Christian, Clara and Rafal in their respective roles.
For more on the ACER governance and different roles, see the Agency's organisation and bodies.
On 4 August 2025, ACER received two proposals from all nominated electricity market operators (NEMOs) to amend the harmonised maximum and minimum clearing price (HMMCP) methodologies for the European day-ahead and intraday markets, respectively.
Established under the Capacity Allocation and Congestion Management (CACM) Regulation, the HMMCP methodologies describe the automatic price adjustment mechanisms and how they may be triggered in cases of exceptionally high or low prices in Europe’s electricity day-ahead and intraday markets. They also define the maximum and minimum price limits (the so called ‘maximum and minimum clearing prices’) for the European day-ahead and intraday markets.
NEMOs propose to include an additional metric (based on market liquidity) among the conditions for triggering the automatic price adjustment mechanism. The purpose of such inclusion is to avoid the potential triggering of the automatic price adjustment mechanisms in cases of low liquidity in the European day-ahead and intraday markets.
ACER expects to decide on the methodologies by February 2026.
Interested parties are encouraged to submit comments or questions to ACER-ELE-2025-008@acer.europa.eu by 31 October 2025.
Update of 5 February 2026: With its Decisions 02/2026 and 03/2026, ACER approved the proposal.
Today, ACER publishes its Opinion on the updated manual of procedures for the European Network of Transmission System Operators for Electricity (ENTSO-E) Transparency Platform, submitted on 8 July 2025.
The ENTSO-E Transparency Platform is a key tool for collecting and centralising electricity data at the European level. It provides open access to information on electricity generation, transmission and consumption, supporting all market participants, including generators, retailers and traders.
In line with the Transparency Regulation, ENTSO-E must maintain and update a manual of procedures for the Transparency Platform, defining the data formats, communication standards, technical and operational requirements for data providers, as well as production type classifications. The manual must be developed through stakeholder consultation and submitted to ACER for an opinion before any updates are published. To date, ACER has issued four Opinions on ENTSO-E’s manual.
ACER finds that the updated manual aligns with the objectives of the Transparency Regulation and related EU legislation. In its Opinion, ACER:
ACER recommends further improvements to the manual, including:
ENTSO-E should take ACER’s recommendations into account and proceed with publishing the final updated manual of procedures.
Today, ACER publishes its 2025 Monitoring Report on electricity cross-zonal capacities and congestion management.
ACER Director, Christian Zinglersen, is in Copenhagen today to present key insights from the ACER report at the Council’s informal meeting of energy ministers under the Danish presidency.
The 2019 Clean Energy Package introduced a legal requirement on EU electricity transmission system operators (TSOs) to make at least 70% of their physical transmission capacity available for cross-zonal trade (by the end of 2025 at the latest) on all lines of cross-zonal relevance. This ensures that enough transmission capacity is allocated for cross-zonal trade with neighbours and mitigates discrimination against cross-zonal trade in favour of internal trade.
This ACER report highlights the importance of implementing the ‘70% rule’ to facilitate more cross-zonal electricity trade. Increasing the level of electricity trade between EU Member States enhances the resilience of the power system, optimises available resources and facilitates the efficient integration of renewable energy.
This ACER report underlines the importance of cross-zonal trade as a key source of power system flexibility, helping to shield consumers from price volatility and support the growth of renewables. ACER recommends:
Explore ACER’s interactive dashboard for data on cross-zonal electricity trade, congestion management costs and progress in meeting the 70% capacity rule by region.
The Regulation on Wholesale Energy Market Integrity and Transparency (REMIT) is the EU framework that protects consumers and businesses from energy market manipulation and insider trading.
Under REMIT, all market participants must register with the national regulatory authority in the country where they operate. Each regulator is responsible for establishing and maintaining a national register of market participants.
At EU level, ACER manages the European register of market participants, which is publicly available through the Centralised European Register of Energy Market Participants (CEREMP) platform and collects Member States’ national registers.
To ensure consistent data collection across the EU, ACER established a common registration format in 2012.
To keep up with evolving regulatory and technical requirements (including the 2024 revision of REMIT), ACER plans to update both the registration format and the CEREMP platform.
To inform its decision-making, ACER will seek stakeholders’ feedback on possible amendments through a public consultation from 1 to 29 October 2025.
