A power generating roof ventilation device for venting a structure and generating an electrical current includes a tube, which is mountable to a roof of a structure so that the tube is in fluidic communication with an interior space of the structure. The tube extends from the roof. A generator is engaged to and is positioned within the tube so that a drive shaft of the generator extends from the tube. A plurality of blades is engaged to the drive shaft. The blades extract energy from air passing over the blades. The drive shaft is rotated and an electrical current is generated by the generator. Simultaneously, air is extracted from the interior space of the structure.

A savonius wind turbine including a rotational shaft and a compound blade operatively coupled to the rotational shaft is provided. The compound blade includes a primary blade portion and a secondary blade portion. The primary blade portion extends between a first end and a second end and defines a primary concave surface therebetween. The secondary blade portion is coupled to the primary blade portion between the first end and the second end. The secondary blade portion defines a secondary concave surface configured to generate a torque about the rotational shaft.

A fluid turbine may include a vertically-orientable shaft having at least one opening extending transversely therethrough, a first blade portion configured for vertical orientation on first side of the shaft, a second blade portion configured for vertical orientation on a second opposite side of the shaft, at least one rod extending through the shaft opening and connectable at a first end to the first blade portion and at a second end to the second blade portion. A reinforcing sleeve may extend through the shaft opening and may be interposed between the rod and the shaft opening for reinforcing at least one of the shaft, the at least one shaft opening, or the rod against forces exerted by the first and second blade portions when fluid impacts the first and second blade portions.

A rotor for a wind power installation and method for operating a wind power installation are provided. The rotor includes a first and a second blade support and a first set of at least two rotor blades. The rotor blades of the first set have a vane-shaped configuration and extend helically from the first to the second blade support. The rotor includes at least one additional blade support and at least one additional set of at least two rotor blades. The rotor blades of the additional set have a vane-shaped configuration and extend helically from the second to the additional blade support. The arrangement of the rotor blades of the additional set is arranged with an angular offset to the arrangement the rotor blades of the first set.

A vertical-axis wind turbine. The vertical-axis wind turbine comprises a central rotatable hub having multiple wingspars to mount multiple airfoils, a pushrod firmly and rigidly positioned via each wingspar to convert a linear kinetic wind energy from the airfoils to the pushrods to the rotational energy of the central rotatable hub, and an axle attached to the central rotatable hub. The vertical-axis wind turbine rotates the multiple airfoils configured with two airfoils per wingspar, wherein at least two airfoils are mounted on each wingspar. The airfoils work when they are blown upon by applying fluid force to the pushrod and wingspar, one airfoil is blown and held into the maximum angle of attack to perform work to be pushed by the wind, and its opposite is blown and held into the minimum angle of attack to pull back in the wind.

A savonius wind turbine including a rotational shaft and a compound blade operatively coupled to the rotational shaft is provided. The compound blade includes a primary blade portion and a secondary blade portion. The primary blade portion extends between a first end and a second end and defines a primary concave surface therebetween. The secondary blade portion is coupled to the primary blade portion between the first end and the second end. The secondary blade portion defines a secondary concave surface configured to generate a torque about the rotational shaft.

A drag-based wind turbine device is disclosed. The device is an improved wind turbine comprised of two sets of stacked and coupled, drag-based vertical axis wind turbines, wherein drag from the first turbine helps propel the second turbine. Additionally, the surface of the first turbine is convex to ensure wind is always deflected toward the second turbine, wherein the wind is then received by the concave side of the second turbine. Further, the blades are arranged in a horizontal and sloping manner. In the convex position, each slope blade deflects incoming wind to the other set of turbines in a concave direction. Additionally, the gap between two turbines can be adjusted for different wind/current speeds, viscosities, compressibility, and densities for the best efficiency.

EnergyMaster is an innovative floating hybrid tidal/wave/wind energy harvesting system based on vertical axis turbines for synergized tidal, wave and wind energy production in agriculture and aquaculture applications. EnergyMaster can continuously, and simultaneously, harvest wind and tidal energy in a wide range of wind and tidal current speeds, while providing excellent self-starting capability.

A linear network of wind turbine blade arrays has a plurality of wind turbine blade arrays. Each of the wind turbine blade arrays has a frame with a top structure and a bottom structure. The top structure is spaced from the bottom structure with first and second opposite vertical side structures. The top structure includes a top enclosure and the bottom structure includes a bottom enclosure. A plurality of shafts are spaced apart from one another along and extending between the top structure and the bottom structure. Each shaft is configured to rotate about a respective shaft axis within the frame. A blade formation for each shaft is arranged and configured to interact with moving air to cause rotation movement of the respective shaft. At least one generator is operatively connected to at least one shaft. The generator is mounted in one of the top enclosure and bottom enclosure.

A wind power generation device includes rotary blades that each includes a front blade surface parallel to the rotation axis and curved to protrude frontward, and a rear blade surface, being parallel to the rotation axis, curved so as to be concave frontward, and having a smaller curve depth than the front blade surface. The front blade surface includes a first curved surface far from the rotation axis and formed frontward from an outer end, and a second curved surface close to the rotation axis and formed rearward from a crest to connect to an inner end, a surface length thereof being smaller than that of the first curved surface. The first curved surface has recesses at positions closer to the outer end than to the crest of the front blade surface. Thus, the rotary blade rotates by receiving a fluid and can improve rotation efficiency.