Ecofys has ingeniously combined two types of rotor on a single axis of rotation. The so called Wave Rotor is able to convert not only tidal currents, but also waves into electricity. The latter is possible because waves are made up of circulating water particles.

The energy from tides and waves is directly converted into rotational movement, driving a generator. Therefore the system does not need any inefficient conversion steps.

In order to tap the kinetic energy in waves, the following two rotors are combined: a Darrieus rotor with more or less vertical (or slanted) rotor blades and a Wells rotor which has radial blades. These are respectively an omni-directional and a bi-directional rotor which are known to operate in fluctuating currents.

This simple and light, yet robust construction has the added benefit of having little surface area exposed in the sea, thus reducing the loads in extreme storm conditions.

Wave Rotor scale test in wave tank at NaREC (UK) in 2004