The invention relates to an installation having at least one caisson positioned at a given depth in a marine environment, said caisson including a rigid tank in which an oscillating plate moves, said oscillating plate being adapted to oscillate in relation to a vertical axis depending on fluctuations in the height of the water column created by the swell perpendicular to the plate, said tank and plate defining a chamber. The installation is characterized in that the chamber is sealed by a flexible hermetic pouch which is filled with a gas and deforms according to the oscillations of the oscillating plate, the pressure of the gas inside the pouch being adjusted so as to compensate for all or part of the weight of the water column perpendicular to the plate in the absence of swell.

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.

The invention relates to a system for converting the of swell and/or of wave energy, including a network of water compression columns (1), each having: a lower end (110) to be dipped into a volume of water, the lower end (110) having an opening (111) for collecting water in the column (1), so as to form a chamber including a gas in an upper portion (120) of the column (1), a first non-return valve (4) in fluid communication from said column (1) to an overpressure chamber (2) shared by the columns, and a second non-return valve (5) in fluid communication from a low-pressure chamber (3) shared by the columns to said column (1), wherein the overpressure (2) and low-pressure (3) chambers are fluidly connected via a turbine (6) and the columns (1) of the network are arranged contiguously, and the network extends in at least two non-parallel directions.

A generator for converting mechanical energy or hydropower or wind energy into electrical energy is disclosed. The generator includes a first member and a second member in contact with the first member to generate triboelectric charges. The second member rolls against the first member to generate a flow of electrons between two electrodes. Another embodiment of the generator includes two electrodes, and a member in contact with the two electrodes to generate triboelectric charges. The member rolls against the electrodes to generate a flow of electrons between the two electrodes.

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.

A method for driving a transmission mechanism output power in response to an anticipated fluid-pressure gradient field is provided. The method includes sensing the change of direction of pressure gradient field at a desired location from the different area of the transmission mechanism within fluid. The method further includes constructing fluid-pressure gradient field based upon isolation-fluid apparatus or low-density fluid space installed on a transmission mechanism within fluid.

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.

An artificial reef to be anchored to the seabed comprises two or more juxtaposed conduits which are positioned in parallel with the direction of wave propagation. Both conduits include directrices. The upper conduit includes directrices which drive the flow of the wave's crest, and the lower conduit includes directrices which drive the water diverging from the apertures in the area under the wave's trough. The upper and lower conduits are hydraulically connected, each connection comprising a shut-down valve associated with a useful energy-generating unit.

A wave operated assembly (20) configured to be submerged in a body of water (12), the wave operated assembly (20) comprising a wave actuated member (24), a second portion and a piston assembly, pressure chamber (22) or spring coupled between the wave actuated member (24) and the second portion. The wave actuated member (24) and the fixed portion each define part of a first chamber (22) or volume comprising or configured to receive a fluid. A lower portion of the wave actuated member (24) at least partly defines a free surface (35) between the fluid within the first chamber (22) or volume and the body of water (12). The wave actuated member (24) is movable relative to the second portion. The piston assembly, pressure chamber (22) or spring is configured to apply a force on the wave actuated member (24) that works in opposition to a force on the wave actuated member (24) due to the fluid in the first chamber (22) or volume.

A wave energy converter generates power from a wave-induced separation of a positively buoyant flotation module and a submerged negatively buoyant mass, using a rotating pulley to drive a power-take-off system.