Aspects of the disclosure disclose a turbine that includes multiple rotating sails and multiple stationary sails. A mastless vertical axis wind turbine includes a first plurality of sails that are configured to rotate about a vertical axis under the influence of wind. A platform is coupled to the first plurality of sails. During operation of the mastless vertical axis wind turbine, the platform is in tension with the first plurality of sails at one or more points about a particular end of the first plurality of the sails. The mastless vertical axis wind turbine also includes a second plurality of sails having respective first ends that are coupled together and second ends that are each coupled to one or more stationary surfaces. The second plurality of sails are configured to remain stationary as the first plurality of sails rotate under the influence of the wind.

The present disclosure is directed to towerless vertical-axis wind turbines with pre-tensioned rotors. The present disclosure is further directed to a vertical-axis wind turbine (VAWT) with supported blade ends (e.g., Darrieus type) which replaces the center tower with tensioned supports, such as tensioned guy wires, and blade pre-load.

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.

Aspects of the disclosure disclose a turbine that includes multiple rotating sails and multiple stationary sails. A mastless vertical axis wind turbine includes a first plurality of sails that are configured to rotate about a vertical axis under the influence of wind. A platform is coupled to the first plurality of sails. During operation of the mastless vertical axis wind turbine, the platform is in tension with the first plurality of sails at one or more points about a particular end of the first plurality of the sails. The mastless vertical axis wind turbine also includes a second plurality of sails having respective first ends that are coupled together and second ends that are each coupled to one or more stationary surfaces. The second plurality of sails are configured to remain stationary as the first plurality of sails rotate under the influence of the wind.

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.

The present invention is directed to an improved vertical-axis wind turbine rotor that provides a more constant shaft power output than similar turbine rotors of the prior art. In a preferred embodiment, it provides four tiers of blade sets, with each set disposed at a different elevation than each other set. Each blade set may be offset at an angle from adjacent blade sets. A partition plate may be disposed between adjacent blade sets. The partitions provide structural stability and enhanced rotor performance characteristics.

A mastless vertical axis wind turbine that comprises a plurality of sails that rotate about a vertical axis under the influence of wind. A platform is connected to and in tension with the plurality of sails at one or more points about the bottom of the plurality of the sails. Also, an external frame is connected to and in tension with the plurality of sails at one or more points about the top of the plurality of the sails. The external frame itself comprises a plurality of legs that converge above the plurality of sails at a central point about the vertical axis of rotation and extend beyond the path swept by the plurality of sails. A coupling mechanism connects one or more of the plurality of legs to the plurality of sails and allows the sails to rotate about the vertical axis of rotation while the legs remain stationary.

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.

Vertical axis wind turbines are provided having foil design and geometry that facilitates lift, torque and laminar flow along a 360 degree radial. Contemplated foils are non-planar, and have a chord length that is at least three times greater than a distance between a trailing end of a leading foil, and a leading end of a trailing foil. Additionally or alternatively, the foils are located away from a turbine axis at a distance that is about 2.9-3.5 times greater than a chord length of the foils. In some embodiments, the foils are circumferentially distributed via one or more laminar stall vanes.

A vertical shaft wind turbine that is superior in a rotational startability, even at a low wind speed, and is suited to a wind power generator that has high rotational torque. Each blade is an upper-and-lower-ends fixed type vertically long blade which is suitable for use as a wind turbine or a water turbine. The string length and thickness of an upper-and-lower-ends fixed type vertically long blade (8) that is fixed upper and lower ends to a vertical main shaft (7) gradually decrease from a main part (8) thereof to tips of the upper and lower inwardly curved inclined parts (8B, 8B), and a cross section of the main part (8A) is a lift type. A thickness of the cross-sectional shape is continuously and gradually thins from the main part (8) to the tips of the inwardly curved inclined parts (8B, 8B).