Baltic Power's offshore substation structures have left the port of Gdynia. They are now sailing for outfitting.

Manufactured at shipyards in Gdynia and Gdańsk, the steel structures of two offshore substations of the Baltic Power wind farm are now completed and have sailed off to the port of Aalborg (Denmark) for the outfitting. They will be installed in the Baltic Sea this autumn.

Offshore substations are a key component of the Baltic Power wind farm's infrastructure. They will collect the energy generated by 76 turbines of 15 MW each and transmit it to the onshore grid. Each substation consist of two main elements: the foundation and the topside, the actual structure installed above it. A single fully equipped topside will weigh about 2,500 tonnes.

The steel frameworks of the substations, referred to as "houses," were produced by Baltic Industrial Group at shipyards in Gdynia and Gdańsk. Measuring 20 x 30 x 40 metres, these structures are comparable in size to a four-to five-story apartment building. Despite their massive scale, each station is fully assembled and outfitted on land before being transported to sea for installation.

The completed structures were moved onto a barge using SPMT (self-propelled modular transporter) platforms and are now sailing to Aalborg for outfitting. During this stage, various levels of the substation will be equipped with key components, including main transformers, high-voltage switchgear, auxiliary switchgear, control and monitoring systems, and other auxiliary equipment necessary for safe and efficient offshore operation. SEMCO is responsible for this phase of the project.

This autumn, the substations will return to the Baltic Sea, where they will be installed 23 kilometres off the coast of the Choczewo municipality. They will be installed onto monopile foundations using transition elements and then connected via submarine cables to both the wind turbines and export cables leading to the onshore station.

The construction of offshore substations is one of the key work packages of the Baltic Power farm, with Polish companies playing a major role. Over the farm’s entire lifecycle -  from project development to its estimated 30 years lifespan of operation - at least 21% of the work will be carried out by Polish companies. In addition to offshore substations, Poland is also responsible for manufacturing foundation components and cables, among other key elements.

The Baltic Power offshore wind farm, a joint venture between ORLEN and Northland Power, is the most advanced offshore wind project in Poland and the only one to have reached the construction phase. In 2023, the project received a final investment decision (FID) and financing from 25 international institutions under a project finance model. Construction of the farm's onshore infrastructure has been underway since 2023, and offshore installation work started in early 2025. Baltic Power will be one of the first farms in the world to install 15 MW wind turbines. With planned completion in 2026, Baltic Power will be the first Polish offshore wind farm operating in the Baltic Sea. The investment will cover about 3% of the country's energy needs (equivalent to the needs of more than 1.5 million households). Baltic Power will generate about 4,000 GWh of zero-emission electricity per year, reducing CO2 emissions by about 2.8 million tonnes per year compared to production from conventional sources.