RWE and TotalEnergies have signed a deal with UK-based ARC Marine to supply 66 “reef cubes” for the OranjeWind offshore wind farm in the Dutch North Sea, marking one of the largest artificial reef deployments at a European wind project to date.

The concrete structures will be installed around 11 turbine foundations once offshore construction concludes, following the start of foundation work in 2026. The partners said the aim is to support local marine biodiversity by creating new habitat at the wind farm.

The cubes, each weighing nearly six tonnes and standing 1.5 m high, are made from low-carbon recycled materials and incorporate shell fragments to encourage native oyster settlement. In total, the installation will add around 1,440 sq m of surface habitat. ARC Marine said the design has proven stable and easy to transport and deploy, and the units will remain in place for the full operational life of the wind farm.

Previous trials in the North Sea showed a wide variety of species colonising the reef cubes, with cod and native oysters identified as key species expected to benefit at OranjeWind. The developers expect wider ecological gains across the surrounding marine community.

Tobias Keitel, CTO of RWE Offshore, said the project aligns with the company’s broader biodiversity commitments. TotalEnergies’ offshore wind construction director Jean Gavalda added that the deployment demonstrates the partners’ intention to integrate ecological measures into large offshore developments.

ARC Marine CEO Tom Birbeck said the order marks a move from pilot-scale testing to commercial-scale implementation of “nature-inclusive design”, calling it a major step forward for the offshore wind sector.

The 795 MW OranjeWind project, located 53 km off the Dutch coast, is due to begin offshore construction in 2026 and start operations in early 2028. The project will supply power to the equivalent of 1m Dutch households and includes investments in flexible demand assets such as batteries, e-boilers and electrolysers.

Earlier this year, RWE installed around 75,000 reef cubes at its Rampion wind farm in the UK in another large-scale biodiversity effort.