The tsunami in the Indian Ocean last December that killed nearly 300,000 people and shattered the lives of millions also offered the world an indelible demonstration of how much energy a wave can carry. Geologists estimate the underwater earthquake that triggered the tsunami unleashed a force greater than all the explosives detonated in World War II. That much energy—6 trillion watt-hours—breaks on the world's coastlines every two hours or so. Capture it all and you could power 5 million American households for a year.
Offshore, even more free energy rolls in swells. Tony Trapp, managing director of Engineering Business Ltd. in England, calculates that capturing just 1 to 2 percent of global wave power—the share he considers recoverable—could supply 13 percent of the world's current demand for electricity.