Environmental permit for Skyborn Renewables offshore wind park, Storgrundet

In September 2023, after a main hearing where NIRAS contributed with marine biological expertise, Skyborn Renewables received the environmental permit from the Swedish Land and Environment Court to build the Storgrundet Offshore wind farm, marking an important milestone in realising the project. The permit allows to install a maximum of 51 wind turbines with a maximum total height of 290 meters. The Storgrundet offshore wind farm is estimated to produce 3–3.5 TWh of electricity annually, equivalent to household electricity for approximately 700,000 homes.

NIRAS has played a central role in the preparation of an environmental impact assessment (EIA) for the wind farm, including the planning and implementation of environmental surveys. This has involved fieldwork with surveys of both fish stocks and bottom-dwelling animals and plants, as well as detailed calculations of wave exposure. Additionally, we contributed to the preparation of materials for public consultations and wrote parts of the EIA, which details the area's environmental values and analyses the potential environmental impacts of the wind farm.

"From a marine biological perspective, Storgrundet is a suitable location for establishing a wind farm. We have conducted an extensive survey program and now have thorough knowledge of the area, which makes us confident in making such an assessment. Throughout the project, we have had excellent cooperation with Skyborn Renewables, and they have followed our recommendations on the necessary surveys to conduct. Based on this data, it was straightforward to justify our assessments during the review in the Land and Environmental Court," says Martin Isaeus, project manager at NIRAS in Sweden.

Skyborn Renewables is now planning to apply for grid connection of Storgrundet Offshore to both the national transmission grid and the hydrogen project SoutH2port in Vallvik, Söderhamn Municipality. SoutH2port is a collaborative project between ABB, Lhyfe, and Skyborn Renewables with the goal of exploring opportunities to supply the Swedish energy system with fossil-free fuels and storage.

NIRAS contributes through studies of marine biology and potential contaminants in the sediments of the cable corridor. The studies serve as the basis for the environmental impact assessment of the grid connection.

Historical Review

The 2023 permit for Storgrundet was Skyborn Renewables' second permit to establish offshore wind power in this area. As early as 2010, Skyborn Renewables, then wpd, obtained a permit to build a wind farm. One of the decisive factors was the scientific investigation where NIRAS, then AquaBiota, demonstrated that the impact of the construction work on herring spawning in the area would only have a marginal effect on the herring population. An environmental monitoring program for the park was initiated, but the project was put on hold in 2012.

The project was resumed in 2018 when Skyborn Renewables decided to apply for a new permit to build the wind farm, this time with larger turbines and in a larger area. In 2020, NIRAS conducted new field surveys, which included eDNA analyses and fish sampling to map fish populations and assess environmental conditions in the new wind farm area.