Harmony Link

An agreement in December 2018 started it: on the 21st, the transmission operators of Lithuania and Poland, Litgrid and PSE, agreed to build a second connection between their grids. It was meant to sit alongside LitPol Link, until then the only line joining the Baltic states to continental Europe, and to add capacity for the day the Baltic grids left the Russian-run system and began running in step with the rest of the continent (the background is set out in the guide to Baltic synchronisation).

The first design was a subsea cable. According to the Harmony Link article on Wikipedia, it was to run about 330 km, roughly 290 km of it under the Baltic, from the Żarnowiec substation in Pomerania to Darbėnai near Kretinga, carrying 700 MW as high-voltage direct current. The Connecting Europe Facility set aside €493 million for it.

That plan did not survive the tender. In April 2023 the two operators cancelled the offshore procurement, citing a “significant increase in market prices for the cable and converter stations”, as PSE put it in July 2024. A feasibility study finished in June 2024 found that an overland AC line would be technically viable and give comparable stability. On 15 July 2024 PSE and Litgrid signed the agreement for the new version.

The redesign moves the project from the seabed to the border region. It is now a double-circuit 220 kV line from Ełk Bis in north-eastern Poland to a new substation near Gižai in Lithuania, following the Via Baltica road corridor. On the Polish side it brings two new substations, Norki and Wigry, and an upgrade of the existing Ostrołęka–Ełk Bis line.

What is settled is the shape and the date: the investment decision was due at the end of 2024, the construction tender in 2026, and energisation by the end of 2030. Neither operator has yet given a transfer capacity or a route length for the AC design. Anyone comparing it with the 700 MW cable should hold off until PSE or Litgrid gives a number.

Work had already begun at the Darbėnai end in June 2023, before the change of plan, so the Lithuanian coast keeps a small trace of the cable that was never laid.