Wind power faces difficult obstacles, but its supporters can at least point to wind farms already in operation. By contrast, tidal power, often touted as an environmentally friendly alternative, has struggled. A firm quoted on London’s Alternative Investment Market believes it is on to the next big thing in carbon-neutral energy - wave power. Ocean Power Technologies (OPT) is one of four companies whose hardware is to be tried out in a wave-power project off the coast of Cornwall. Electricity should start coming ashore in 2010. Over several decades, a range of technologies have been used to capture wave power. The Cornwall project, called Wavehub, will experiment with four approaches. One involves a floating platform in which waves push air through turbines. A second exploits tidal flow rather than waves. The third system - from Scotland’s Pelamis - uses a series of floating tubes joined by hinges: as they move relative to one another, power is generated. Then there is OPT’s system. It consists of a steel column that sits vertically in the water. A collar like a huge doughnut moves up and down the column as waves pass. That movement drives a generator and […]