The invention relates to a system for energy storage and recovery, comprising: at least one compressed-air tank, at least one pressurized-water tank in communication with the compressed-air tank, at least one turbine in effective communication with the at least one pressurized-water tank, a generator for generating electrical energy, a high-pressure pump for pumping water from a water reservoir into the pressurized-water tank. According to one aspect of the invention, the turbine in effective communication with the at least one pressurized-water tank is a reaction turbine, which is connected in series with a constant pressure turbine in such a manner that a drive shaft of the reaction turbine is connected to a drive shaft of the constant pressure turbine and a drive shaft of the generator, and the constant pressure turbine is arranged between the reaction turbine and the generator, wherein the generator includes an interface for connection to a public power grid.

A method includes installing a first stage assembly including a first ring member and a first stage of rotor blades, the first ring member defining a first end and the first stage of rotor blades defining a second end; installing a second stage assembly including a second ring member and a second stage of rotor blades, the second ring member defining a first end and the second stage of rotor blades defining a second end, wherein installing the second stage assembly includes fitting the first end of the second ring member to the second end of the first stage of rotor blades to form a first attachment interface; and pressing the second stage assembly against the first stage assembly to fix the first attachment interface.

A turbine rotor assembly including a unitary body including at least one inlet for inlet of a fluid into the rotor assembly and a plurality of flow channels extending through the unitary body and terminating in an outlet portion, the at least one inlet in fluid communication with each of the plurality of flow channels.

A runner for a hydraulic turbine configured to reduce fish mortality. The runner includes a hub and a plurality of blades extending from the hub. Each blade includes a root connected to the hub and a tip opposite the root. Each blade further includes a leading edge opposite a trailing edge, and a ratio of a thickness of the leading edge to a diameter of the runner can range from about 0.06 to about 0.35. Further, each blade has a leading edge that is curved relative to a radial axis of the runner.

A Francis turbine runner including a shortened band length and a shortened blade length combined with a reversed runner blade leading edge having a junction of the leading edge with the band forerunning a junction of the leading edge with the crown in the rotational direction, and a bandless runner including a shortened periphery length and a shortened blade length combined with a reversed runner blade leading edge having a corner of the leading edge at the outer periphery of the runner that is in advance of where the leading edge joins the crown in the rotational direction. Additional feature includes an inverted trailing edge curvature design on the runner blade that further shortens the blade length.

The invention relates to a system for energy storage and recovery, comprising: at least one compressed-air tank, at least one pressurized-water tank in communication with the compressed-air tank, at least one turbine in effective communication with the at least one pressurized-water tank, a generator for generating electrical energy, a high-pressure pump for pumping water from a water reservoir into the pressurized-water tank. According to one aspect of the invention, the turbine in effective communication with the at least one pressurized-water tank is a reaction turbine, which is connected in series with a constant pressure turbine in such a manner that a drive shaft of the reaction turbine is connected to a drive shaft of the constant pressure turbine and a drive shaft of the generator, and the constant pressure turbine is arranged between the reaction turbine and the generator, wherein the generator includes an interface for connection to a public power grid.

The device consists of a vertical axis (1), one or more bearing rings (2), rotor (3), one or more pairs of catchers (4) made of light and strong material, flexible connections (5) and valves (6) with air intakes (7). The device can be applied to capture mechanical pressure and extract energy from fluid flows. Since its catchers are made of flexible and light material, it is characterized by a simple structure, light weight, and easy production and repair. Also, the device has a large working area, and reduces to a negligible small value the aerodynamic resistance during the reversible half-turn of the rotor, which further increases its efficiency.

Methods and apparatus for a modular hydrokinetic turbine. An apparatus includes modular vertically floating units tethered to shore with a generator residing above water and vertically oriented blades submerged in water to convert a latent kinetic energy of a moving waterway into electricity.

A turbine for an underwater power station includes a rotor drum having blades that for each revolution are moved in and out of the drum, where the two end-edges of each of the blades are arranged slidingly in a corresponding stabilizing, linear, radially-oriented grooves in a rotational plate that is oriented perpendicular to the rotational axle. This way, the ends of the blades are supported when exposed to water flow while being outside the drum.

By optimizing the degree to which water is accelerated through a venturi device, the amount of power that an energy device extracts from the ocean is maximized. Prior venturi-based wave energy devices have proven to be inefficient because of the relatively small amount of power that they generate relative to their size and cost. By optimizing the venturi effect created within the submerged venturi components of such devices, the speed of the water moving through the narrowest portions of such a devices is maximized with respect to the wave environments in which they operate, and a maximal amount of energy is extracted from the ocean. This optimization of a wave energy device's power is sufficient to render such devices cost effective. The method of extracting energy from the accelerated flow of water moving through such venturi devices is not limited, and many alternatives exist, each with its own potential benefits.