Korsnäs

In 2024, Vattenfall and Metsähallitus commenced geophysical surveys for the Korsnäs offshore wind project, including detailed mapping of the offshore wind farm area and two alternative export cable corridors that will connect the project to the onshore power grid. Contractors GEOxyz and Arctia are using survey vessels Kaiku, Keila 1 and Geo Ocean VI equipped with multibeam echosounders, sub-bottom profilers, side-scan sonar, magnetometers and sediment sampling to characterise seabed morphology and sub-seabed geology down to 100 metres, providing input for the environmental impact assessment and engineering of the Korsnäs Export transmission system.

By early December 2024, geophysical surveys were underway at the Korsnäs offshore wind farm site near Vaasa, carried out by GEOxyz and Arctia to examine seabed morphology and shallow geology along the wind farm area and cable routes, providing input for the environmental impact assessment, archaeological screening, and preliminary foundation design.

In September 2024, Vattenfall signed a letter of intent with the Port of Kaskinen to explore using the port for logistics during the construction phase of the Korsnäs offshore wind farm and later for wind turbine maintenance; Vattenfall has also signed a similar letter of intent with the Port of Vaasa as part of wider port infrastructure planning for the project.

Vattenfall and Metsähallitus awarded GEOxyz and Arctia a geophysical research contract for the Korsnäs offshore project, including mapping of a 280 km² offshore wind area and two alternative corridors for the export cables that will connect the site to the onshore power grid. The work, using Arctia survey vessels Kaiku and Keila1 and GEOxyz’s Geo Ocean VI, will provide seabed and sub-seabed data required to engineer the Korsnäs–mainland transmission connection.

Vattenfall and Metsähallitus awarded GEOxyz and Arctia a geophysical research contract for the Korsnäs offshore wind farm, covering mapping of a roughly 280 km² offshore area and two export cable corridors using survey vessels, multibeam echosounders, sub-bottom profilers, side-scan sonar, magnetometers, sediment sampling, UHRS seismic surveys, and bathymetric LiDAR.

The Municipality of Korsnäs conducted a public consultation on the participation and evaluation plan (OAS) for the wind power partial master plan covering the Korsnäs offshore wind farm. The OAS, which sets out how stakeholders can participate and how impacts will be assessed in the zoning process, was put on display and remained available for comments until 24 May 2024, with the municipality compiling opinions and statements received.

The South Ostrobothnia ELY Centre opened the statutory public consultation on the environmental impact assessment (EIA) programme for the Korsnäs offshore wind farm and its subsea export cable routes. The EIA programme and related materials for the wind farm area (up to 150 turbines offshore Korsnäs and 1–2 offshore substations plus two alternative cable corridors) were placed on public display from 4 April to 24 May 2024, during which stakeholders could submit opinions and statements to the ELY Centre.

The South Ostrobothnia ELY Centre also initiated public consultation on the EIA programme for the onshore electricity transmission associated with the Korsnäs offshore wind farm. From 4 April to 24 May 2024, the EIA programme and route alternatives for new 400 kV overhead lines and associated onshore substation works from the cable landfall in Korsnäs towards Fingrid’s Tuovila and/or the planned Åback substation were available for public review, and comments could be submitted to the ELY Centre.

An intensive new bird survey campaign in the Korsnäs offshore wind farm area began at the end of March 2024, using mainly fixed-wing aircraft along with GPS tracking and migration observations to determine which bird species use the area, in what numbers, where and when, so the wind farm can be planned to minimise ecological disturbance.

The multi-year baseline bird surveys for the Korsnäs offshore wind farm and marine cable routes, covering the 2021–2023 period, were completed and compiled as supporting material to the 2024 Environmental Impact Assessment programme.

In December 2022, Metsähallitus reached an agreement with Vattenfall, selecting Vattenfall as its project partner through an international tender to develop and construct the Korsnäs offshore wind farm on state-owned territorial waters off the west coast of Finland, establishing the joint development structure for the project.

In December 2022, Metsähallitus reached an agreement with Vattenfall, which won an international tender, for the development and construction of the Korsnäs offshore wind farm, making Vattenfall the partner to build and operate what is planned as Finland’s first open-sea, large-scale offshore wind project.

The Finnish Government granted Metsähallitus permission to lease seabed areas for two large-scale offshore wind farms, including the Korsnäs project located about 15 km off the coast, providing seabed access for further project development.

Baseline ornithological surveys for the Korsnäs offshore wind farm and associated sea cable routes commenced in 2021, as documented in the study series "Korsnäsin merituulipuiston linnustoselvitykset 2021–2023", to characterise bird populations and movements in the project area.

The municipality of Korsnäs approved Metsähallitus’ planning initiative for an offshore wind farm on public waters about 15 km off the coast, confirming the specific project site within the pre-designated offshore wind area.

Metsähallitus, acting as project developer for the Korsnäs offshore wind power park, appointed AFRY to deliver the Environmental Impact Assessment, prepare the local master plan, and provide technical engineering for the project over the 2020–2024 period.