Exposed from behind this layer of shielding stone, turbines could potentially be dangerously destabilised by the effect of scour — the wave- and tide-driven sediment that can eat away at the seabed around fixed structures.

A team from the Technical University of Denmark (DTU) carried out model tests designed to mirror the impact of offshore conditions on the three-layer cover of “scour protection” placed around the 80 turbines at Horns Rev 1, which, three years after installation, had sunk by as much as 1.5