FAQ: Wind Generators

The potential noise is a value judgement and seems to be a function of the number of blades, blade size, mass, and aerodynamic design.   The noise, such as it is, comes from (a) rotational vibration and (b) "wind in the rigging" as it passes through the blades.  

The Air Marine unit is a superbly designed unit delivering significant  power, very efficiently, from a very light 45 inch three bladed propeller.   The blades are of small cross section and their design is
the core reason for Air Marine's success.   Besides it looks neat! 

Other units swing relatively heavy blades over a much larger area and some designs have all the sophistication of a coal shovel.   A friend has a Wind Bugger; a cheap and nasty two bladed unit of limited power rigged in the fore triangle when not sailing.   The considerable vibration is somewhat damped by the halyard from which it hangs but the wind noise is a real factor; but still less than the diesel!   One positive factor is that you will always know when the wind pipes up in the middle of the night!

The other issue to consider is that the Air Marine unit is self limiting in high winds by its blade design, that is it will not overspeed.  The unit can also be stopped simply by switching the output to ground.  Any other units I have seen require shaft brakes and/or physical constraints.   In high winds some, like the Wind Bugger, take on all the neat characteristics of an enthusiastic helicopter with a mind of its own.

For my money the solid installation of an Air Marine unit aft on a pole  is worth every cent and I can always rationalize any wind generator noise by considering the alternatives.   My margarita blender, microwave and wife's hair dryer make noise because of it!   (Gary Wiseman)