Provided is a wave force utilization unit capable of further reducing product cost and installation cost and effectively utilizing a wave force while decreasing the wave force, and a wave force utilization system in which the unit is used. The wave force utilization unit includes a box-shaped floating unit 1 supported via a support to move in an up-down direction, in response to movement of the sea surface in the up-down direction. The floating unit 1 includes a main body 2, an introduction part 3 disposed continuously on one side of the main body 2, and a water drain part 4 disposed continuously on the other side of the main body 2, the main body 2 includes an air chamber 5 that is a sealed space and acts to float up the floating unit 1, and a flow-through chamber 6 through which seawater flows from the introduction part 3 to the water drain part 4.

The apparatus described is a buoyant energy converting apparatus for converting energy obtained from renewable ocean energy sources to useful energy, comprising: a wind energy converter; a buoyant platform arranged to support the wind energy converter in a body of water having a surface and a bed; and a connection member, the connection member being positioned between the wind energy converter and the buoyant platform, the buoyant platform comprises an in-use configuration in which the buoyant platform is submerged in the body of water. In the in-use configuration the connection member protrudes through the surface of the body of water such that the wind energy converter is located substantially above the body of water. The apparatus further comprises a wave energy converter. The apparatus aims to provide a device having increased stability in stormy conditions, a more consistent supply of power and improved cost and ease of maintenance.

A submergible wave energy converter and method for using the same are described. Such a wave energy converter may be used for deep water operations. In one embodiment, the wave energy converter apparatus comprises an absorber having a body with an upper surface and a bottom surface and at least one power take-off (PTO) unit coupled to the absorber and configured to displace movement of the absorber body relative to a reference, where the power take-off unit is operable to perform motion energy conversion based on displacement of the absorber body relative to the reference in response to wave excitation, and where the power take-off unit is operable to return the absorber body from a displaced position to a predefined equilibrium position and to provide a force acting on the absorber body for energy extraction.

Wave energy convertor (WEC) 100 and related control methods. The WEC has at least one cell 102 of variable volume containing an energy transfer fluid and at least partially bounded by a movable flexible membrane 106, and the at least one cell has a substantially constant membrane pressure differential during at least part of a respective cell volume deflation or inflation stroke. Pressure differential between the exterior and interior surfaces of the membrane of the respective cell can be maintained as stable and constant as possible for a substantial part of the volume change during deflation and inflation of the membrane/cell. Membrane and/or cell inclination angle can range between 35 and 50. Chord ratio of the flexible membrane of at least one cell can be between 1.01 and 1.3 during operation. A control surface 108 can modify the available membrane surface or limit of operation of the membrane for operation and/or modify an internal wall or surface of the cell.

Disclosed herein is a wave energy converter that uses a flexible and inflatable chamber to absorb wave energy and convert it to electrical energy through the varying hydrostatic and hydrodynamic pressure at or below the water surface.

Methods, system and devices 10 for capturing wave energy are disclosed. A submersible wave energy capture device 10 comprises a tube 12 and a plurality of one-way valves 21, 31, 41. The tube 12 has a seawater inlet 11 at an upstream end 10u of the tube 12. The downstream end 10d of the tube 12 is communicable with an energy utilisation means 2 powered by seawater flow from the tube 12. The one-way valves 21, 31, 41 divide the tube 12 into a series of chambers 20, 30, 40. The chambers comprises elastic walls 22, 32, 42. These are deformable so as to alter an effective internal volume of each respective chamber 20, 30, 40. The valves 21, 31, 41, open to permit water flow within the tube 12 in a downstream direction, and close to resist water flow within the tube 12 in an upstream direction.

A wave energy converter situated on a seabed includes a pair of pistons, a means for producing energy within a vessel, and a water-conveyance pipe attached to the vessel. The pistons reciprocate using differential pressure to extract energy from a wave transiting on the surface of a body of water. Water receiving ports at high and low pressure points create a differential pressure to act on the pistons and push them in opposite directions. A hydraulic cylinder or a linear alternator is attached between the pair of pistons to extract the energy.

Wave energy conversion systems (WECS) with internal power take-off mechanisms using internal inertias as well as WECS using a submerged water head for driving a turbine at a steady rate. The WECS involving internal inertias is effected through relative oscillation between masses inside the hull of watercraft excited by wave motion and whereby the masses' oscillations are captured by actuators (e.g., hydraulic) that pressurize a fluid or generate electricity. Different relative oscillation mechanisms are disclosed herein. The WECS involving a submerged water head involve the use of asymmetric floats, arranged in a circular orientation for omni-directional wave energy capturing, that drive respective pistons that pressurize the water head and drive the turbine. Alternatively, the use of articulating raft/barges or floats coupled via a lever arm can be used instead of the asymmetric floats for pressurizing the water head.

A closed system that captures energy derived from the head differential rather than open-water flows velocities while reducing potential environmental damages and costly maintenance due to bio-fouling. The continuously derived energy system utilizes an offshore bladder in communication with both a primary onshore bladder and a supplemental onshore bladder. Tidal energy is captured by turbines as fluid is transferred between the bladders. In addition, the system continuously extracts energy by diverting fluid to and from the supplemental onshore bladder during periods of near-high-ride and near-low-tide, during which the pressure differential between the offshore bladder and the primary onshore bladder becomes inefficient for energy production.

A submerged wave energy conversion apparatus and pressurized fluid or electricity production system are provided that harvests energy from a motive force derived from pressure differentials created by the interaction of the system with ocean water. The system is capable of capturing energy from up to six different modes of motion of the absorber body in response to the energy of incident waves. The apparatus has an absorber body that is attached to one or more damping mechanisms like a hydraulic cylinder, a hydraulic circuit that can create useful mechanical torque, a restoring mechanism such as an air spring to restore the absorber system to stable equilibrium, and a buoyant artificial floor to create an opposing reaction force. The apparatus may also have a controller for system monitoring and control, to maintain optimized energy extraction, and for load management to avoid damaging loads.