Japanese enter sail power arena

The project aims to substantially reduce fuel consumption by large merchant vessels, using large retractable sails, 20m wide by 50m high. The group has carried out simulations for routes such as Yokohama to Seattle; results indicate that hybrid ships with sails and engines could reduce annual fuel consumption by about 30% on average.

The sails are made from aluminium and reinforced plastic, rather than traditional fabric materials. The angle of each individual sail is controlled automatically, to obtain the maximum propulsive force. Each sail consists of five parts, so the sail can be retracted telescopically when the ship is at anchor or during rough weather conditions.

Computer simulations and model tests show that the concept works well in cross winds, so by choosing the optimal route based on wind strength and direction, rather then just the shortest route, it is said to be possible to travel faster and consume less fuel.

The cost of each sail is estimated at about $2.5 million, but at a fuel saving of 25% it should be possible to recoup the cost in 5-10 years. The next stage is to build a half-size prototype, which is expected to start sailing in 2016.