Abstract: A dual-point absorber includes a first buoy, a second buoy, and a power take-off. The first buoy of the dual-point absorber is connected to a linkage. The second buoy of the dual-point absorber is capable of a movement relative to the first buoy. The power take-off is coupled to the first buoy and the second buoy. The linkage can be used to reduce a heave movement of the first buoy that is caused by waves.

Abstract: A system includes a fuel burner disposed within a buoy, and at least one fuel tank coupled to the fuel burner. The fuel tank preferably contains ethanol or propane. The system comprises either a thermoelectric generator or an electrical generator mechanically coupled to a heat engine. The ethanol or propane is burned to generate electric power. At least a portion of the electric power that is generated is stored in a battery system so that the system can provide peak levels of electric power consumption that are relatively large. The system can be used in autonomous marine applications.

Abstract: A buffered power transfer apparatus includes rechargeable batteries. The buffered power transfer apparatus is used on demand to convert high voltage DC to low voltage DC at maximum efficiency with minimum standby losses. The buffered power transfer apparatus may be used in a Wave Energy Converter.

Abstract: A power-take-off system for use in a wave energy converter buoy employs a meshing nut and screw shaft assembly for motion conversion. That is, the motion of the buoy float is coupled to drive the nut along the screw shaft on which it is mounted. The linear movement of the nut along the shaft causes the shaft to rotate and this rotational motion is then coupled to rotate an electrical generator.

Abstract: An electric generator driven by a source of variable energy produces at its output an alternating current (AC) output voltage and current which is converted via controllable active switching circuitry into a direct current (DC) voltage which is stored in an energy storage element. Power losses are associated with the active switching circuit and the AC to DC conversion. The power available at the output of the generator can be determined. If the available power is less than the power losses the controllable switching circuitry is disabled.

Abstract: A wave energy converter (WEC) buoy includes at least one pitch-driven WEC (“PDWEC”) device. Each PDWEC device includes two reaction masses which are placed at diametrically opposite ends of a container designed to float along the surface of a body of water and to move in response to the pitching motion of the waves. The reaction masses are interconnected so that when one reaction mass moves up, the diametrically opposed reaction mass moves down, and vice-versa. The movement of the reaction masses drives power take off (PTO) devices to produce useful energy. The reaction masses may be interconnected by any suitable linking system. One or more PDWEC device may be combined with a heave responsive device to produce a WEC buoy which can produce a power output in response to pitch or heave motion.

Abstract: A mooring system for a plurality of wave energy converters (WECs) includes a multiplicity of anchors coupled to form an array of contiguous hexagonal shaped cells. Each cell has 3 WECs and 3 anchors located at the vertices of the hexagon, with a WEC alternating with an anchor going around the perimeter of the cell. Except for the cells at the edges of the array, each WEC is connected to two anchors of its cell and an anchor of an adjacent contiguous cell. Each WEC is connected to three different anchors via 3 mooring lines spaced 120 degrees apart about the WEC. The ratio of the number of anchors per WEC is decreased by connecting each anchor to more than one WEC. The cells can be arranged to form many different patterns. In one embodiment a plurality of WECs and anchors are deployed in a generally triangular formation extending from an apex of the triangular formation to a base.

Abstract: The generally up and down movement of a reaction mass is converted into rotary motion which is used to drive a rotary hydraulic spring comprised of a rotary hydraulic pump motor and an accumulator to produce a “spring” function. The invention is particularly applicable to wave energy converters (WECs) having a reaction mass which needs to be coupled to a spring to ensure its oscillation and to cause it to be centered about its center of travel. The linear up-down motion of a reaction mass may be converted via a linear-to-rotary translator to rotary motion to drive a rotary hydraulic pump/motor so as to provide spring action to the reaction mass and ensure its oscillation and proper positioning.

Abstract: A wave energy converter (WEC) having an asymmetrically shaped float and a spar which move relative to each other in response to the waves. The asymmetrical float has one side longer than the other. A power take off device (PTO) is coupled between the asymmetric float and the spar for converting their relative motion into useful power. Apparatus is coupled to the WEC for: (a) orienting and rotating the longer side of the float to face and receive oncoming waves to increase energy capture when the waves have an amplitude below a predetermined value for improving the power generation of the WEC; and (b) rotating the float to orient the narrower side of the float to face and receive the incoming waves when the waves have an amplitude above a predetermined value, so as to reduce the forces to which the WEC is subjected. There is no known WEC system with an asymmetrical float which is raised and lowered by the waves.

Abstract: Apparatus for connecting a power cable to a marine vessel which is subject to pitch, heave, roll and yaw motion includes a ball and socket device for decreasing the twisting and bending of the power cable. The socket is attached to the vessel and the ball can rotate freely Within the socket but its up down motion is restricted. The power cable's outer protective sheath is attached to the ball while its conductors pass through the ball and are connected to an internal connector. A flexible cable (wire) is connected between the internal connector and electrical equipment internal to the marine vessel.

Abstract: A reaction mass and a spring are configured to form an “oscillator”. The reaction mass is coupled to, and can wrap around, a first pulley via a first belt/cable. The spring is coupled to, and can wrap around, a second pulley via a second belt/cable. The first and second pulleys are mechanically linked together and are mounted so they rotate in tandem. The diameter of the second pulley is different than the diameter of the first pulley to cause the reaction mass to travel a different distance than the spring in response to the up down motion of the reaction mass. The first and second pulleys may be circular with the second pulley being made smaller than first. Alternatively, the first pulley may be circular and the second pulley a cam of varying radius.

Abstract: A wave energy converter (WEC) system includes WEC devices which can function to produce useful energy (power) efficiently in response to heave motion and/or pitch motion and/or roll motion. Pitch responsive devices are deployed around the outer periphery of a container and one (or more) heave responsive device is located about the center of the container. The pitch responsive devices may be of the type defined as PDWECs which include two reaction masses which are primarily operable in response to pitching motion or they may be of the type which includes one reaction mass operable in response to pitch and/or heave motion.

Abstract: A wave energy converter (WEC) system includes first and second bodies which can move relative to each other in response to waves and a power-take-off (PTO) device coupled between the two bodies to convert their relative motion into energy. A sensor is used to sense selected characteristics of an incoming wave and produce signals which are applied to a control computer for predicting the impact of the incoming waves on the WEC. Simultaneously, signals indicative of the actual conditions (e.g. the velocity) of the WEC are also supplied to the control computer which is programmed to process the predicted and actual information in order to generate appropriate signals (forces) to the components of the WEC such that the average wave power captured by the PTO is maximized.

Abstract: A wave energy converter (WEC) includes a float tending to move in phase with the waves, a spar tending to move out of phase with the float and power take off device (PTO) coupled between the float and spar for converting their relative motion into useful energy. The PTO includes a rack and pinion mechanism which drives a high-torque, multi-pole, permanent magnet generator (PMG) to produce electrical signals of relatively high frequency relative to the frequency of the waves and the basic motion of the rack and pinion mechanism. In accordance with one aspect of the invention, the rack and pinion mechanism may be located within the spar which may be hermetically sealed by a sealing mechanism which allows a thrust rod coupled between the float and spar to move up and down with little friction to ensure efficient operation. In addition, a braking arrangement is provided for inhibiting relative motion between the float and spar during extreme severe wave conditions.

Abstract: A wave energy converter (WEC) includes a float and a spar for guiding the up and down movement of the float in response to the waves. A power take off (PTO) device coupled between the float and the spar and mounted within one of the float and spar such that the PTO includes apparatus responsive to the mechanical interaction of the float with the portion of the spar in proximity to the float for converting their relative motion into useful energy. In one embodiment the PTO includes a linear rack extending along an external portion of the spar and a linear to rotary converter, mounted within the float, including a double sided toothed belt for engaging the rack and causing rotation of the rotary converter to drive an electric generator. In another embodiment the PTO includes tires mounted within the float which rotate as the float moves up and down. In another embodiment the PTO includes a rack and pinion arrangement with one of them connected to the spar and the other mounted in the float.

Abstract: A float structure for a WEC is designed to have a tapered underside to reduce the impact due to wave slam and bending moments while providing little reduction in the surface area responding to the wave surface in order to maintain the beneficial power generating capability of a “flat” float. The underside of the float presents an inverted wedge section to decrease loads associated with wave slamming. The float may have a generally toroidal or elliptical configuration at and about the “still” water line with the generally submerged underside of the float having a cross section shaped to have one or more inverted triangular sections extending between the outer perimeter of the float and its center to reduce impact loading due to wave slamming while maintaining power producing capability.

Abstract: A wave energy converter (WEC) includes a float which moves generally in phase with the waves and whose up and down motion is guided by and along a spar having an upper portion and a lower portion. A power take off (PTO) device is coupled between the float and the spar for converting their relative motion into useful energy. In some embodiments, the PTO includes (a) a drum having an axis of rotation rotatably mounted within one of the float and spar; and (b) cabling means connected between the drum and the other one of the float and spar for causing the drum to rotate as a function of the up and down motion of the float. In other embodiments, the PTO system is formed using a pre-tensioned roller chain wound around sprocket wheels located within one of the spar and float with the opposite ends of the chain connected to the other one of the spar and float to cause rotation of the sprocket wheels in response to movement of the float relative to the spar.

Abstract: For protecting surface floating wave energy converters (WEC's) against surface turbulence, the WEC's are removed from the water surface. For reducing the force required, the WEC's include a hollow member having an apertured outer wall. In the case where the WEC is to be lifted out of the water, the hollow member is normally submerged and full of water, and, during its lifting, water drains through the wall apertures thereby reducing the weight of the member and reducing the force required to lift it. In the case where the WEC is to be submerged, the hollow member is normally empty of water but fills with water through the wall apertures as the member is pulled beneath the surface. The weight of the water reduces the force required to submerge the member.

Abstract: For reducing the number of anchors required for mooring a plurality of WECs in a body of water, the WECs are arrayed in two patterns enabling the sharing of anchors among the WECs. One pattern comprises pluralities of WECs disposed in polygonal shaped cells with an anchor disposed beneath each cell connected to all the WECs in the cell. A second pattern comprises a tessellated pattern of contiguous cells with WECs at the interface between contiguous pairs of cells being common to both cells of the pairs.

Abstract: A wave energy converter (WEC) system includes a shell containing an internal oscillator comprised of a reaction mass suspended from the shell by an elastic spring in parallel with a constant force spring. The constant force spring provides a relatively constant force (Fc) to counterbalance the static weight of the reaction mass and reduce the extension “static” length of the elastic spring while the elastic spring exerts a force (Fes) on the reaction mass that is proportional to the displacement, x, of the elastic spring. A power take-off (PTO) device, located within the shell, coupled between the shell and the internal oscillator converts their relative motion into electrical energy.