An axial impeller has a tubular housing mounted on bearings for rotation. The housing is capable of engaging a motor or generator directly or through a drive belt. Interior turbine blades are mounted on the housing wall. The blades may be hinged so they can rotate between a retracted position adjacent to the wall and an extended radial position. Rods penetrate the wall to position the blades between retracted and extended positions. When extended, the blades may be rotated to propel a fluid through the housing; and when retracted natural fluid flow is less restricted.

A kite for use in a system for extracting energy from the wind comprises: a wing (1) having a roll neutral point or zone when the kite is in flight; a tether (4) coupled directly or indirectly to the wing; a rigid spar arrangement (2); tensile couplings (3) from the spar arrangement to multiple locations on the wing; and an actuator linkage arrangement (6, 7, 10,11) having a length dimension that can be controllably adjusted. The spar arrangement has first and second attachments (8, 5) to the tether, at the first attachment (8) the spar arrangement is fixed to the tether at a location that is above a roll neutral point or zone of the wing, and at the second attachment (5) the spar arrangement is attached to the tether by the actuator arrangement (6, 7, 10, 11) at a location that is below the roll neutral point or zone of the wing.

A reciprocal motion wind energy harvesting device has a first vane carrier assembly and a second vane carrier assembly, which are supported by and rotate about a central shaft. The vane carrier assemblies support pluralities of vanes to receive wind force. The vanes are configured to be rotatable in order to produce opposing and reciprocating motion of the lever arm assemblies. The lever arm assemblies are operatively connected to a generator in order to convert the wind force received by the vanes into energy.

The invention is on the one hand a power generating apparatus exploiting wind energy, comprising a body (10), a main rotor unit (12) comprising a front rotating part being fitted with front blades being adjustable at an angle, and a rear rotating part being fitted with rear blades adjustable at an angle, said front rotating part and rear rotating part have rotation axes aligned parallel to each other, preferably being coincident with each other, a blade adjustment unit being adapted for adjusting of the front blades and the rear blades to rotate in opposite directions, a cable (18) enabling kiting of the body (10), a generator unit adapted for generating electric power from rotation of the front rotating part and the rear rotating part, and a wire adapted for conducting electric power generated by the generator unit, and the main rotor unit (12) is arranged in an opening (11) of and coupled to the body (10), and the main rotor unit (12) comprises blades being turnable into a covering position covering at least partly the opening (11). On the other hand, the invention is a method for operating the power generating apparatus.

A kite comprises: a wing; upper and lower flaps located along at least a portion of an edge of the wing that forms the trailing edge of the wing when the wing is active; a controller configured to generate control signals; and an actuator arrangement configured to change orientations of the upper and lower flaps relative to the wing based on the control signals generated by the controller.

Windraider is a process and a machine for converting wind energy into electricity. The Windraider process is a previously undiscovered highly efficient process for converting kinetic wind energy into oscillating rotating mechanical energy. The Windraider machine provides a unusually robust and stable platform for effecting the Windraider process, and a series of mechanisms for improving its range of applicability and for efficiently converting its resulting oscillating rotating mechanical energy into electrical energy.

A vehicle-based airborne wind turbine system having an aerial wing, a plurality of rotors each having a plurality of rotatable blades positioned on the aerial wing, an electrically conductive tether secured to the aerial wing and secured to a ground station positioned on a vehicle, wherein the aerial wing is adapted to receive electrical power from the vehicle that is delivered to the aerial wing through the electrically conductive tether; wherein the aerial wing is adapted to operate in a flying mode to harness wind energy to provide a first pulling force through the tether to pull the vehicle; and wherein the aerial wing is also adapted to operate in a powered flying mode wherein the rotors may be powered so that the turbine blades serve as thrust-generating propellers to provide a second pulling force through the tether to pull the vehicle.

An electrical power generator includes a first part configured to be located in a fluid such that, when the fluid moves, it generates vortices in the fluid so that a lift force is generated on the first part, which produces an oscillating movement of the first part, which has an amplitude. The natural oscillation frequency of the first part may be adjusted to wind speed by way of magnets, which repel each other. Magnets may also be used to generate electrical currents in coils. The first part can have a diameter that increases with distance above the base of the generator.

Consistent kinetic energy is harvested from wind and from flowing water in streams, rivers and tidal flows using a translating large sail, foil or wing which is permitted to translate in one direction, followed by translating in the opposite direction while pushing or pulling a cable, rod, or tether which in turn turns a pulley, wheel or other device from which traditional sources of power can be generated. The pulley wheel can be used to generate electricity, create hydrogen from water by electrolysis, compress air for transmission or storage, charge batteries, or perform work such as pumping water, heating water, moving objects, etc.

The invention relates to a three-propeller counter-rotating wind turbine that needs a smaller installation area compared to conventional wind turbines that are currently in use for the generation of electrical energy by benefitting from wind power in windy environments, and that nevertheless has higher production capacity, as well as increased productivity, and that does not employ gears, and that has a direct drive mechanism.