LitPol Link

On 9 December 2015, its first day in service, LitPol Link carried up to 200 MW from Poland to Lithuania. The link raised Poland’s interconnection level from 2% to 4%, according to the LitPol Link article.

The line runs on land. According to EPSO-G, the group that owns Litgrid, 51 km of the 400 kV line lies in Lithuania and 112 km in Poland, 163 km from Alytus to Ełk. Behind it, a 53 km 330 kV line links Alytus with Kruonis. Counting that section, the Wikipedia infobox gives 341 km; this page gives the operator group’s 163 km for the cross-border line.

For its first decade the link needed a large machine in the middle. Lithuania ran in step with the Russian-controlled IPS/UPS system, Poland with Continental Europe, and the two could not be joined directly. So a back-to-back converter station was built in Alytus, 200 metres long and 170 metres wide. Hitachi Energy, which supplied it turnkey as ABB, describes a single 500 MW block with thyristor valves, laid out so that a second 500 MW block could be added later. The line itself is AC; the converter turned the power into DC and straight back, in phase with the other side. The HVDC explainer describes the method.

That changed in February 2025, when the Baltic states disconnected from the Russian system and synchronised with Continental Europe. From then on LitPol could run as a plain synchronous line, and the Alytus converter became redundant. The guide to Baltic synchronisation tells that story.

The groundwork for that switch was laid years earlier. In November 2021 Litgrid finished a €22.5 million expansion at the Lithuanian end, The Baltic Times reported: the LitPol switchyard and the Alytus substation were rebuilt, nearby 330 kV and 110 kV lines were reconstructed, and three 600 MVA autotransformers were installed to tie the 400 kV line directly into the 330 kV grid. The work was part-funded by the EU’s Connecting Europe Facility, and Lithuania’s energy minister said at the time that the country could no longer be left an isolated energy island. The headline over that report called it a synchronisation-ready link, three years before the switch.

The project cost €340 million, well above the pre-feasibility estimate of €237 million. The feasibility study was finished in September 2002 and construction began on 5 May 2014, so the gap between study and spade was almost twelve years. LitPol is owned by a joint venture of PSE and Litgrid, based in Warsaw. A second line, Harmony Link, was first planned as a subsea cable and was redesigned in 2023 as an overland 220 kV connection from Ełk Bis to Gižai, due by the end of 2030.