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, particularly vertical axis, whose diameter is extensible and retractable, either from the length of the arms or the angle of the blades, or both, has advantages in operating in low wind speed regimes and surviving in high wind speed, regimes. The current application describes how to construct such a turbine, particularly the control mechanisms and the optimal aerodynamic configurations of the blades.

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 blade adapter for rotor blades of wind turbines, for increasing the rotor diameter, has a first end for attaching to the rotor hub, and a second end, spaced apart in the axial direction, for connecting to the blade root of a rotor blade. In addition, the blade adapter, at its first and second end, has a pitch circle for connecting to the rotor hub or to the rotor blade, wherein the wall of the blade adapter extending in the axial direction is open outwardly, in the form of a truncated cone, from the first end toward the second end, in at least one portion.

The invention relates to a wind turbine system (WTS) comprising at least two blade rotors rotatably mounted to a nacelle (rotatably) mounted to a tower provided above a (water) level. The WTS can be characterised in that the blade rotors are interconnected by one or more retractable blades. The retractable blades can have variable properties, they can be stowable, can be able to weathervane, and can comprise a defined construction, a working mean. The blade rotors can rotate in the same and/or opposite directions. The components can be fabricated of defined materials. The WTS can be provided in an array and it can be couplable or coupled with various mechanocomponents and/or electrocomponents. A method for varying a design point of the disclosed wind turbine is proposed.

A vane device includes a rotary shaft and a plurality of vane units angularly spaced apart from each other relative to the rotary shaft. Each of the vane units includes a grid frame that has grid spaces, and a plurality of vanes respectively disposed adjacent to the grid spaces. Each vane is swingable between a cover position and an open position. The size of the vanes decreases along a radial direction from a vicinity of the rotary shaft to a distance away from the rotary shaft.

A windmill for generating electricity is described, which contains several improvements that enable the blades of the windmill to be much wider than conventional electricity-generating windmill blades. The rotor containing the blades will also change direction to capture the largest amount of wind energy available. The windmill includes a shroud surrounding the blades, which increases the wind velocity through the blades. Support structures for the windmill are described, and also a method of using the windmill to store electricity to use later is shown. The windmill is more stable than conventional windmills. A method of using a windmill to generate electricity is also described.

This invention relates to an arrangement for a surface area adjustment of a reciprocating wing system in a wave energy recovery system where the wave energy recovery system comprises at least a body, a set of wings fastened to a support means that is hinged at its lower ends onto the body to make a reciprocating motion in response to kinetic energy of waves or tidal currents, and a power-take-off means. The arrangement comprises at least adjustment means capable to adjust the total effective surface area of the wings.

The present subject matter directed to a rotor blade assembly for a wind turbine having at least one rotatable aerodynamic surface feature configured thereon. The rotor blade assembly includes a body shell including a pressure side surface and a suction side surface extending between a leading edge and a trailing edge. The aerodynamic surface feature is disposed adjacent to the pressure side surface, the suction side surface, and/or both. In addition, the surface feature may have a generally airfoil-shaped cross section. As such, an actuator can be configured at least partially within an internal volume of the surface feature, the actuator being configured to rotate the surface feature relative to the body shell.

A stability of a vertical axis combined water/wind turbine motor composed of a drag type and a lift type is improved by releasing convex surface resistance produced by a drag-type blade going against a fluid and increasing rotation torque by the reduction in resistance; during high-speed rotation equal to or higher than a fluid speed, all wing surfaces of the drag type are naturally brought into a released state as a result of being pulled by the lift-type blade rotation speed; and a danger at the time of increasing a fluid speed can be avoided by producing a fully-released state by rolling in feathers of a drag-type wind surface configuration, by decreasing the entire volume by folding wing surfaces to the rotation axis side, or by decreasing the entire structure by drawing feathers on the wing surface toward the rotation center.