The company’s deep-draught vertical-axis SeaTwirl, which it foresees scaling up to 10MW, features upward, angled rotor blades set around a hollow, ring-shaped “torus” that is trussed to a slender semi-submersible tower. The whole thing is anchored to the seabed with a three-point mooring spread.

Minimalist in its architecture, the turbine is designed to rotate as one unit from blade-tip down the length of its axle to turn a direct-drive permanent-magnet generator at its base.

Seawater plays a central role in the workings of the turbine.