The lengths and/or chords and/or pitches of wind turbine or propeller blades are individually established, so that a first blade can have a length/chord/pitch that is different at a given time to the length/chord/pitch of a second blade to optimize performance and/or to equalize stresses on the system.

A wind turbine (1) comprising a tower (2), a nacelle (3) and a hub (7) is disclosed. The hub (7) comprises a blade carrying structure (4) with one or more wind turbine blades (5) connected to thereto. Each of the wind turbine blades (5) defines an aerodynamic profile having a thickness which varies along a length of the wind turbine blade (5). Each of the wind turbine blades (5) is connected to the blade carrying structure (4) via a hinge (6) at a hinge position of the wind turbine blade (5), each wind turbine blade (5) thereby being arranged to perform pivot movements relative to the blade carrying structure (4) between a minimum pivot angle and a maximum pivot angle. The hinge position is arranged at a distance from the inner tip end (5a) and at a distance from the outer tip end (5b), and the thickness, or the thickness-to chord ratio, at the hinge position is larger than the thickness, or the thickness-to-chord ratio, at the inner tip end (5a) and larger than the thickness, or the thickness-to-chord ratio, at the outer tip end (5b).

To enable an increase in a torque amount applied to a blade with simple and low-cost means in a natural energy type power generator. An output reinforcement device of a power generator according to an embodiment is an output reinforcement device of a power generator including a rotor that includes at least one blade driven by renewable energy and a hub attached with the blade, the output reinforcement device including a casing that has a tubular shape and disposed to surround the hub, the casing having a through-hole through which the blade is inserted and being configured to rotate together with the rotor.

A drone with a horizontal rotor includes one or more rotor(s) (115, 116) which rotate in a horizontal plane, each rotor (115, 116) being equipped with one or more rigid or non-rigid blades (120, 121), the blade end being mounted on an electric motor (110, 111) with a propeller.

An apparatus for lifting a wind turbine blade to a rotor hub includes a blade holder configured to receive and support the wind turbine blade. A connection element is configured on the blade holder and is adapted to attach directly to a mounting surface of a wind turbine rotor hub. A lifting equipment attachment is configured on the blade holder to attach to the blade holder to lifting equipment. A first steering mechanism is operably connected between the blade holder and the lifting equipment attachment to control an orientation of the blade held by the blade holder with respect to the lifting equipment attachment.

A structure adapted to traverse a fluid environment includes an elongate body having a root, a wingtip, a leading edge and a trailing edge; and a plurality of rigid projections each extending from a respective position along the leading edge and/or the trailing edge generally along the same plane as a front surface of the body.

A fluid-redirecting structure includes a rigid body having an upstream end, a downstream end, and an axis of rotation, the rigid body incorporating a plurality of troughs each spiralled from a tip at the upstream end to the downstream end about the axis of rotation, the troughs being splayed with respect to the axis of rotation thereby to, proximate the downstream end, direct incident fluid along the troughs away from the axis of rotation.

A device and method for rotating a rotor of a wind power generator and a wind power generator are provided. The device includes at least two rotating units, and each of the rotating units includes a telescopic cylinder, a mounting base configured to connect a fixed end of the telescopic cylinder to a stand of the wind power generator, and detachably connected to the stand; and a pin arranged at a movable end of the telescopic cylinder, configured to be releasably fixed to the rotor, and configured to drive the rotor to rotate relative to the stand by a stroke movement of the telescopic cylinder.

A fluid-redirecting structure includes a rigid body having an upstream end, a downstream end, and an axis of rotation, the rigid body incorporating a plurality of troughs each spiralled from a tip at the upstream end to the downstream end about the axis of rotation, the troughs being splayed with respect to the axis of rotation thereby to, proximate the downstream end, direct incident fluid along the troughs away from the axis of rotation.

It is a general object of the present invention to provide a new and less expensive method of creating a horizontal axis wind turbine for electrical power generation. This approach is based on a tensioned support ring in the shape of a regular polygon. This support ring is well suited to the construction of large wind turbines because it is very light, strong, and cost efficient to create. Also provided are two types of rotor supporting tower structures including a wheeled version for land use and another that floats on water. Additionally, a method of using the support ring to generate electrical power from underwater currents. Further provided is a rope drive method of transmitting energy from the support ring to a generator below. Finally, two methods of controlling blade pitch. Both methods have similar automatic feathering systems to protect against excessive rotational speeds.