Today, ACER publishes its report on distribution system operator (DSO) investments and revenue setting. 

The report: 

• finds a major upscaling in electricity distribution grid investment trends across Europe;
• identifies some factors that may hinder efficient investments; 
• reviews the DSO landscape in Europe; 
• explores ways to address the challenges facing DSOs;
• proposes a set of 10 recommendations to optimise the ramp-up of distribution grid investment and improve services to grid user.

What are the main findings?

To accelerate decarbonisation, significantly more grid capacity is needed for electrification and renewables’ growth. This is driving a visible rise in electricity distribution grid investments across Europe. In 2024, annual distribution grid investments increased by over 50% to €35.3 billion (compared to €23.5 billion in 2021). Distribution grid investment is projected to approach €47 billion in 2027.

Beyond the investment challenge, DSOs face expanded roles under EU legislation. They must be active system operators (e.g. managing the system, utilising flexibility services, optimising electricity flows on the grid), market facilitators, data hubs, and innovation drivers – responsibilities that require new tools, specialised skills, and stronger coordination. 

Europe needs DSOs who provide high quality distribution services. As the system evolves, regulatory frameworks must adapt alongside it. 

This ACER report highlights several elements that might hinder efficient investments:

• Size matters. DSOs must be equipped to deal with evolving responsibilities for grid planning, flexibility solutions, grids’ digitalisation and resilience, to ensure all customers have equal access to high-quality and cost-efficient distribution services. Robust system planning and efficient regulatory scrutiny should not be compromised by fragmented and uncoordinated network development. 
• DSOs should adopt the most efficient solutions for network development – whether grid-based or non-grid (e.g. flexibility). The regulatory focus must expand beyond cost-cutting and maximise the benefits for society. Reducing capital expenditure (CAPEX) bias, still present in several countries, is key for improving regulatory regimes. 
• Rigid expenditure caps should not hinder nor distort key investments needed for the clean energy transition. 
• Distribution grid use and planned development should be more transparent. DSOs should strive to publish their mid-term cost trajectories and monitor grid utilisation to improve planning and operations.

ACER’s report offers 10 recommendations for legislators, regulators and system operators to optimise the ramp-up of distribution grid investment and improve services to grid users. These aim to ensure adequate competences, proper transparency and unlock efficient investments. National regulatory authorities should consider these recommendations when setting or approving their distribution revenue methodologies.

What are the next steps?

ACER will continue to:

• facilitate best-practice sharing among national regulatory authorities; and
• engage with stakeholders to gather insights.

In 2027, ACER will publish the next edition of its report on network tariff practices. ACER’s next report on revenue setting practices will be in 2028.

Europe has an EU-wide framework (called 'REMIT') to detect and deter market manipulation and abuse in wholesale energy markets. The Regulation was revised in 2024 to keep pace with evolving market dynamics. To make the framework fully operational, REMIT secondary legislation has also been updated with a recast REMIT Implementing Regulation and a new Delegated Regulation, both entering into force on 29 April 2026 (i.e. 20 days after their publication today in the Official Journal).

This reinforced REMIT framework enhances transparency and trust in the integrity of Europe’s energy markets. To support understanding and compliance with the new obligations, ACER has published two open letters (one on the recast Implementing Regulation and the other on the new Delegated Regulation).

In the coming weeks, ACER will also seek stakeholder input, via a public consultation, on a new guideline to help REMIT data reporting parties comply with their new obligations.

Key changes

1. The recast Implementing Regulation sets out updated rules for reporting energy market data to ACER, directly affecting all reporting parties (e.g. market participants, organised market places, registered reporting mechanisms and others). It aims to reduce reporting burdens while enabling more effective market monitoring and detection of potential abuses.

ACER’s open letter explains what has changed, focusing on the provisions that will enter into force first and on how to ensure compliance with the new act. It covers:

• new ‘exposure reporting’;
• new reporting timelines; and
• new obligations for organised marketplaces.

See also ACER’s evaluation of responses to the recent public consultation on the usefulness of ISO standards for exposure reporting.

2. The new Delegated Regulation introduces authorisation and supervision processes (including withdrawal and orderly substitution) for: 

• Registered reporting mechanisms (RRMs): Entities authorised to report energy data to ACER, either on their own behalf or on behalf of companies.
• Inside information platforms (IIPs): Online platforms where companies publicly disclose inside information (like power outages or capacity issues) so that all market participants can access it at the same time. IIPs are also officially authorised to report this information to ACER on behalf of companies.

ACER’s open letter on the Delegated Regulation explains: 

• the transitional period and the status of registered RRMs and IIPs during this period;
• the authorisation of new and registered RRMs and IIPs, including the requirement to be established in the EU; and
• key changes for ‘clients’ of RRMs and IIPs (e.g. market participants submitting or accessing energy data) under the new authorisation regime.

Together, these two acts aim to improve standardised data reporting, strengthen the supervision of REMIT data reporting entities and help ensure transparency and integrity in EU wholesale energy markets. 

Why does this matter?

The updated REMIT framework helps ensure that energy markets operate fairly, preventing market manipulation and insider trading, and ensuring important information is shared so that all market players compete on an equal footing. 

What’s next?

• ACER public consultation on a new guideline on REMIT transaction reporting to reflect evolving obligations under the revised framework (16 April - 12 June 2026).
• ACER and European Commission webinar: New REMIT implementing rules for energy market integrity and transparency (23 April 2026).
• ACER and European Commission annual REMIT workshop (11 June 2026).
• ACER consultations with targeted stakeholders on guidance documents for data reporting (including on the revised electronic formats). The revision process will be gradual, in line with the phased entry into force of new obligations, and will involve stakeholder consultation.

Today, ACER releases its report on the Latvian gas transmission tariffs, evaluating 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 methodology?

The Latvian regulator proposes to:

• Apply a uniform entry tariff of 142.77 EUR/MWh at all entry points within the Finnish-Estonian-Latvian (FinEstLat) market area, while removing tariffs at interconnection points within the area. 
• Apply a reference price methodology to set tariffs for domestic exit points and for renewable and low-carbon gases’ injection points.
• Grant full tariff discounts (i.e. zero tariffs) for entry points from and exit points to storage facilities.
• Set the exit tariff to Lithuania using the same FinEstLat entry tariff (142.77 EUR/MWh).
• Replace the current commodity-based tariffs (linked to the volume of transported gas) at domestic exit points with new capacity-based tariffs (charged for contracted network capacity).

What are the key findings? 

ACER concludes that: 

• The consultation document does not provide all required information, including on the:
  • comparison with the capacity-weighted distance methodology;
  • impact of the FinEstLat tariff structure on cross-subsidisation; and 
  • method used to forecast contracted capacity. 
• The proposed methodology complies with EU requirements on non-discrimination and volume risk. 
• However, it does not comply with the requirements on cost-reflectivity, cross-subsidisation and cross-border trade.

What does ACER recommend? 

ACER recommends that the Latvian energy regulator, when adopting its final decision:

• Follow ACER’s previous guidance (2023) on the FinEstLat market merger, monitoring how changes in gas flows could affect cross-subsidisation between networks.
• Switch to a capacity-based tariff system, allowing for a transitional period (if needed).
• Improve transparency by publishing the capacity-weighted distance components used in the cost allocation assessment.
• Compare capacity forecasts with those of neighbouring regulators and explain any differences found at the interconnection point with Lithuania.

Next steps

The Latvian regulator needs to adopt its final decision in time to publish the gas transmission tariffs by 6 June 2026.

See all ACER reports on national tariff consultation documents.

On 25 March 2026, ACER received a proposal from the European Network of Transmission System Operators for Electricity (ENTSO-E) to amend the methodology for the regional sizing of reserve capacity. 

What is the methodology about?

Balancing resources are necessary to manage differences between electricity supply and demand, keeping the grid stable in real time. To maintain this balance, transmission system operators (TSOs) determine the volume of reserve capacity needed at national level. 

At regional level, the methodology for the regional sizing of reserve capacity allows regional coordination centres (RCCs) to assess reserve needs across countries, taking into account volumes shared between TSOs through bilateral agreements. This coordination helps reduce procurement costs and ensure a more efficient distribution of reserves across Europe.

Based on their assessment, RCCs provide TSOs with recommendations on how to optimise reserve capacity volumes, thereby leveraging the flexibility of the EU electricity system.

Why amend the methodology?

As requested by ACER in 2023, ENTSO-E proposes to:

• determine the appropriate time span of historical data that RCCs should use to assess the minimum volume of reserves needed for the following year, ensuring the data used reflects relevant system conditions;
• specify how much reserve capacity is needed to cover positive and negative imbalances for a defined percentage of time.

These changes will help RCCs size reserve capacity more efficiently, address TSOs’ operational risks and enhance the process’ transparency and coordination.

ENTSO-E also proposes a new 24-month implementation deadline for assessing the short-term availability of reserve capacity that TSOs have agreed to share, starting from the date each agreement is signed. This deadline concerns only newly established agreements and reflects the voluntary nature of the task (i.e. it applies only where sharing agreements between TSOs are in place).

What are the next steps? 

ACER will decide whether to amend the methodology by 25 June 2026.

Interested parties are encouraged to submit comments or questions to ACER-ELE-2026-002@acer.europa.eu by 30 April 2026.

ACER has published its Recommendation to the European Commission on measures to speed up the effective implementation of EU electricity market rules. 

ACER’s monitoring found that major delays in implementing these rules hinder the proper functioning of Europe’s electricity system, resulting in economic costs for market participants and consumers.

Background

The EU electricity market is grounded in a comprehensive legal and regulatory framework. This includes EU-wide network codes and guidelines and the adoption of detailed rules (e.g. terms and conditions or methodologies (TCMs)), designed to ensure that the market operates efficiently. 

These rules set out key responsibilities for transmission system operators (TSOs), nominated electricity market operators (NEMOs), the European Network of Transmission System Operators for Electricity (ENTSO-E) and regional coordination centres (RCCs). 

Why an ACER Recommendation to the European Commission?

ACER’s (2024) monitoring found major delays in implementing the TCMs both at EU and regional level, affecting key areas such as electricity balancing, system operation and forward capacity. Delays in some TCMs had a domino effect, as they stalled progress of other TCMs.

This ACER Recommendation responds to the European Commission’s (2024) request for advice on how to strengthen the regulatory framework to reduce delays, with a focus on enforcement, governance and incentives.

What are ACER’s findings and recommendations? 

ACER’s Recommendation identifies challenges in three main areas:

• Implementation timelines: deadlines are often unclear or lack sufficient justification, making it difficult to track progress.
• Non-compliance: the decision-making process for addressing non-compliance by ENTSO-E and RCCs has room for improvement.
• Collective non-compliance: while the enforcement of individual obligations of TSOs and NEMOs poses no problem, current enforcement processes could fall short when tackling delayed implementation or failure to comply in cases where, across Union obligations, all TSOs or all NEMOs are tasked with jointly carrying out an obligation and collectively fail.

ACER recommends that the European Commission strengthen the regulatory framework by:

• Improving implementation and monitoring, introducing clearer deadlines and reporting requirements to reduce delays.
• Strengthening the enforcement framework in the ACER Regulation to ensure non-compliance by ENTSO-E and RCCs is addressed consistently and effectively.
• Assessing how to further improve enforcement for collective obligations (i.e. all TSOs and all NEMOs obligations).