The present invention provides an independent wave energy power generation buoyancy tank based on a principle of liquid sloshing. A shape of the independent wave energy power generation buoyancy tank is an oblate spherical floating sphere, and crash pads are arranged along the middle direction and the circumferential direction of the buoyancy tank. A hatch cover is installed at the top of the independent wave energy power generation buoyancy tank, and a washer is arranged at the contact between the hatch cover and the floating sphere 9. A signal lamp is installed on the hatch cover. An anchoring ring and a cable socket are installed at a top side of the independent wave energy power generation buoyancy tank. Four sand injection and discharge valves are uniformly arranged on the upper part of the independent wave energy power generation buoyancy tank along the circumferential direction.

A wave energy converter is provided which includes a central body including a nacelle, the nacelle housing at least one power take off. The wave energy converter also includes a first float and a first float arm coupled to the nacelle on a first side, and a second float and a second float arm coupled to the nacelle on a second side. The first float is rotatably coupled to the nacelle, the first float and the first float arm forming a first body configured to rotate, where the first body is operatively coupled to the at least one power take off such that relative motion between the first body and the central body generates energy in the at least one power take off. In one embodiment, the central body has a low reserve buoyancy, where the reserve buoyancy of the central body is lower than the reserve buoyancy of either of the first float and the second float, to minimize a heave response of the central body relative to the first float to increase output of the wave energy converter. In one embodiment, the central body includes a yoke extending downwardly from the nacelle, a plurality of lines attached to the base of the yoke, and a heave plate attached to the lower terminus of each of the plurality of lines.

This disclosure is directed to hydrodynamic electric generators, including their structural design, methods of deployment, anchoring systems, drive systems and control systems. The system can be scaled from ones that can be hand carried to large, stationary devices that can generate up to and greater than 20 kw in a current of 3 knots. In a stationary system, the device can be anchored to an underwater floor by an anchoring device supported by four adjustable legs. These legs can eliminate the need for extensive mooring lines, providing the device with a small footprint that is non-hazardous to marine animals or vegetation. Individual components, such as rotors, generators and other mechanical components can be modularly installed for easy removal and servicing without having to disturb the entire system.

The system utilizes fluid pressure achieved by increasing depth as a primary component for generation of energy. The system operates by varying its depth through changes in buoyancy. The ballast changes are controlled by electronics powered by a battery charged by a generator driven by a hydraulic system. Rather than utilizing a motor driven pump to generate pressure in the hydraulic system, a piston-like cylinder is applied pressure by the change in hydrostatic pressure as depth increases and draws fluid back into the cylinder as pressure decreases. As the system sinks, outside pressure forces hydraulic fluid to power a generator that charges a battery and powers a pump to deballast. As the system rises, the lowering of ambient pressure, and other internal forces, causes the hydraulic fluid to return to its initial state, where once the ballast begins to take in fluid, the whole process will continue to repeat.

A point absorber wave energy converter is described. The converter uses a surface piercing float operably coupled to a water column tube extending downwardly from the surface piercing float, the tube being open at its bottom and being configured to accommodate a column of sea water therein. Air is trapped above that column within a plenum, the plenum being configured such that operably relative movement between the point absorber and the internal water column expands and compresses the trapped volume of air. That movement can be used to pump air through an open or a closed circuit power take off system. The open circuit power take-off system as described is suitable for other oscillating water column wave energy converters including both floating offshore and fixed shoreline installations.

A wave energy converter is provided which includes a central body including a nacelle, the nacelle housing at least one power take off. The wave energy converter also includes a first float and a first float arm coupled to the nacelle on a first side, and a second float and a second float arm coupled to the nacelle on a second side. The first float is rotatably coupled to the nacelle, the first float and the first float arm forming a first body configured to rotate, where the first body is operatively coupled to the at least one power take off such that relative motion between the first body and the central body generates energy in the at least one power take off. In one embodiment, the central body has a low reserve buoyancy, where the reserve buoyancy of the central body is lower than the reserve buoyancy of either of the first float and the second float, to minimize a heave response of the central body relative to the first float to increase output of the wave energy converter. In one embodiment, the central body includes a yoke extending downwardly from the nacelle, a plurality of lines attached to the base of the yoke, and a heave plate attached to the lower terminus of each of the plurality of lines.

A method of operating a downwind floating wind turbine comprising the downwind floating wind turbine floating in a body of water assuming mean heel angle within a range, the mean heel angle defined by a mean pitch angle of a central axis Y of a tower of the downwind floating wind turbine in a direction of wind; and the downwind floating wind turbine operating with a maximum rotor misalignment from a horizontal axis that is perpendicular to gravity while assuming the mean heel angle. The tower includes a turbine with a nacelle, hub and a plurality of blades extending from the hub, the plurality of blades configured to rotate about a rotor axis R, the rotor axis R having rotor tilt angle defined by an angle of rotor axis R relative to a perpendicular axis to the central axis Y.

In a general aspect, a system stores energy underwater. In some aspects, the system includes a base having a bottom side resting on an underwater floor and a top side that includes recessed surfaces. The system also includes domed walls extending from the top side of the base to form respective fluid chambers. Each of the fluid chambers includes an interior volume that is at least partially defined by one of the recessed surfaces and an interior surface of one of the domed walls. The system additionally includes a pump and a generator. The pump is configured to transport water from the fluid chambers toward an exterior environment of the system. The generator is configured to generate electrical energy in response to water flowing from the exterior environment toward the fluid chambers.

A buoyant energy generating housing apparatus submersed in fluid currents. The disclosed embodiments comprises rotary turbines that harvest the kinetic energy in the currents, and buoys that house equipment and provide buoyancy to support the system. Movements and rotations are restrained by multiple cables or tendons that are anchored on the seabed, in combination with the internal active ballast system in the buoys. Applications in currents with direction change are possible with the use of two-buoy embodiments, further assisted by the optional use of weathervanes.

Systems and methods disclosed herein provide a tidal power generator including a first container, a second container coupled to the first container, a frame pivotably coupled to the second container, a first valve, associated with the second container, configured to selectively control ingress of a first volume of a fluid into the second container, and a second valve, associated with the second container, configured to selectively control egress of a second volume of the fluid out of the second container.