The concept of a wave energy converter system is capturing ocean wave energy and converting the kinetic energy from the waves acting on the device and the gravity of the device into electricity. The technologies advantage or disadvantage can easily be compared by the way they capture the kinetic energy such as percent of body captures wave energy, how it energy converted to electricity, how they can be installed and how to implemented.
StingRay Wave energy Converter
Columbia Power Technologies, an Oregon-based wave energy developer, has designed a wave power system that captures energy from passing waves and produces electricity on-board the device. Columbia Power’s StingRAY wave power system uses the floats and spar that independently react to the shape of the passing ocean wave. Each float is directly coupled by a drive shaft to its own rotary generator. The two generators are located inside the nacelle near the top of the vertical spars. As each float rotates, so does its generator, which creates electricity.
Oyster Wave Energy Converter
The Oyster is a hydro-electric wave energy device that uses the motion of ocean waves to generate electricity. It is made up of a Power Connector Frame , which is bolted to the seabed, and a Power Capture Unit. The PCU is a hinged buoyant flap that moves back and forth with movement of the waves. The movement of the flap drives two hydraulic pistons that feed high-pressured water to an onshore hydro-electric turbine, which drives a generator to make electricity. Oyster is stationed at the European Marine Energy Centre at its Billia Croo site in Orkney, Scotland.
Ocean Power Technologies (O.P.T.)
Ocean Power Technologies (O.P.T.) is a US owned renewable energy company, providing power generating devices, services and related equipment for the extraction of energy from ocean waves. The Power Buoy consists of a float, a spar, and a heave plate as shown in the schematic to the left. The float moves up and down the spar in response to the wave motions. The heave plate maintains the spar in a relative stationary position. The relative motion of the float with respect to the spar drives a mechanical system contained in the spar to converts the linear motion of the float into a rotary one. The rotary motion drives electrical generators to produce electricity for the payload or for export to nearby marine applications using a submarine electrical cable. Projects are now underway around the world.
Azura Wave Energy Converter
Azura extracts power from both the heave (vertical) and surge (horizontal) motions of waves to maximize energy capture. The system produces power as a result of the relative rotational motion between the hull and the float. The power takeoff (PTO) system is based on high pressure hydraulics and is located within the Power Pod.
Pelamis Wave Power
The Pelamis machine is an offshore wave energy converter, operating in water depths greater than 50m. The machine consists of a series of semi-submerged cylindrical sections linked by hinged joints. As waves pass along the length of the machine, the sections move relative to one another. The wave-induced motion of the sections is resisted by the hydraulic cylinders which pump high pressure oil through the hydraulic motors via smoothing hydraulic accumulators. The hydraulic motors drive electrical generators to produce electricity. Electricity from all the joints is fed down a single umbilical cable to a junction on the sea bed. Several devices can be connected and linked to the shore through a single seabed cable Pelamis Wave Power.