Small wind turbines have been used for years to provide electrical power for yachts, charging their batteries for their lights and other modest power requirements. These are highly effective, with new models coming along all the time. With everyone looking at the potential for wind as a clean source of power, and endeavouring to reduce the consumption of fuel, even commercial ship operators have been considering what contribution wind  power can make to the economics.
What is particularly attractive about wind generation of electricity is that a power-driven ship is rarely going to be in air so still that the wind turbine will not revolve. On a completely still day without a breath of wind, a ship steaming along at 18 knots will have an 18 knot wind flowing over it. The rest of the time the wind passing over the ship will depend upon the natural wind speed and its direction, but it will be rare that no wind is available to turn the blades of a turbine.
Experiments with even small wind turbines aboard large commercial craft have found that these devices can make some contribution to the ship’s electrical power requirements. It may not be a great deal, but it will be something, and will mean that the ship’s own generators will have to work slightly less hard. Multiply the number of turbines, increase them in size and even add to them a useful contribution from solar energy and there will be a perceptible reduction in the fuel consumption and generator load.
These power sources may be used to charge banks of lithium ion batteries. It is technology that has been used for some years, most notably in powering unmanned light vessels, where the solar arrays and wind turbines work together to provide enough power to drive a large rotating and long-range light.
New types of wind turbines that rotate on a vertical axis have proved to be stronger and just as efficient in a marine context, having been tested on exposed rock lighthouses in ferocious weather. Thus the ship of the future may derive electrical power from a whole range of sources, some traditional like diesel or shaft generators and some sustainable, with both wind and solar each providing their contribution. All these will aggregate into a more efficient, cleaner ship, which could conceivably supplement its conventional propulsive power with wind assistance.
As the price of fuel continues to rise and there is more pressure to reduce maritime emissions of all kinds, every sort of sustainable contribution will be welcomed. And if this process continues, newer, larger and more efficient wind generators may be seen as part of a ship’s power plant.
Source: BIMCO