Solar sails harness both wind and Sun

BBC : An Australian company, SolarSailor , has been developing high-tech sails that will use both the Sun and the wind to reduce ships’ dependence on fossil fuels. The giant sails are covered with solar panels, and the electricity generated is stored in a battery. The technology, which combines an electric motor and a combustion engine, is similar to that used in hybrid cars. Currently in use on several passenger ferries operating near Hong Kong, Shanghai, and Sydney, the solar-sail technology could be mounted on all types of vessels, including tankers, cruise liners, and private yachts. SolarSailor’s founder, Robert Dane, estimates that the giant sails could cut a ship’s annual fossil-fuel usage by almost 50%. Although the company has been operating for more than a decade and has yet to turn a profit, new fuel-efficiency regulations being introduced by the United Nations International Maritime Organization may increase demand for SolarSailor technology.