Wave power

About: Wave power is a research topic. Over the lifetime, 2671 publications have been published within this topic receiving 41439 citations. The topic is also known as: wind wave energy & sea wave energy.

Nonbreaking Wave Forces on Multiresonant Oscillating Water Column Wave Power Caisson Breakwater

Abstract: Experimental measurements of in-line wave forces on a 1:50 scale model of an array of multiresonant oscillating water columns (MOWCs), a free-standing wave energy caisson, are reported. Wave forces on a vertical wall were measured and compared with Sainflou's and Goda's formulas, which serve as base for studying wave forces on an MOWC array. A range of hydrodynamic parameters with different damping of the OWC chamber and center-to-center (c/c) spacing were used. In general, the force on the MOWC caisson array is twice that of the vertical wall for maximum damping of the OWC chamber. Reduction of damping of the OWC air chamber reduces the force on the array of caissons by 35-60% of the force on a vertical wall. It is found that shoreward force magnitude is greater than seaward. For spacing of 2-3 times the harbor width, the OWC array acts like a perforated breakwater, experiencing 60% of wave forces on the vertical wall, while for a c/c spacing range of 4-5, it behaves like a vertical wall. Incorporation of an air pressure release by pass system for the OWC chamber is recommended, as this will reduce in-line wave forces on a caisson array to a range of about 35-40%. The nonlinear response of the OWC on wave forces warrants the use of a numerical model and further investigation.

Wave-power generating plant

Abstract: In said plant, retaining cables that are secured to a support device, constructed underwater, or on an underwater machine shop, are used to retain a hollow body in such a way that the latter can roll freely on the waves of the sea, and its upward movements are led by means of tension cables to units, located underwater, for dynamos for the generation of power, which movements cause the units to rotate (Fig. 1). When the hollow body descends, the tension cables are rewound tightly during idling onto their cable drums by counterweights. Since the hollow body which develops the power for generating current is supported by the water, it can, within the bounds of technical feasibility, be constructed with large dimensions, for example the size of a football pitch. In this case, the guying, the number and strength of the retaining cables, and of the tension cables, as well, must be appropriate for the purpose of withstanding bad weather, as well. The power generation is extremely low on occasions, and then once again extremely high, and can be led into the public power grid only given special precautions.

Method for operating a buoyant body of a wave power plant and a wave power plant

Abstract: Method for maneuvering a buoyant body (11) of a wave power converter (12), said wave power converter (12) including a mechanical-electric, mechanical-hydraulic or piezo-electric energy converter (16) which is arranged in the sea under the buoyant body (11), said buoyant body (11) and wave power converter (12) being connected by a wire (13), and which buoyant body (11) is provided with at least one ballast tank (22) for controlling the buoyancy of the buoyant body (11), where the method includes, by means of measuring equipment acquiring information regarding wire (13) tension, filling level/pressure in the ballast tank (22) and stroke of the energy converter (16), and based on this information controlling the buoyancy of the buoyant body (11) by supplying/discharging water/air to/from the ballast tank (22) while at the same time adjusting the tension of the wire (13) by operating a winch (24) arranged in the buoyant body (11). The object of this controlling is to lower or raise the buoyant body (11) without removing the wire tension, and to provide optimal strokes for the energy converter (16) in relation to the wave movements at the surface affecting the buoyant body (11). The invention also relates to a wave power plant for executing the method.