EnergyOMNI's Perspectives I Nature-Inclusive Design in Offshore Wind Farms: Enhancing Environmental Sustainability

Edited by EnergyOMNI

Low-Carbon Artificial Reefs: An Ecological Win-Win for Scour Protection and Marine Habitats

Offshore wind developer RWE, in partnership with ARC Marine, has launched the Reef Enhancement for Scour Protection (RESP) initiative. In October 2025, the project deployed 75,000 specially designed "reef cubes," a nature-inclusive design, at the base of turbines in RWE's Rampion Offshore Wind Farm in the United Kingdom. These structures not only protect the turbine foundations from erosion and scour but also provide habitats for marine life.

RWE and ARC marine launched the world's first full-scale pilot project in July. The project took eight years to get off the ground. In the last few days, around 75,000 Reef cubes ranging in size from 15cm to 35cm. The developer says that at just one of the Rampion turbines, the reef cubes are providing a habitat surface area of 25,000 square meters. The project aims to test the feasibility of using artificial reefs to replace traditional rock-based scour protection layers, seeking a sustainable, win-win solution. RWE stated that it will continue to monitor the scour protection performance and the development of biodiversity over the next five years.

Last year in May, RWE and ARC marine installed 180 reef cubes for testing at RWE's 48 MW Kårehamn offshore wind farm in Sweden. According to ARC Marine, the reef cubes have been designed with a chamber in the middle and a honeycomb texture on the outside to encourage marine life to use them. The intention is to replicate the complexity in a natural reef, so reef building species can be settling on it. It is hoped species such as ross worms, anemones, oysters and mussels will live on the reef cubes and that fish and crustaceans will also come over time. The low carbon reef cubes are made near Truro from recycled waste aggregate from Cornish clay mines. A crane placed the cubes into a hopper which then saw them fed through a pipe 25m (82ft) down to the sea floor, a process which took two days.

Besides RWE, Ecowende's Hollandse Kust West wind farm have officially commenced with the start of eco-friendly scour protection works in September. Wind farm developer Ecowende and its partner Van Oord has developed four innovative scour protection designs. These designs use stones of varying sizes, including a grading of 60–300 kg to create larger openings and crevices between the rocks.

By installing artificial reefs around offshore wind farms and offshore substations, developers can not only prevent seabed erosion but also provide new habitats for fish and other marine species. These gaps provide shelter for fish and other marine species, while specially designed bays along the scour protection extend the length of habitat available.

Installing Artificial Reefs Around Wind Farms And Offshore Substations To Increase Fish Habitats

Scientific research has shown that offshore wind turbines can create a "reef effect" similar to that of artificial reefs, attracting fish populations. In addition, the fishing restrictions within offshore wind farm areas often generate effects comparable to Marine Protected Areas. However, in addition to installing wind turbines, some wind farms have also placed artificial reefs to create more habitats for marine life. Danish developer Ørsted deployed a dozen 3D-printed reef structures on the seabed between the wind turbines at our Anholt Offshore Wind Farm in Denmark in 2022. The reefs, which are about 1 cubic meter in size and weigh up to half a ton, vary in their exact shape to best imitate natural habitats. The biocompatible reefs made from natural materials and had a wedding cake-like appearance that allow space for the fish to swim in and out of hiding spaces. In July 2024, the reefs had been in place for two years, the result is a confirmation that the man-made reefs can improve the resilience of the ecosystem and elsewhere by creating a habitat for cod and other species.

Besides wind farms, offshore substation can be a place for artificial reefs placing. Two types of artificial reefs have been placed near the Hollandse Kust west alpha jacket, the offshore transformer platform, by TenneT in October 2023. Six reef cubes are attached to one frame. Hollow square blocks made of nature-friendly recycled material with round holes in the walls. On the other steel frame are six reef balls, a similar structure but in the shape of a ball. These artificial reef structures create potential spots where coral and algae settle. The aim of the trial is to investigate which shape - ball or cube - works best in the waters off our coast.