I have noted that small commercial machines all seem to be optimized for high winds, which occur infrequently.  The larger the commercial machine, the more it seems to be designed to produce in 'normal' winds.  As an economy of scale, it may be more likely to implement pitch control, electronics, and more thorough design to increase efficiency as well.  If you are connected to the grid, the small machine optimization may make some sense in that the power output is so much larger during those rare times of high wind.  For charging batteries however, you'll be left in the dark once your batteries go dead the rest of the time.  For battery charging I think DanB has it right to size it and optimize it for low (normal) winds, and basically build it to survive the high ones.  It may be a little easier to obtain higher efficiency in a larger machine, but I can not think of a rule of physics that requires it to be that way.  I haven't read Paul's arguments on the subject so I am uncertain what his reasonings are.  He is generally very well regarded, so I am sure there is a logical basis.  Rich Hagen
'A Joule saved is a Joule made'
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