All four Baltica 2 offshore substations completed. 3,500 tonnes, five decks and more than 720 tests

After two years of production, all four offshore substations for the Baltica 2 offshore wind farm, developed by PGE and Ørsted, have been completed. Each weighs around 3,500 tonnes and has five decks. More than 720 commissioning tests were carried out across the four units to prepare their complex electrical systems for operation at sea.

Kamil Kusier executive editor 14.09.2026, 16:45 Reading time: 2 min

Aerial view of offshore electrical substations under tow by service vessels — fot. PGE Baltica

In brief

PGE and Ørsted have completed production of all four offshore substations for the Baltica 2 wind farm after two years of work. Each Baltica 2 substation weighs about 3.5 thousand tonnes, has five decks and houses transformers, switchgear and cooling systems. More than 720 commissioning tests in total were carried out on the four substations before installation in the Baltic Sea. The Baltica 2 substations will collect power from 107 Vestas turbines of 15 MW each and send it via export cables to the onshore station, and the roughly 1.5 GW farm is in the phase of foundation and onshore infrastructure construction.

The substations will be the heart of the wind farm's electrical system. Their job is to collect power from 107 turbines, step up the voltage and transmit it safely and reliably to shore. Without them, electricity generated at sea has no way of reaching the national grid, which makes the completion of all four units one of the most important milestones before installation begins in the Baltic.

The heart of a 1.5 GW farm

Baltica 2 is the largest Polish offshore wind project currently under construction. The farm, with a capacity of around 1.5 GW, is being built in the Baltic off Poland's central coast and will consist of 107 Vestas turbines of 15 MW each. The four substations will gather power from the whole farm and send it via export cables to an onshore substation, from where it will enter the transmission system.

The scale of the structures shows how different the project is from onshore power generation. A five-deck unit weighing 3,500 tonnes houses transformers, switchgear, cooling, control and protection systems, as well as accommodation for service crews. More than 720 commissioning tests mean that every one of those systems has been checked onshore before the substation is placed on its foundation at sea, where any repair is many times more expensive and more difficult.

Another step towards first power

PGE describes the completion of the substations as another important step bringing Baltica 2 closer to delivering renewable energy for Poland. The project is already in its construction phase, with work under way on foundations and onshore infrastructure, and the finished substations now await transport and installation at sea.

For the Polish offshore sector Baltica 2 is the reference project. It is where domestic ports, shipyards and service companies are gaining their first experience of handling an investment on this scale, and its schedule sets the pace for the whole first phase of offshore wind development in Poland.

Source: Gazeta Morska · Compiled by: Kamil Kusier