This report on gas network use provides a comprehensive overview of capacity booking and usage trends in the EU, exploring how diversified supply, demand shifts and evolving capacity booking strategies are reshaping gas flows across the EU.

This monitoring report compares gas capacity use and booking data from 2021 to mid-2025 and analyses the main market shifts triggered by the energy crisis in 2022 (e.g. phase-out of Russian natural gas, increase in liquefied natural gas (LNG) imports, and lower gas demand). It also examines the impact of ending Russian gas transit via Ukraine as of 1 January 2025 on flow dynamics and capacity use across Southeast Europe.

What are the key findings? 

The EU’s integrated gas system has proven resilient to the energy crisis, reconfiguring its gas flows in response to changing supply and demand patterns. 

• Europe’s reliance on Russian gas pipeline imports has fallen from circa 40% to 6% of total imports since 2021.
• Since the end of 2021, gas flows have reversed direction at 40% of gas interconnection points across the EU, driven by the phasing out of Russian pipeline gas.
• Lower gas demand and increasing LNG’s supply reduced transit flows in some countries, leading to fewer capacity bookings and putting upward pressure on tariffs.
• Capacity bookings are adapting to new gas market conditions. Many long-term legacy contracts are expiring or have been terminated due to the Russian invasion of Ukraine. Instead shippers are now securing capacities on alternative routes through auctions underpinned by the EU-wide capacity allocation mechanism (CAM) network code.
• Lower pipeline congestion at EU level, but some supply bottlenecks persist. Infrastructure upgrades and lower gas demand have eased the peak congestion that affected Northwest Europe in 2022. Since 2024, high network use in Southeast Europe (including increased gas volumes to Ukraine in 2025 following the end of Russian gas transit), created significant congestion risks at several interconnection points in the region.

What are ACER’s recommendations?

• Transmission system operators (TSOs) should enhance transparency and coordination in gas capacity optimisation.
• National regulators should ensure a full and consistent application of the EU rules (CAM network code) without exceptions to maintain a transparent, predictable, and standardised capacity allocation process, fostering competition and integration of EU gas market.
• Future gas infrastructure investment by Member States should be targeted to solve persistent bottlenecks, align with the EU’s energy and climate goals and ensure security of supply. Regulators must ensure transparent and efficient distribution of congestion revenues to reduce and stabilise tariffs for European network users.

What are the next steps?

ACER will provide its next key developments in European gas wholesale markets report in early 2026. See the Q3 2025 monitoring report, also published this week.  

Published today, ACER’s latest report on key developments in European gas wholesale markets examines key trends in gas supply, demand and market prices during the final months of the gas summer season (July to September 2025). The analysis helps inform policies aimed at ensuring secure and competitively priced gas in the EU. 

What trends did ACER monitoring find? 

• Wholesale prices and volatility declined, marking one of the calmest periods for European gas markets in recent years. Higher gas imports, stable consumption and orderly storage filling contributed to this stability.
• Gas storage: Injections into underground storage exceeded levels of the previous two summers. European stocks reached 82% capacity, below levels at the start of the last three heating seasons, leaving EU markets more reliant on imports this winter.
• LNG imports: Liquefied natural gas (LNG) imports rose by 38% year-on-year amid high storage demand and lower Russian pipeline supply. Stable demand from other major buyers and rising global LNG production contributed to lower prices despite higher import volumes.
• EU gas market integration drove gas flows in the right direction to Central and Eastern Europe: As LNG’s share of supply grew, gas flows were redirected eastward to markets with limited or no direct LNG access, reflecting wholesale market signals (from lower- to higher-priced hubs).

Today, ACER initiates the review of its Decision 30/2020 on the electricity redispatching and countertrading cost sharing methodology for the Core capacity calculation region.  

What is a capacity calculation region?

A capacity calculation region is a set of electrically interdependent bidding zone borders, where capacity calculation, regional operational security, redispatching and countertrading costs sharing tasks are coordinated by that region’s transmission system operators (TSOs).

The Core capacity calculation region involves the TSOs and bidding zone borders of Austria, Belgium, Croatia, Czech Republic, France, Germany, Hungary, Luxembourg, the Netherlands, Poland, Romania, Slovakia and Slovenia. It is the biggest European region, involving 13 Member States, 16 TSOs and 19 bidding zone borders.

What is the methodology about? 

The cost sharing methodology allocates the costs from redispatching and countertrading remedial actions within a capacity calculation region. These actions are triggered to solve network congestions occurring within the region. 

Specifically, this methodology tracks how each action affects congested network elements and assigns the related costs to the responsible TSOs, based on the order of flow types (loop, internal, allocated and power-shifting transformer flows). Loop flows are charged first, however according to the Electricity Regulation, its portion below a given threshold is exempted.

Why amend the methodology?

On foot of the ACER Board of Appeal Decision of 31 July 2025, ACER is now revising its Decision 30/2020 and the methodology accordingly.

What are the next steps?

ACER aims to adopt its Decision by the end of January 2026.

On 26 September 2025, ACER received a proposal from the European Network of Transmission System Operators for Electricity (ENTSO-E) to amend the methodology for the regional procurement of balancing capacity.

What is the methodology about?

Transmission system operators (TSOs) must always keep the power system in balance. TSOs usually procure the balancing capacity needed at national level, but to lower procurement costs, they may opt for utilising available voluntary balancing bids from other countries (e.g. made available when local capacity exceeds national needs).  If transmission capacity is expected to be available across bidding zones during balancing, these bids can also be used to reduce balancing capacity needs. 

The methodology for the regional procurement of balancing capacity enables regional coordination centres (RCCs) to evaluate how voluntary balancing bids can be utilised effectively across borders. Following this evaluation, regional coordination centres provide TSOs with recommendations to reduce the volume of procured balancing capacity, hence utilising the flexibility of the EU electricity system. 

Why amend the methodology?

As requested by ACER, European TSOs propose to update the reliability parameters used by regional coordination centres to assess the availability of cross-zonal capacity and voluntary balancing bids. This is important as reliability parameters need to reflect the most relevant data, enabling TSOs to procure balancing capacity efficiently, and at the same time managing their operational risks. This change should foster a more transparent and coordinated process and improve the balancing of EU power system.

What are the next steps? 

ACER will decide by 5 January 2026.

Interested parties may submit comments or questions to ACER-ELE-2025-009@acer.europa.eu by 31 October 2025.