Sail powered ships

The sailing ship may be the most environmentally friendly form of transportation ever created by humans. The world's trade routes continue to follow the winds and currents that seamen who were essentially given free power for the duration of their voyage originally plotted. Naturally, ships were limited to the speed of the wind that propelled them.

To take advantage of the favorable winds and to avoid unfavorable winds, frequently convoluted paths between locations were needed. Ships, however, have operated in a more-or-less reliable manner for centuries while emitting no greenhouse gases other than those produced by people and animals. And they can now once more. Currently, being tested at sea are experimental wind and solar-powered vessels.

Currently, being developed are sails with wing-like shapes that, when directed vertically to the wind, provide what aviators refer to as "lift." The force moves the ship forward rather than lifting it into the air. Solar panels on one side of the sail enable the ship to recharge its batteries, which power the lighting, controls, and electrical equipment on board.

With a device resembling a huge kite called a skysail, another type of wind-powered ship, the ship can be propelled by the wind when the sail is spread out in front of it. Another uses sail that are bent to the masts and spars. By allowing wind power to supply up to 60% of what is required, the design minimizes the need for engines, regardless of what fuel source they use.