An example wind turbine is provided that includes a shaft assembly, strut mounts coupled to the shaft assembly, airfoils directly or indirectly coupled to the strut mounts, and a generator assembly connected to the shaft assembly. The shaft assembly defines a central longitudinal axis of the wind turbine. The airfoils are capable of being positioned in a fully extended orientation and a fully retracted orientation. Rotation of the airfoils results in rotation of at least a portion of the shaft assembly to generate electrical current with the generator assembly.

In a vertical rotor apparatus that rotates in response to a moving fluid, a shaft defines an axis of rotor rotation. Rotor blades are longitudinally aligned in parallel with the shaft and each rotor blade defines an axis of blade rotation. A sensor generates a signal when any of the rotor blades are within rotor azimuthal angles of blade stall regions. A controller generates blade pitch information for the blade stall regions and an actuator, which is mechanically coupled to each of the rotor blades, alters blade pitch about the axis of blade rotation in accordance with the blade pitch information.

A fluid turbine blade device includes a vertical axis support base having a fulcrum-forming depression which acts as a first part, and a rotary assembly including a hub lid and a sleeve member rotatably surrounding the vertical axis support base. The hub lid has a projection acting as a second part and rotatably connected to the first part. The fluid turbine blade device further includes a plurality of blade modules mounted to the sleeve member and acted upon by fluid to drive the sleeve member to rotate, and a collision avoidance unit including a plurality of magnets disposed on the outside of the vertical axis support base and the inside of the rotary assembly to produce repulsive force.

A vertical axis wind turbine is supported by a durable and lightweight composite mast comprising a foam material and a support material, wherein the foam material is either (i) layered within or (ii) distributed among the support material. The foam material may be selected from polyethylene, cross-linked polyethylene, ethafoam, polyester, polyether, ether-like-ester, expanded polystyrene, and/or polyurethane. The support material may be selected from steel, metal, carbon nanotubes, and/or plastics such as polyethylene terephthalate, polyethylene, polyvinyl chloride, polypropylene, polystyrene, polylactic acid, polycarbonate, acrylic, acetal and/or nylon. A mixture ratio between the foam material and the support material may be at least 15:1. The mast may comprise a central core layer of foam and a peripheral layer of the support material. In an embodiment, adjacent layers of the central core layer and the peripheral layers alternate between the core and support materials.

The present device is a vertically oriented wind turbine blade having a rectangular simple curvilinear shaped blade, which includes a top edge, a bottom edge, an outer edge, an inner edge, an inner surface and an outer surface. The blade is formed using extrusion to approximate a uncompleted airfoil shape from the inner edge to the outer edge (relative to the turbine center or hub). The angle of attack, the solidity and the arms angle are designed to improve performance at low wind speeds.

Disclosed is a vertical axis wind turbine air concentration tower with reduced radar cross section. The air concentration tower has a polygonal outer perimeter, a pivot located at each vertex of the polygonal outer perimeter, and an inwardly-positioned rudder blade operatively connected at each pivot. Each inwardly positioned rudder blade has a first wind-neutral position, and is pivotable through a plurality of angles that adjust based on an incoming wind direction, such that the incoming wind is channeled to the vertical axis wind turbine, which is located approximately at a center area of the polygonal outer perimeter. A radar absorbent material is applied to the vertical axis wind turbine air concentration tower to reduce the radar cross section. The air concentration tower is designed to provide higher wind speed to the vertical axis wind turbine than the surrounding ambient air.

Solar thermal power generation equipment is equipped with a wind turbine, a compressor, a heat receiver that receives sunlight to heat a compressed medium from the compressor, a turbine driven by the compressed medium heated with the heat receiver, a power generator that performs power generation by driving of the turbine, a transmission mechanism that transmits the rotation of the wind turbine to the power generator, and a tower which supports these components. The wind turbine, the compressor, the turbine, and the power generator each constitute an array apparatus. The plurality of array apparatuses are arranged in a vertical direction.

A fluid turbine is described herein. The fluid turbine is subject to internal stresses, which can increase the frequency of maintenance or cost of construction, including fixing or replacing one or more components or increasing the amount of material used. One or more support arms of the fluid turbine can be provided in a given manner to generate a force during rotation that opposes one or more other forces, thereby reducing or eliminating the internal stresses exerted on the fluid turbine. For example, the one or more support arms can be provided in a given orientation or with given masses to generate the opposing force. In another example, the one or more support arms can be shaped or angled to generate an aerodynamic force.

A separable fluid turbine rotor turbine is described herein. The fluid turbine includes blades and support arms to adjoin the blades to a hub. The blades, support arms, or blades and supports can be assembled from a plurality of segments which are adjoined via one or more connectors. The connectors can be internal or external to the blade or support arm segments. Additional connectors can be used to adjoin the blades and support arms, the blades and the hub, and the support arms and the hub.

A vertical wind turbine with a plurality of vertical blades, which are each fastened to a respective vertical blade axis, such that they are pivotable around a respective blade rotation axis (C.sub.7) independently of one another, and are supported rotatable on a common circular path (K) around a vertical rotor rotation axis (C.sub.2), and a method for operating the vertical wind turbine, wherein pitch angles (β) of vertical blades of the vertical wind turbine, which are driven around a respective vertical blade axis, are predetermined. The pitch angle (β), at least in a partial load mode of the vertical wind turbine (1), is controlled such that the blades (7) rotate with an essentially constant tip speed ratio (λ).