ACER releases two reports assessing whether the proposed reference price methodologies for the Croatian and Finnish natural gas transmission tariffs comply with the EU Network Code on Harmonised Transmission Tariff Structures.

The reports are addressed to:

• the Croatian national regulatory authority (NRA), Hrvatska energetska regulatorna agencija (HERA); and
• the Finnish natural gas transmission system operator (TSO), Gasgrid Finland Oy (Gasgrid).

ACER finds that Croatia’s proposal makes only minor adjustments to the previous well-functioning methodology (last updated in 2019), while Finland’s proposal retains its existing approach (2020) without addressing some of ACER’s earlier recommendations.

What is proposed?

Croatia proposes to:

• Keep the current postage stamp reference price methodology, with a 60/40% split between entry and exit points.
• Phase out the current tariff discount at the Krk LNG terminal entry point to the transmission system.
• Continue recovering all transmission revenues through capacity-based tariffs.
• Pre-set tariffs for a five-year period, with different tariff levels each year.

Finland proposes to:

• Keep the current postage stamp reference price methodology at domestic exit points.
• Remain in the Finnish-Estonian-Latvian (FinEstLat) market area, applying common entry tariffs and zero tariffs at interconnection points within the area.
• Establish a commodity-based connection capacity charge to recover costs fairly from users that consume gas only during peak periods. 
• Maintain the flow-based charge.
• Apply two non-transmission tariffs: a datahub charge and the Balticconnector underutilisation fee (charged when network users cut back their planned gas flows at short notice, beyond an allowed limit, on days of congestion).

What are ACER’s key findings and recommendations? 

Croatia 

After analysing the consultation document, ACER concludes that:

• The proposed methodology meets EU requirements on transparency, avoidance of cross-subsidisation, non-discrimination, volume risk and prevention of cross-border trade distortions.
• Compliance with the requirements on cost-reflectivity cannot be fully assessed, as it is unclear how the applied economic efficiency justification parameter affects the cost-reflectivity of the allowed revenue.
• The tariff methodologies for non-transmission services (the connection service and the 24 proposed non-standard services) lack sufficient details.

ACER recommends the Croatian NRA to:

• Ensure that the economic efficiency justification parameter does not compromise the principle of cost-reflectivity.
• Clarify how non-yearly bookings are handled in tariff setting.
• Align the tariff period with the Network Code’s requirements.

Finland

After analysing the consultation document, ACER concludes that: 

• The proposed methodology meets EU requirements on non-discrimination, volume risk and prevention of cross-border trade distortions.
• It partially meets the transparency requirements.
• Compliance with the requirements on cost-reflectivity and avoidance of cross-subsidisation cannot be fully assessed, mainly due to a lack of clarity on the effects of the market merger.
• The proposed connection capacity charge does not meet commodity charge criteria due to multiple factors, including its partial application to non-system user entities (e.g. distribution operators and their end-users).

ACER recommends the Finnish TSO to:

• Reconsider the new connection capacity charge to ensure it meets commodity charge criteria.
• Categorise the Balticconnector underutilisation fee as a balancing service, since it falls within the scope of the Network Code on Gas Balancing.

What are the next steps?

ACER encourages the Croatian NRA and the Finnish TSO to take these recommendations into account before adopting the final tariff methodologies.

See all ACER reports on national tariff consultation documents. 

ACER publishes today its first Recommendation on inter-temporal cost allocation mechanisms for financing hydrogen infrastructure. To ensure the recommendation is well-informed, ACER conducted a public consultation on the topic in spring 2025. 

What is inter-temporal cost allocation and why an ACER recommendation?

The EU aims to build a cost-effective hydrogen network to meet its climate goals. However, high infrastructure costs and demand uncertainty pose significant investment challenges, especially in the early stages of market development.

To address this issue, the EU Hydrogen and Decarbonised Gases Regulation (2024) grants Member States the authority to allow hydrogen network operators to recover infrastructure costs gradually over time through inter-temporal cost allocation mechanisms. These aim to ensure a fair and balanced distribution of costs between early and future consumers, ensuring that the former are not disproportionately burdened.

The regulation also assigns new hydrogen-related tasks to ACER, including issuing a recommendation to guide the development and implementation of inter-temporal cost allocation mechanisms. ACER’s Recommendation provides practical advice to support the rollout of hydrogen networks and ensure fair cost-sharing over the long term. 

What does ACER recommend? 

ACER’s Recommendation identifies key investment risks in hydrogen infrastructure and suggests ways to address them. It offers high-level guidance on designing fair and effective inter-temporal cost allocation mechanisms to support the development of the hydrogen market. ACER also highlights the need for Member States to promptly establish clear hydrogen regulatory frameworks and develop flexible national rules to accommodate the future EU-wide hydrogen network codes.

Given the early stage of the hydrogen market and the lack of established best practices, ACER does not yet propose a single, standardised EU-wide approach. Instead, it calls for:

• Regulatory authorities to:
  • ensure that inter-temporal cost allocation mechanisms and national market rules are developed in a coordinated manner;
  • strengthen cross-border coordination to avoid market fragmentation in the initial stage of the hydrogen market; and
  • establish clear and robust mechanisms that guarantee full cost recovery and fair cost distribution over time to support market growth.
• Network operators and planning bodies to:
  • ensure hydrogen network development is based on transparent, data-driven and realistic assumptions.

What are the next steps? 

ACER will review and update its Recommendation at least every two years, incorporating more refined guidance as the market evolves. The next publication is planned for 2027.

Today, ACER publishes its fifth report on cross-border cost allocation (CBCA) decisions for electricity and gas infrastructure projects.

Covering 50 decisions made between 2014 and 2024, the report provides insights into how these decisions, issued by national regulators, determine the cost distribution of major cross-border projects and support project development.

How cross-border cost allocation works

Cross-border cost allocation is a mechanism designed to fairly distribute the investment costs of projects of common interest (PCIs) and projects of mutual interest (PMIs) among the countries involved. It aims to support project implementation, especially in cases where some countries would otherwise bear significantly higher costs than the benefits the project provides.

Project promoters submit investment requests to national regulatory authorities, who review them and issue CBCA decisions to determine how project costs should be shared among involved countries. This cost-sharing arrangement is required for projects to receive financial support through the Connecting Europe Facility (CEF), a major funding programme that supports the development of strategic infrastructure across Europe. 

ACER monitors all submitted investment requests and decisions taken by national regulators and regularly reports on emerging trends.  

What trends did ACER monitoring find? 

ACER’s report shows:

• Fewer decisions overall: The number of CBCA decisions fell by around 65% in the second half of the monitoring period (2019-2024). This reflects a drop in the number of PCIs included in the EU project lists, partly due to completion of major energy infrastructure projects, but also the phase-out of natural gas and Brexit, which made several projects ineligible for inclusion in the PCI lists.
• Costs stay national in most cases: Member States usually agree to cover their own costs, as each one benefits sufficiently from the project.
• Connecting Europe Facility (CEF) is the key driver: Access to grants, not the need to share costs, is the main reason project promoters submit investment requests. 
• No CBCA decisions yet for hydrogen: The sector is still in an early stage of development, but with hydrogen projects becoming eligible for inclusion in the PCI and PMI lists since 2023, CBCA decisions are expected in the coming years.

ACER’s 2025 retail energy country sheets offer a concise overview of the national electricity and gas markets across EU Member States and Norway. For the first time, the country sheets cover both sectors, presenting: 

• market and competition metrics for electricity and gas; 
• consumer trends (including contract types, contract switching rates and bill breakdown); 
• progress towards enabling more flexible consumers (through smart meter roll-out, prosumer participation, deployment of electric vehicles and heat pumps, and biomethane production); and
• a high-level assessment highlighting each market’s strengths, weaknesses, opportunities and threats (SWOT analysis). 

ACER has also updated its retail pricing dashboard, which shows monthly changes in household energy prices across EU Member States and Norway from January 2019 to June 2025.

What are the main findings in retail markets?

Electricity market

• Smart meters, a key enabler for demand-side flexibility, are largely in place across the EU, but roll-out levels vary among EU Member States and Norway. In half of EU Member States, deployment has reached 80%, while in 7, deployment remains below 20% (or no data was provided). 
• Although 2024 saw an increased number of hours with low wholesale electricity prices (below €5/MWh), fixed price and/or regulated contracts still dominate in 15 Member States at the household level. This widespread uptake limits consumers’ exposure to real-time price signals, preventing cost savings and hindering more innovative and flexible contracts. The limited adoption of dynamic-price contracts suggests that demand-side flexibility potential remains untapped.
• In 21 Member States, prosumers account for between 1% and 10% of households. The highest shares are observed in Belgium (22%) and the Netherlands (30%). 

Gas market

• 82% of residential energy consumption is used for space and water heating, underlining the importance of energy efficiency and building renovation strategies to support decarbonisation.
• A decline in gas demand has been recorded in 21 Member States since 2022, while biomethane production remains relatively low.

Market structure

• Both electricity and gas retail markets show moderate to high concentration across the EU, meaning a small number of suppliers hold a large share of the national market. 
• 20 Member States either recorded low switching rates (below 10%) or did not provide data, indicating limited competition or low consumer engagement.

The country sheets complement ACER’s retail Monitoring Report (coming in November).

Retail prices: Latest trends from ACER’s dashboard 

ACER’s retail pricing dashboard highlights the main trends in household electricity and gas prices. 

• Electricity prices across Europe stabilised by June 2025, ending the decline observed since early spring. Spain and Portugal recorded the sharpest monthly rises (+7% and +6%, respectively), followed by more moderate increases in Greece, the Netherlands, Italy and Austria. In contrast, prices declined in Norway (-7%), Estonia (-3%), and in Belgium, Latvia, Sweden and Lithuania (-2%). Most other countries recorded no change. On an annual basis, EU household electricity prices rose by approximately 3%.

• Retail gas prices also remained largely stable, with minor monthly changes: Belgium and Portugal registered small increases (+1%), while Italy recorded the largest decrease (-4%), followed by France and Latvia (-2%), and the Netherlands, Estonia and Austria (-1%). While retail gas prices remained unchanged month-on-month in most Member States, retail offers were approximately 7% higher than those available during the same period last year. 

What are the main trends in wholesale gas markets? Prices remained elevated year-on-year but showed little monthly change, despite volatility driven by global trade and security shocks. More information is available in ACER’s monitoring report on key developments in gas wholesale markets report, published today.

Published today, ACER’s latest report on key developments in European gas wholesale markets (Q2 2025) examines key trends in prices, supply and storage during the early months of the gas summer season. The analysis supports policy discussions on enhancing secure and competitively priced gas in Europe.

What trends did ACER monitoring find? 

• Gas wholesale prices and volatility: Average wholesale gas prices fell by over 20% compared to Q1 2025, following a high-price winter. Price volatility eased, but remained relatively high, while regional price differences widened.
• LNG imports: Liquefied natural gas (LNG) imports rose by more than a third year-on-year, supported by competitive hub prices, slack demand in Asia and expanded US liquefaction capacity.
• Pipeline imports: No major changes were observed except for Russian supply to the EU, which dropped by 45% year-on-year following the expiry of transit contracts via Ukraine. Deliveries now reach the EU only through the TurkStream pipeline.
• Gas storage: Gas injections increased by 75 TWh year-on-year, helping to reduce the gap in storage levels compared to previous years. This follows a relatively tight end-of-winter, when stocks were lower than in 2023 and 2024. 

Looking ahead

If current LNG inflows and storage injection levels continue, Europe is likely to enter winter with healthy reserves. Still, risks remain: extreme weather, disruptions to major supply sources, or geopolitical instability could alter the trajectory. On the supply side, the expected expansion of global LNG production in late 2025 and 2026 may help ease pressure.

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 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.

As Europe moves away from Russian fossil fuels, liquified natural gas (LNG) is becoming an increasingly important flexible supply source. But with future gas demand uncertain, the EU faces a trade-off: securing higher LNG volumes to ensure stabler pricing, while maintaining the flexibility to avoid over-contracting in a changing market.

ACER’s 2025 Monitoring Report highlights:

• LNG’s share of the EU’s total gas supply rose from 23% in 2020 to around 40% in 2024.
• The EU remained the world’s largest LNG importer, with 112 bcm imported despite a 17% drop from 2023.
• The US supplied nearly 50% of EU LNG imports, while Russian LNG to EU increased by 22%, despite sanctions. 
• Over 550 EU spot LNG trades with delivery were reported to ACER, totalling 45.5 bcm – 55% of which were priced below 35 EUR/MWh.
• The EU purchased 30 bcm of LNG on the spot market, more than any other major importer.
• The EU faces up to 90 bcm of demand uncertainty between Fit for 55 and REPowerEU scenarios, which could lead to 30 bcm in additional LNG demand by 2030 (compared to 2024 levels) and prolonged reliance on the spot market.

ACER recommendations

To manage future gas demand uncertainty and price risks, key actions are needed from policymakers, network operators and market players:

• Accelerate decarbonisation efforts to reduce structural gas demand through faster deployment of renewables and improved energy efficiency.
• Secure additional LNG through flexible contracts to help reduce short-term exposure to price volatility.
• Improve coordination and effective data-sharing between Member States and the European Commission to enable better monitoring of decarbonisation progress and guide LNG procurement.

What are the next steps? 

Register for the ACER webinar on the evolving role of LNG in Europe (28 May 2025).

Read more.