Recently, Ocean Power Technologies, Inc. has announce d that it has deployed its first PowerBuoy® under contract with Iberdrola S.A., one of the world’s largest renewable energy companies. As noted by Iberdrola, the deployment of OPT’s PB40 PowerBuoy is the latest milestone toward the building of the world’s first commercial utility-scale wave power generation venture to supply approximately 1.39 MW of electricity into Spain’s electricity grid. The PB40, incorporating OPT’s patented wave power technology, is the first of what is expected to be a 10-PowerBuoy wave power station to be built out in a later phase of the project, and generating enough electricity to supply up to 2,500 homes annually.
Another clean-tech company that is developing technology to generate electricity from the energy from the ocean's waves, is AWS Ocean Energy. AWS stands for Archimedes Wave Swing, and their lead product is the award-winning Archimedes Waveswing™ wave energy converter. This is a cylinder shaped buoy, moored to the seabed. Passing waves move an air-filled upper casing against a lower fixed cylinder, with up and down movement converted into electricity.
As a wave crest approaches, the water pressure on the top of the cylinder increases and the upper part or 'floater' compresses the gas within the cylinder to balance the pressures. The reverse happens as the wave trough passes and the cylinder expands. The relative movement between the floater and the lower part or silo is converted to electricity by means of a hydraulic system and motor-generator set.