Patent ID: 8866327

Claim:
A device for the utilisation of wave energy, which device comprises a Darrieus rotor having at least two Darrieus rotor blades, wherein the Darrieus rotor has a Darrieus solidity (σD) calculated under the formula σD=N·Adb/Ad, wherein N=the number of Darrieus rotor blades; Adb=the surface area of each Darrieus rotor blade; and Ad=the effective cross-sectional area of the Darrieus rotor sweep; and a Wells rotor having at least two Wells rotor blades, wherein the Wells rotor has a Wells solidity (σW) calculated under the formula σW=N·Awb/Aw, wherein N=the number of Wells rotor blades; Awb=the surface area of a Wells rotor; Aw=the effective swept surface area of the Wells rotor; wherein the Darrieus rotor and the Wells rotor are rotatable about a common axis of rotation with the effective cross-sectional area of the Darrieus rotor sweep containing the common axis of rotation and with the effective swept surface area of the Wells rotor being perpendicular to the common axis of rotation, and the Wells solidity (σW) is larger than or equal to the Darrieus solidity (σD).