10th Three Seas Summit: From gas trap to clean power and connectivity

The Three Seas Initiative (3SI) is returning to Warsaw on April 28th to convene its tenth annual summit, with an opportunity to reshape energy security in Central and Eastern Europe. Analysis finds that Russian gas could be eliminated from 3SI countries with existing infrastructure. In contrast, the planned expansion of LNG terminals and pipelines clashes with decreasing gas demand, creating a risk of underutilised assets already by 2030. The anniversary 3SI summit should align around a full Russian gas phase-out and begin prioritising renewables, efficiency and flagship interconnection projects.

3SI represents the most prominent political partnership between Central and Eastern European countries (Estonia, Latvia, Lithuania, Poland, Czechia, Slovakia, Hungary, Slovenia, Croatia, Bulgaria, Romania, Austria and Greece), including Ukraine and Moldova as partner participants. Throughout its existence, the 3SI energy vector has been dominated by natural gas diversification projects, which are now outdated and unnecessary. 

Last year’s 3SI gathering in Vilnius recognised for the first time the importance of renewables and connectivity in providing prosperity for the region. The tenth anniversary summit should leverage the concurrent Polish EU Council Presidency that is prioritising energy security, to build on those advancements and begin preparing flagship clean power, efficiency, electrification and interconnection projects. These will not only support the key security objective of a 2027 phase-out of Russian gas, but also boost innovation and economic growth. 

Mixed progress on decoupling from Russia

Since last year’s Summit in Vilnius, several efforts have been made to reduce reliance on Russian energy imports. On 9th February 2025, Estonia, Latvia, and Lithuania achieved a major milestone by successfully integrating their grids with the Continental Europe Synchronous Area (CESA), strengthening their energy independence. Furthering these efforts, major advancements are being made in the development of the new power connector between Poland and Lithuania – Harmony Link. Russian pipeline gas flows through Ukraine ended on January 1st, 2025. Three Seas countries also saw some of the highest growth in solar power, with Hungary rising to the top of the EU leaderboard. The rise of clean power helped achieve gas demand reductions across the 3SI – from 8% in Poland, through 15-19% in Central Europe, to 28% in Lithuania, compared to pre-crisis levels (2022-2024 average compared to 2019-2021 average).

However, in stark contrast to this progress, Russian gas imports to the EU rose by 18% in 2024, with some major increases seen in 3SI countries: Czechia (+2 bcm), Poland (+0.6 bcm), Greece (+0.5 bcm). Both Russian LNG and pipeline imports continued to increase in the first months of 2025, even after gas flows through Ukraine ceased on 1st January 2025. This is despite countries like Czechia declaring an intention to end their dependence on Russian energy.

Three Seas without Russian gas

Being the most exposed to Russia’s aggression, 3SI countries have a strong incentive to decouple from Russian fossil fuels as quickly as possible. While concerns about the technical feasibility of this were raised in the past by landlocked Austria, Hungary and Slovakia, the three countries already have access to sufficient alternative supplies, largely due to EU-funded infrastructure upgrades over the past decade. In fact, non-Russian gas import capacities already exceed their demand, which helped them avoid disruptions when Ukrainian transit stopped in early 2025. Czechia, a 3SI member with the highest growth in Russian gas imports in 2024, is also capable of covering its gas demand without Russian supplies.

Gas reliance might be a costly mistake

The phase-out of Russian gas is made easier thanks to the declining gas demand across the region. Despite that, several countries continue to support the expansion of LNG import infrastructure. In total, the LNG import capacity across the 3SI is set to double by 2030 (from 25 bcm to 48 bcm), with an additional 12 bcm under discussion. Two gas pipeline projects: the expansion of the Trans-Adriatic Pipeline, and the development of EastMed, are expected to add another 20 bcm of import capacity in southern 3SI countries. With 2030 demand projections ranging from 61 bcm to 90 bcm (against 69 bcm in 2023), the increase in import capacity would be at least two times greater than the maximum anticipated demand growth. 

If current trends continue, the Three Seas region risks locking in significant overcapacity, stranding public investments and pulling resources away from urgently needed investments in electricity infrastructure, renewable energy deployment and energy efficiency.

These developments come at a time of record gas supply volatility, raising broader questions about the security and economic consequences of reliance on fossil gas. Going into 2025, the European gas price benchmark (the TTF) is around double its pre-crisis levels. Throughout 2024 alone, it rose 59%, from 30 to 48 EUR/MWh. The stability of gas supply into Europe is under threat as well, with North African imports from Algeria and Egypt facing technical difficulties in 2024, Nigeria’s gas exports constrained by security challenges, and, most importantly, tensions in the USA. Transatlantic relations have been at the heart of the 3SI’s creation, coinciding with a major increase in US LNG exports into the region. Yet the recent geopolitical shifts and domestic policy changes suggest that relying heavily on American gas imports presents strategic risks.

The 10th 3SI summit brings new opportunities

The 2025 Three Seas Summit in Warsaw will mark a decade of the initiative’s work towards regional collaboration. Much has been achieved already, including investments in two leading renewable energy companies in the region. But the 3SI’s tenth anniversary brings opportunity for a new opening that will set the stage for another decade of above-average economic growth fuelled by clean energy, electrification and collaboration. To achieve that, the Warsaw summit should consider the following actions:

• Aligning around the 2027 Russian gas phase-out

For the Three Seas region, phasing out Russian gas and reducing overall gas reliance is not just an economic imperative — it is a matter of national security and regional stability. Slovakia and Hungary are the most resistant to the Russian gas phase-out because of their geopolitical alignment and the financial benefit transits and discounted prices bring. However, this exposes the whole 3SI bloc to Russia’s energy blackmail. The Warsaw 3SI Summit will provide an opportunity to iron out plans for a complete decoupling from Russian energy imports by 2027 at the latest. 3SI should also take a strong position against the opening of Nord Stream 2 or the renewal of pipeline transits through Ukraine.

• Avoiding the overexpansion of gas infrastructure

To effectively phase out Russian gas, 3SI governments should prioritise measures to reduce gas demand through increasing investments in renewable energy, electrification, interconnection and energy efficiency, as well as optimising the use of existing gas infrastructure. These actions can be accelerated by leveraging EU and 3SI funding. At the same time, the scale of LNG investments needs to be aligned with gas demand trends, to avoid the inefficient use of public funding. 

• Initiating a flagship North-South interconnection project: the 3SI Transmission Highway

With vast wind resources located in the Baltic, Black, Aegean and Adriatic Seas, the region has a chance to become a clean energy superpower. By capitalising on the industrial backbone and world-leading tech labour force, 3SI countries can attract investments into sectors like clean industry, fintech or data centres. The 3SI should table a “Transmission Highway” project – coordinated grid investments that will allow for the transfer of clean power from the coastlines towards industrial facilities in Central Europe.

• Building momentum around energy hubs

Three of the 3SI members,  Estonia, Latvia and Lithuania, have set up to 100% renewable electricity targets for 2030 and have proposed a vision for a Baltic Energy Hub, aiming to boost their economies with joint clean energy investments. The 3SI is the perfect platform to build momentum around such initiatives. It can not only facilitate Poland’s connection to the Baltic Energy Hub, but also enable the participation of landlocked states like Czechia, Slovakia, Austria and Hungary through cross-border financing schemes such as PPAs, renewables auctions, flexibility markets, and schemes for joint financing of grids. The vision can be replicated in the Black Sea, with collaborative offshore wind and interconnection investments by Romania and Bulgaria.