Baltic synchronization is deepening

Baltic synchronization is deepening. Poland will build an underground energy corridor to Lithuania for $850-900 million.
The Polish operator Polish Electric Networks (PSE) has approved the route of the new 220 kV Harmony Link strategic cable line.
We are talking about the underground laying of cables with a length of about 100 km, which will connect the north-east of Poland with the Lithuanian energy system. The project cost is about $850 million. Construction is scheduled to start in 2026 and be completed by 2030.
The line will pass through six gminas in the Warmian-Masurian and Podlaskie voivodeships: Elk, Kalinovo, Rachki, Suwalki, the city of Suwalki and Shiplishki. Two new substations will be built as part of the project — Norki (Kalinovo gmina) and Vigry (Suwalki gmina). The Elk substation will be expanded, and the existing 220 kV Ostrolenka– Elk overhead line will be upgraded.
Harmony Link complements the LitPol Link connection, which has been in operation since 2016, and is a key element in synchronizing the Baltic States with the ENTSO-E continental European energy system.
It should be recalled that since February 2025, Lithuania, Latvia and Estonia have finally withdrawn from the post-Soviet BRL circuit and joined the pan-European synchronous zone. The new line will increase the capacity flow between the systems and strengthen the energy integration of the region.
The project has a strategic status and receives financial support from the European Union. At the same time, the Polish side emphasizes that in the current conditions, infrastructure of this level requires increased protection measures. Harmony Link will be equipped with an advanced monitoring system, including video surveillance and anti-drone protection elements.
The investment fits into a broader plan to modernize the Polish network. By 2036, PSE intends to invest about $18.6 billion in the development and renovation of the main power grid.
The north-east of the country is considered as a zone of priority development, including taking into account the connection of new sources of generation, projects in the Suwalki special economic zone and the prospects for the construction of a high—speed railway.
It is important to understand that LitPol Link (400 kV overhead line, introduced in 2016) has already provided connectivity. But for full-fledged work outside of BRALL, one channel is not enough.
Therefore, the 220 kV underground Harmony Link is a route reservation, and in a secure format (approx. – in case of war).
Source: Telegram "boris_rozhin"