Spinning sail technology is poised to bring back wind-powered ships

Over 200 years after steamships first began crossing the ocean, wind power is finding its way back into seafaring. Global shipping firm Maersk is planning to fit spinning "rotor sails" to one of its oil tankers as a way of reducing its fuel costs and carbon emissions. The company behind the technology, Finnish firm Norsepower, says this is the first retrofit installation of a wind-powered energy system on a tanker.