A kinetic fluid energy conversion system comprises one or more hubs which rotate about a central hub carrier, each including one or more independently controlled articulating energy conversion plates (ECP). An articulation control system rotates each ECP independently of all others to control its orientation with respect to the fluid flow direction between an orientation of 90 perpendicular to the fluid flow, while traveling in the direction of the flow and 0 minimal drag parallel position to the flow, while traveling in the direction against the flow or blocked from it. Each hub can be operably coupled to another hub to form one or more counter-rotating hub and ECP assemblies whereby the mechanical energy is transferred through the hubs, to one or more clutch/gearbox/generator/pump assemblies thereby permitting such assemblies to be land-based when the system is air-powered, and above or near the surface, when the system is water-powered.

A kinetic fluid energy conversion system comprises one or more hubs which rotate about a central hub carrier, each including one or more independently controlled articulating energy conversion plates (ECP). An articulation control system rotates each ECP independently of all others to control its orientation with respect to the fluid flow direction between an orientation of 90 perpendicular to the fluid flow, while traveling in the direction of the flow and 0 minimal drag parallel position to the flow, while traveling in the direction against the flow or blocked from it. Each hub can be operably coupled to another hub to form one or more counter-rotating hub and ECP assemblies whereby the mechanical energy is transferred through the hubs, to one or more clutch/gearbox/generator/pump assemblies thereby permitting such assemblies to be land-based when the system is air-powered, and above or near the surface, when the system is water-powered.

A pitch control system characterized by a hub with at least two blade housings on the hub that are disposed around the hub axis. The blade housings have corresponding blades that engage with them. The blades spiral along housing longitudinal axes toward and away from the hub axis about a segment of helical path to effect a change in the pitch of each blade. One or more elastic members draw the blades toward the hub axis, either directly or indirectly. There are pitch mechanisms effective to facilitate blades to spiral around housing-longitudinal axes. A blade will spiral away from the hub axis when the centrifugal force exerted on the blade exceeds the opposing elastic force in the housing-longitudinal direction (neglecting other forces). Conversely, blades spiral toward the hub axis when said centrifugal force is less than said elastic force. There is an imaginary plane orthogonal to the hub axis. Housing-longitudinal axes have angles with respect to the imaginary plane of not more than 30 degrees.

A kinetic fluid energy conversion system comprises one or more hubs which rotate about a central hub carrier, each including one or more independently controlled articulating energy conversion plates (ECP). An articulation control system rotates each ECP independently of all others to control its orientation with respect to the fluid flow direction between an orientation of 90 perpendicular to the fluid flow, while traveling in the direction of the flow and 0 minimal drag parallel position to the flow, while traveling in the direction against the flow or blocked from it. Each hub can be operably coupled to another hub to form one or more counter-rotating hub and ECP assemblies whereby the mechanical energy is transferred through the hubs, to one or more clutch/gearbox/generator/pump assemblies thereby permitting such assemblies to be land-based when the system is air-powered, and above or near the surface, when the system is water-powered.

A servo actuator is provided which may comprise a controller configured to control a plurality of solenoid valves based upon an output signal. The plurality of solenoid valves may be used to control the position of the object. For example, a set of solenoid valves, of the plurality of solenoid valves, may be configured to conduct fluid from a tank into a first chamber of the cylinder, conduct fluid from the tank into a second chamber of the cylinder, conduct fluid from the second chamber of the cylinder into a first solenoid valve and/or conduct fluid from the first chamber of the cylinder into the first solenoid valve. The first solenoid valve, of the plurality of solenoid valves, may be configured to conduct fluid from the set of solenoid valves into a vent valve based upon a pulse width modulation (PWM) signal received from the controller.

The invention relates to a method for operating a wind turbine. The method comprises measuring a torsion between a first point (10) of a rotor blade (100) of a wind turbine and a second point (12) spaced apart from the first point, and determining at least one parameter, in particular an actual value of the at least one parameter, of the wind turbine based on the measured torsion, wherein the at least one parameter is selected from the group comprising an angle of attack of the rotor blade (100), a pitch angle, a wind speed, an angle of incidence, and a flow speed.

A novel universal propeller has a gearwheel arranged on each rotor blade that is directly operatively connected to a reference gearwheel of a timing gear. The timing gear is operatively connected to a hub gear. The hub gear senses and processes an angular velocity ?.sub.n of a rotation of the hub. The reference gearwheel and the gearwheels of the rotor blades of the timing gear are configured that the ratio of an angular velocity ?.sub.r of the reference gearwheel to the angular velocity ?.sub.n of the rotational movement of the hub is as follows: ?.sub.r/?.sub.n=1?(?)*(S.sub.rot/S.sub.r), where S.sub.rot is a size of the gearwheels and S.sub.r is a size of the reference gearwheel. The present invention is particularly suitable for use in a wind power installation, hydropower installation or an engine of a ship or an aircraft.

A method is for exploiting the energy of a water current with an energy plant. The energy plant has at least one rope extending around at least two turning stations, and carries at least one at least partially submerged foil which is approximately symmetrical around its chord. The velocity and direction of flow of the water together with the moving speed and direction of the foil gives a resulting water velocity and direction acting on the foil. The method includes pivoting the foil until it has a desired angle of attack to the resulting water direction when the foil is being displaced co-currently; and pivoting the foil until it has a desired angle of attack to the resulting water direction when the foil is being displaced counter-currently, the angle of attack being the same or different co-currently and counter-currently.

The apparatus includes a wind turbine system for the collection of wind energy and the conversion thereof through staged-compression into highly compressed gas. The highly compressed gas is routed to a central tank, and then expanded into a plurality of concentric ring tanks, each storing gas at successively lower pressures. The cooling resulting from this expansion is utilized to cool hot compressed gas from an intermediate line of gas compressors, increasing the efficiency of the following compressors. This absorption of heat also improves the efficiency of the gas turbines driving electrical generators. The gas compressor in each wind turbine is located near ground level, and driven by a vertical shaft passing through the wind turbine support tower. One embodiment has conventional radially extending blades, and another embodiment has ducted blades to withstand higher winds. Both ground mounted and deep water adaptions for the wind turbines are disclosed.

A vertical axis wind turbine including a turbine rotor having an axis of rotation and at least one blade spaced from and mounted for rotation about the rotation axis of the turbine. The blade has at least one longitudinal surface substantially parallel to the rotation axis and for engagement, in use, with wind incident on the turbine rotor. The blade is a two part blade with a first leading blade portion pivotably connected to a second trailing blade portion. The turbine includes pitch control means and camber control means for controlling the pitch and camber of the blade.