RWE Deploys Artificial Reefs at Offshore Wind Farm in the Baltic Sea

RWE has installed artificial reefs at its Kårehamn wind farm, off the Swedish coast, to assess marine life settlements as part of a pilot study on biodiversity at offshore wind farms.

In partnership with Linnaeus University and cable service provider Baltic Offshore Kalmar, RWE is conducting a pilot study which has just entered practical phase with the installation of 180 carbon neutral, plastic-free reef cubes.

The reef cubes were designed and manufactured by ARC Marine, a leading supplier of nature inclusive solutions.

The cubes, which vary from 15x15 cm to 75x75 cm in size, have been installed at the 48 MW Kårehamn offshore wind farm, which features 16 turbines located 7 km off the Swedish coast.

The objective of the study is to assess how artificial structures at offshore wind farms can promote biodiversity and support ecosystem services, such as habitat provision, nutrient cycling and water quality, hence contributing to the restoration and preservation of the Baltic Sea.

The study started in 2023 with the collection of information for the baseline scenario. This included a survey of the underwater area including sampling from the seabed and eDNA sampling to assess the ecosystem and to identify the species in the region, such as mussels, vegetation and fish.

By understanding the biodiversity, the team could predict the possible impacts of the subsequent project phases more effectively and plan accordingly.

The rationale for selecting this location is the previously observed development of species on the foundations of the wind turbines. The intention is to create artificial reefs for habitats and species to grow and hide in, with a special focus on macroalgae, blue mussels and various species of fish.

In the colonisation phase from 2024 to 2026 the submerged cubes and the surrounding ecosystem will be examined. This will provide valuable data and learnings for the sustainable design of future offshore wind projects.

“As a global leading offshore player, we are responsible for operating wind farms in harmony with nature. To deliver green electricity, we invest billions of euros annually in wind power. We are committed to expanding our portfolio in an environmentally friendly way. With this in mind, we have set ourselves ambitious sustainability targets.

“This study is a significant step forward. Assessing how our activities may help to promote biodiversity will enable us to take the long-term sustainability of offshore wind farms to the next level,” said Sven Utermöhlen, CEO RWE Offshore Wind.