Today, ACER publishes its report on trends in the European gas wholesale markets during the gas winter season (October 2024 to March 2025). The report also explores gas storage dynamics over the winter and offers an outlook for summer 2025. 

What trends did ACER monitoring find? 

European gas markets came under more pressure this winter due to higher demand and lower supply.

• Wholesale prices increased by 50% compared to last winter, though regional price variations narrowed.
• Gas consumption increased year-on-year, driven by colder weather than in the past two winters and exceptionally low wind generation. 
• Despite increased demand and the halt of Russian gas flows via Ukraine, gas networks avoided congestion thanks to full storages at the start of winter, expanded LNG infrastructure, and gas consumption remaining structurally lower than pre-crisis levels.
• Storage levels ended winter at 34% capacity, in line with pre-2022 norms but well below 2023-2024 levels. Significant injections will be needed before next winter.
• LNG imports rose seasonally but stayed below early winter 2023 levels. Later in the season, with European gas wholesale prices exceeding Asian spot LNG prices and new US liquification coming online, EU LNG imports hit record monthly highs.

Looking ahead 

To meet summer 2025 gas needs and refill EU gas storage to 90% by next winter, ACER estimates that pipeline flows must remain high and LNG imports will need to increase by 20% compared to summer 2024. 

Today, ACER publishes its report on the Czech gas transmission tariffs directed at the Energetický regulační úřad/Energy Regulatory Office (ERO), the Czech national regulatory authority.

The report assesses whether the proposed reference price methodology complies with the requirements of the EU binding Network Code on Harmonised Transmission Tariff structures. 

What is the proposed tariff methodology about?

The regulator proposes to:

• Adopt a capacity weighted distance methodology as the reference price methodology.
• Adjust the entry-exit split from the current 9-91% to 15-85%. 
• Reduce the discount applied to entry and exit points of storage facilities from 100% to 80%.

What are the key findings? 

After analysing the consultation document, ACER concludes that:

• The proposed methodology largely complies with the requirements of the network code.
• Most required information is provided, with the exception of the calculation and components of the cost allocation assessment. 
• The proposed commodity-based charge generally aligns with Article 4(3) of the tariff network code (which sets the rules for commodity-based tariffs). 

What does ACER recommend? 

ACER recommends that the national regulatory authority (ERO), when adopting its final decision:

• Consults on any benchmarking adjustments, respecting the two-month consultation period set in the tariff network code. If this timeframe cannot be met, ACER recommends that ERO provides the longest possible consultation period, anticipating the opening and closing dates to stakeholders and ACER.
• Justifies the results of the cost allocation assessment, providing an explanation on how the outcomes vary when different assumptions are used. This should help identify the most suitable methodologies for the transmission network.
• Justifies the use of an alternative pricing mechanism for the flow-based charge at interconnection points. For this purpose, ERO should demonstrate that there is a significant risk of volatility in cross-system flows that could impact the cost reflectivity of the flow-based charge.

See all ACER reports on national tariff consultation documents.

Today, ACER releases its report on the Lithuanian gas transmission tariffs directed at the Valstybinė Energetikos Reguliavimo Taryba (VERT), the national regulatory authority (NRA) of Lithuania.

The report assesses the compliance of the proposed reference price methodology (RPM) with the requirements of the Network Code on Harmonised Transmission Tariff structures. 

What is the proposed methodology about?

The Lithuanian regulator proposes to:

• Apply a postage stamp reference price methodology with flexible entry-exit splits, complemented by a 100% discount at entry points for domestic biomethane producers.
• Align entry tariffs with those of the neighbouring FinEstLat (Finland, Estonia and Latvia) zone.
• Simplify the existing tariff structure by abandoning the previously applied system based on multiple asset cost splits and differentiated tariffs.
• Use a flow-based charge (commodity-based tariff) with a fixed tariff level for the entire regulatory period.
• Offer a conditional product with limited allocability (i.e. the product can only be used to ship gas to pre-defined system points) at entry and exit points with non-EU countries.

What are the key findings? 

After analysing the consultation document, ACER concludes that:

• The proposed methodology meets the requirements on transparency, non-discrimination, and volume risk.
• Compliance with the requirements on cost-reflectivity, avoidance of cross-subsidisation, and prevention of cross-border trade distortions cannot be fully assessed, due to several design elements of the methodology.
• While the criteria for setting the flow-based charge are met, further clarification is needed on how the charge will be adjusted and reconciled. 
• Simplifying the tariff structure has made the methodology more understandable for system users.

What does ACER recommend? 

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

• Provides a clear framework for the flow-based charge, preferably by recalculating its level annually.
• Ensures full compliance of non-EU entry and exit points with the network code. 
• Assesses regional networks and allocates their costs in a compliant way, in line with EU rules and ACER’s guidance.

See all ACER reports on national tariff consultation documents. 

Today, ACER releases its report on the German gas transmission tariffs directed at the Bundesnetzagentur für Elektrizität, Gas, Telekommunikation, Post und Eisenbahnen (BNetzA), the national regulatory authority (NRA) of Germany.

The report assesses the compliance of the proposed reference price methodology (RPM) with the requirements of the Network Code on Harmonised Transmission Tariff structures (NC TAR). 

What is the proposed RPM about?

The German NRA proposes to:

• Apply a postage stamp RPM with uniform entry and exit tariffs.
• Use conditional products with discounted tariffs.
• Use non-transmission services, including metering at exit points (for both end-users and distribution networks) and alternative nomination procedures for gas deliveries.

What are the key findings? 

After analysing the consultation document, ACER concludes that: 

• The RPM complies with the requirements of the network code on transparency, non-discrimination and volume risk.
• Due to insufficient information on regional networks, ACER could not assess the compliance of the proposed tariffs with the principles of cost-reflectivity, avoidance of cross-subsidisation and prevention of cross-border trade distortions. 
• While the criteria for setting metering charges are met, ACER could not assess whether the proposed tariff methodologies for alternative nomination procedures comply with NC TAR principles.

What does ACER recommend? 

ACER recommends that the NRA, when adopting its final decision:

• Assess regional networks and allocate their costs in a compliant way, in line with EU rules and ACER’s guidance.
• Provide more clarity on how discounted tariffs for conditional products are calculated.

See all ACER reports on national tariff consultation documents. 

ACER kicks off its 2025 Monitoring Report series with key insights into the EU energy markets, highlighting major developments in 2024, and examining the interplay between gas and electricity markets in the energy transition.

What are the key findings?

The report highlights progress towards Europe’s transition to clean energy, persistent challenges (such as high and volatile energy prices for European consumers and businesses), and how to address them. It sets out ACER’s recommendations on how Europe can unlock a clean, secure and competitive energy future.

• 2024 recorded the lowest energy prices since 2021, but with noticeable regional differences. Gas prices averaged 34 €/MWh and electricity averaged 81 €/MWh. The surge in negative and very low prices in 2023 intensified in 2024.
• Energy market prices remained volatile (but less extreme than during the crisis), driven by gas supply risks and renewables’ variability. Frequent swings in electricity prices (within a day) persist – on 70% of days, electricity price variations within the day reached 50€ or higher. Electricity price swings reveal a need for more short-term flexibility.
• Renewables grew significantly, accounting for 35% of power generation. Solar power confirmed its leading role in the energy transition whilst nuclear and hydro came back.
• Europe’s clean energy transition faces persistent challenges. Gas supply risks and unpredictable weather later in the year kept market prices volatile. In December, a ‘dunkelflaute’ episode in Germany sent electricity prices to nearly 1,000 €/MWh (far above the 81 €/MWh annual average). 
• Gas as a flexibility provider. Fossil fuels, especially gas and coal, remain essential for meeting peak electricity demand.

ACER’s recommendations to address these challenges:

For decarbonisation and global competitiveness, Europe must place renewed effort on further expanding EU energy market integration, enhancing energy efficiency, and driving power grid innovation:

• Target new transition cost drivers: Network costs are at risk of doubling by 2050. Enhancing grid capacity (rather than new build) is part of the solution. Better network tariffs and 'efficiency first' incentives to prevent stranded assets play an important role. Ensure capacity, flexibility, and renewables remain affordable while securing long-term supply.
• Harness energy efficiency and flexibility: Use demand response, electric vehicles (EVs), and batteries to balance supply and demand, cut price swings, and strengthen grid resilience, especially at peak times.
• Expand energy market integration: Support cross-border renewable use for flexibility and security. Strengthen interconnections to cut fossil fuel reliance and build trust in Europe’s energy markets.

Looking ahead 

In its 2025 Monitoring Report series, ACER will continue to pave the way for a clean, secure and competitive energy future by shedding light on:

• strengthened cross-border cooperation;
• energy transition monitoring; and
• efficient grid investment.

Upcoming reports:

• ACER's Monitoring Report on removing barriers to demand response (to be published here on 8 April).
• ACER’s report on EU electricity tariff practices (coming on 26 March).

Today, ACER releases its report on the Hungarian gas transmission tariffs directed at Magyar Energetikai és Közmű-szabályozási Hivatal (MEKH), the national regulatory authority (NRA) of Hungary.

The report assesses whether the proposed reference price methodology (RPM) complies with the requirements of the Network Code on Harmonised Transmission Tariff structures (NC TAR). 

What is the proposed RPM about?

The NRA proposes to:

• Apply a postage stamp RPM complemented by a 90% discount at entry points from storage and 100% discounts at exit points from storage. It also suggests applying a 50/50 entry-exit split but is open for adjustments within a 40/60 to 60/40 range subject to stakeholder feedback.
• Adopt an in-kind flow-based charge (commodity-based tariff). However, taking into consideration inputs received from stakeholders, MEKH already informed ACER about its intent to switch back to a monetary flow-based charge (already in place since 2021).
• Introduce two non-transmission services, respectively for gas odorisation and for connecting users to the network. 

What are the key findings? 

After analysing the consultation document, ACER concludes that: 

• The RPM largely complies with requirements set in Article 7 of the NC TAR. 
• ACER could not assess the compliance of the proposed flow-based charge, as the relevant NRA decision is only available in Hungarian. However, given MEKH’s intent to switch to a monetary flow-based charge, ACER referred to its 2021 analysis, assessing the compliance of the tariffs proposed at that time.
• The proposed non-transmission services also comply with EU rules. 

What does ACER recommend? 

ACER recommends that the NRA, when adopting its final decision:

• Ensure the compliance of the commodity-based tariffs with the NC TAR, particularly considering that the monetary flow-based charge will be applied instead of the in-kind one (e.g. stakeholders were consulted upon the latter, but not the former).
• Reconcile the proposed non-transmission services as required by Article 17(3) of the NC TAR.

See all ACER reports on national tariff consultation documents. 

Today, ACER releases its report on the Swedish gas transmission tariff directed at the Swedish National Regulatory Authority (NRA), Energimarknadsinspektionen (Ei), and Transmission System Operator, Swedegas.

The report assesses whether the proposed Reference Price Methodology (RPM) complies with the requirements of the Network Code on Harmonised Transmission Tariff structures (NC TAR). 

What are the key findings? 

After analysing the consultation document, ACER concludes that:

• Most of the required information is provided, however, the forecasted contracted capacity, tariff comparison between periods, and detailed information on some non-transmission services are missing. 

• The input parameters of the proposed RPM do not fulfil the transparency requirements of the NC TAR. As a result, ACER concludes that the proposed RPM is not fully compliant with the transparency principle.

• While the choice of the postage stamp methodology is well justified, limitations identified in the allowed revenue estimation and revenue reconciliation raise concerns about the cost reflectivity of the proposed tariff. Consequently, ACER cannot conclude that the proposed RPM complies with the cost-reflectivity principle. 

• The proposed RPM achieves a reasonable level of cross-subsidisation compared to the alternative capacity-weighted distance methodology while complying with the principles of non-discrimination, volume risk, and the prevention of distortions in cross-border trade. 

• The information provided on the three non-transmission services (fees for extra area consumption, capacity allocation for summer and winter periods, and capacity allocation for daily capacity products) is insufficient to assess the compliance with the NC TAR principles.

What does ACER recommend? 

ACER recommends that the NRA, when adopting its decision:

• Includes the missing elements and clarifies inconsistencies in the calculation of input parameters for the tariff-setting process, ensuring stakeholders fully understand the methodology. 

• Specifies the start of the regulatory period for the proposed RPM and the applicability of the consulted tariff.

• Provides the missing information on the three additional non-transmission services. 

ACER welcomes the steps taken by the NRA to realign the allowed revenue with Article 17 of Renewable Gas, Natural Gas and Hydrogen Regulation, ensuring it reflects the TSO’s actual costs, as long as they correspond to those of an efficient and structurally comparable network operator. 

Additionally, ACER appreciates that the TSO and NRA followed its recommendation in the 2024 tariff report and conducted another consultation on the applied methodology. 

See all ACER reports on the national tariff consultation documents.

Today, ACER releases its report on the Romanian gas transmission tariffs directed at the Autoritatea Naţională de Reglementare în domeniul Energiei (ANRE), the National Regulatory Authority (NRA) of Romania.

The report assesses whether the proposed reference price methodology (RPM) complies with the requirements of the Network Code on Harmonised Transmission Tariff structures (NC TAR). 

What are the key findings?

After analysing the NRA’s consultation document, ACER finds that, while most of the required information is available, the absence of important elements prevents a complete assessment of the proposed methodology’s compliance with the Network Code requirements. In particular:

• ANRE did not provide sufficient justification for choosing the proposed postage stamp methodology, making it difficult for stakeholders to evaluate its suitability.
• While the postage stamp methodology may be appropriate, ACER cannot determine its compliance with the NC TAR principles (e.g. cost-reflectivity, preventing cross-subsidisation, and avoiding cross-border trade distortions) without further clarification.
• While the transparency and volume risk criteria of the NC TAR are not directly addressed in the consultation document, ACER could still conclude that the proposed methodology meets these requirements. Additionally, ACER did not identify any discriminatory elements in the proposed RPM.
• Although the criteria for setting non-transmission charges are met, the non-transmission revenue is not included in the allowed revenue, contrary to Network Code requirements.
• Finally, the criteria for setting commodity charges align with NC TAR requirements.

What does ACER recommend?

ACER recommends that the NRA, when adopting its decision, further justify the choice of the proposed RPM by including the following elements:

• Further considerations on the system’s technical characteristics and flow dynamics, focusing on distance as a potential cost driver.
• The conclusions drawn from the comparison of the proposed RPM with the Capacity Weighted Distance (CWD) methodology.
• A detailed assessment of the proposed RPM against all requirements outlined in Article 7 of the NC TAR.

ACER also invites ANRE to clarify how costs associated with the inclusion of the “transit” pipeline (part of the Trans-Balkan pipeline infrastructure) in the national transmission system have been taken into account.

Access all ACER reports on national tariff consultation documents.

The EU’s Hydrogen and decarbonised gas market package (2024) aims to support the development of a competitive hydrogen market and the integration of renewable gases into Europe’s energy system. To achieve this, the package extends the role of ACER to include new hydrogen-related tasks.

One of these tasks, set out in the Regulation on hydrogen and decarbonised gas market, requires ACER to issue a recommendation on the methodologies for setting the inter-temporal cost allocation by 5 August 2025 and update it at least every two years. 

To inform the drafting of this recommendation, ACER will seek stakeholder input through a public consultation from 10 to 31 March 2025.

What is inter-temporal cost allocation?

Developing a European hydrogen market will require significant infrastructure investment to transport hydrogen from supply sites to end users. However, funding this infrastructure through traditional regulated tariffs (fees paid by network users) could result in extremely high fees for early users, making hydrogen less affordable and potentially discouraging further demand.

To address this issue, the Regulation on hydrogen and decarbonised gas market grants Member States the authority to allow hydrogen network operators to recover infrastructure costs over time through inter-temporal cost allocation mechanisms. These aim to ensure a fair distribution of costs between early and future hydrogen consumers, ensuring that the former are not disproportionately burdened.

ACER’s recommendation will provide guidance to Transmission System Operators (TSOs), Distribution System Operators (DSOs), hydrogen network operators, and National Regulatory Authorities (NRAs) on how to develop and implement these mechanisms effectively.