ebay contact no Until recently the commercial use of wave power has been limited to small systems of tens to hundreds of watts aboard generate power. As the buoy heaves up and down in waves, the oscillating water column (OWC) in the centre pipe of the buoy's hull acts like a piston, alternately pushing air out the top of the pipe and drawing it in. This pneumatic power can be converted directly to sound through a foghorn, or indirectly to light by spinning a turbine-generator, which charges an electrical storage battery. Although the relentless energy of marine currents has been obvious from the earliest days of seafaring, it is only now that the development of modern offshore engineering capabilities coinciding with the need to find large new renewable energy resources makes this a technically feasible and economically viable possibility.