A float (1) suitable for use as a buoy or as a component for a wave-powered vehicle. The float (1) includes an upper member (12) whose height can be changed and/or which remained substantially vertical even when the float is in wave-bearing water. A low drag cable (2) suitable for use as a tether in a wave-powered vehicle has a streamlined cross-section and includes a tensile member (21) near the front of the cross-section, at least one non-load-bearing member (22) behind the tensile member, and a polymeric jacket (23). Wave-powered vehicles having a float (1), a submerged swimmer (3) and a tether (2) connecting the float and the swimmer, include a means for determining whether the tether is twisted; or a means (91) for untwisting the tether; or a pressure-sensitive connection (71, 72, 73) which can disconnect the tether when the vehicle is dragged downwards by entanglement with a whale; or a 2-axis universal joint securing the tether to the float or to the swimmer; or elastic elements which absorb snap loads created by the tether; or two or more of these.

A wave energy converter (1) has: a buoyant structure (2) which, in use, floats on water; a generator (18); a generator drive mechanism (38) on board the buoyant structure (2), the generator drive mechanism (38) having an rotational input drive shaft (20) and a rotational output drive shaft (36); a drive member (22) operably connected to the input drive shaft (20), the drive member (22) being moveable back and forth between a first position and a second position; a biasing arrangement (23, 26) for example a buoyant block acting on the drive member; and, a submerged element 4, 4′ which, in use, moves below the surface of the water out of phase with the buoyant structure (2), the drive member (22) being attached by a tether (28) to the submerged element (4). In use, when the buoyant structure (2) encounters a wave crest, the spacing between the buoyant structure (2) and the submerged element (4, 4′) increases and the drive member (22) is pulled towards the second position by the tether (28), and, when the buoyant structure (2) encounters a wave trough, the spacing between the buoyant structure (2) and the submerged element (4, 4′) decreases and the drive member (22) is urged towards the first position by the biasing arrangement (23, 26). The back and forth movement of the drive member (22) between the first and second positions causes the input drive shaft (20) to rotate and, thereby, causes the output drive shaft (36) to rotate. The submerged element (4, 4′) is preferably a heave plate. The invention also comprises a heave plate for a submerged, partly submerged or floating structure.

A device for producing energy includes an air-towed vessel, and at least one water current turbine linked to the vessel by at least one electric cable. The water current turbine is linked to the vessel by at least one mechanical linking cable to be towed by the vessel. The water current turbine is spaced apart from the vessel, which makes it possible to increase the diameter of the turbine and to reduce the interactions between the turbine and the vessel. Moreover, it is then possible to provide a plurality of water current turbines towed by the same vessel.

The present disclosure provides a renewable energy generator including a roly-poly toy- or capsule-shaped housing floating in the water, a main generator unit, frame(s) fixed internally of the housing at intervals, a main rotation shaft for linking the main generator unit rotatably to the frame(s), and a controller for operating the pendulum by driving the main motor, and controlling the main generator unit to generate an electrical energy profit by using the housing behaving due to the pendulum operation. The main generator unit includes an internal housing, a pendulum moving inside the internal housing, a pendulum rotation shaft vertically connected to the pendulum and fixed to the internal housing, a main motor for converting kinetic energy of the pendulum into electrical energy, and a gear unit linked to the pendulum rotation shaft and transmitting the kinetic energy of the pendulum to the main motor.

A buoyant hydrodynamic pump is disclosed that can float on a surface of a body of water over which waves tend to pass. The pump incorporates an open-bottomed tube with a constriction. The tube partially encloses a substantial volume of water with which the tube's constriction interacts, creating and/or amplifying oscillations therein in response to wave action. Wave-driven oscillations result in periodic upward ejections of portions of the water inside the tube that can be collected in a reservoir that is at least partially positioned above the mean water level of the body of water, or pressurized by compressed air or gas, or both. Water within such a reservoir may return to the body of water via a turbine, thereby generating electrical power (making the device a wave engine), or else the device's pumping action can be used for other purposes such as water circulation, propulsion, or cloud seeding.

A barge generator adapted to generate electrical power from surface currents of a body of water. The barge generator has a plurality of hull portions that form one or more tunnels along the length of the vessel. Hydrodynamic screws are received in the tunnels and coupled to an electrical generator such that water currents communicated through the tunnel impart rotational movement of the screw. A deployable curtain is extensible to funnel the currents towards the barge generator to increase the volume and velocity of water carried through the tunnel.

A power generation device is adapted to be driven by ocean currents, and includes a craft body unit, a plurality of blade units, a plurality of power generators, and a plurality of sails. The blade units are mounted on the craft body unit, and are adapted to extend into the sea and to be driven rotatably by the ocean currents. The power generators are mounted on the craft body unit and connected respectively to the blade units for converting a kinetic energy of the blade units into electrical energy. The sails are mounted on the craft body unit for capturing the wind to maintain a location of the craft body unit against drifting from a force of the ocean currents applied to the craft body unit.

An ocean iron fertilization (OIF) method and system for electrochemically controlled release of iron in an ocean to stimulate growth of phytoplankton to increase CO.sub.2 sequestration by the ocean. The system includes a cathode submerged or floating in the ocean; an iron or iron-producing anode submerged or floating in the ocean spaced apart from the cathode; and a power supply unit connected to the cathode and the anode. The power supply unit drives electric current between the cathode and the anode such the anode generates oxygen (O.sub.2) and ferrous iron through electrolysis to be released in the ocean, and the cathode produces hydrogen (H.sub.2) and hydroxide (OH—) species through an electrochemical reaction at the cathode.

A device for extracting energy from flowing fluid is provided. First and second buoyant lateral side members are provided. A fluid turbine is disposed between and below the lateral side members. At least one support extends from each side member to the turbine. At least one adjustable length support connects to the first and second side members, the at least one adjustable length support being adjustable between a minimum length and a maximum length. When a length of the adjustable length support adjusts toward the minimum length the first and second side members move closer together to thereby lower the turbine relative to the lateral side members. When the length of the at least one adjustable length support adjusts toward the maximum length the first and second side members move away from each other to thereby raise the turbine relative to the lateral side members.

According to an example aspect of the present invention, there is provided a system for harnessing energy from moving ice, the system comprising a first part configured to move into a first direction under pressure caused by moving ice at least until an ice compression strength is reached and to subsequently move into a second direction, and a second part configured to transform kinetic energy of a cyclic motion of the first part into electric energy.