Poland and Lithuania seek a new route for a key cross-border power line

The Harmony Link HVDC power line, which is intended to connect the Polish substation at Zarnowiec in the Pomeranian Voivodeship with the substation at Darbėnai in Lithuania’s Kretinga area, will not be built as an undersea cable, as originally planned. Both sides are now looking for a new route.

Preparatory work on the project began in 2019. The original plan, which was due to be completed in 2028, was considered a key—and, to date, the largest—infrastructure project needed to desynchronize the Baltic power system from Russia’s.

The project was expected to significantly improve the energy security of all three Baltic states and contribute to the future integration of renewable energy sources. The plan involved a 330 km-long high-voltage direct current (HVDC) cable with a transmission capacity of 700 MW routed under the sea. However, it will not go ahead because of the high costs.

Litgrid and PSE, the electricity transmission system operators in Lithuania and Poland, are now considering alternative options. One possibility is to lay the cable overland, which would reduce costs and speed up the project. One potential route would follow the planned Rail Baltica railway line between Poland and Lithuania. A specific route decision is expected in the first half of next year, with completion expected by 2030.

Estonia, Latvia and Lithuania are also considering various other options for connecting to Europe’s electricity grid, overland or undersea. In August this year, the countries signed an agreement to connect their grids to the European grid and disconnect them from the Russian and Belarusian grids by the beginning of 2025.

After LitPol Link, the Harmony Link line is expected to become the second electricity interconnection between Poland and Lithuania, linking the Baltic transmission system with the grid of continental Europe.