Hi Ray, I can't answer your question but I just wanted to say that this is one of the most unique model projects I've seen in a long while. Are you attempting to actually produce "scale" power with it? or is the generator part of an animated scene?
My only experience with generators is with diesel and gas powered units. Diesel and multi-cylinder gas generators run at 1800 RPMS to produce 240 VAC @ 60 cycles. Single cylinder gas powered units run at 3600 RPMS to produce the same. The wattage output is determined by the physical size and number of windings being driven within a magnetic field and the horsepower of the driving engine. Wind generators may have some type of gearing arrangement to step up the RPMS which could account for the huge size of the blades to produce the torque that would be required.
Just some quick math...3600RPMS X 1/87 = 42 RPMS or at 1800 RPMS = 21RPMS. So it seems to me that if your generator is just an animation you're pretty close to a scale speed in HO so if you could reduce that by say another 25% you would be close in N scale. IMHO I'd just run it at a speed that looked realistic to me.
Dang! All I wanted to do was compliment you on your project and got off into space!!!!
I think its a great idea!