I don't have any practical experience to fall back on. Also would two strands of smaller wire with the same number of windings be appropriate or is more better.
When I've wound my stators I've found that using two-in-hand windings doesn't change the cut-in appreciably. But it adds copper density so the magnetic flux lines are being cut by double the strands of wire. Think of it as running two generators in parallel with the same set of magnets. So the amount of amps it puts out increases, and the power curve is a bit steeper.
So for that reason, I wind less turns with two-in-hand generators vs single strand or your blades will reach stall too soon. It'll cut in a tiny bit later, but that's not significant because there's no good power in < 10 mph wind speeds anyway.
On 24 and 48 volt generators you don't have to worry about this as much as with 12 volt. A 10 foot machine with a 12 volt stator requires two-in-hand windings to my way of thinking. Once you go to 24 or 48 volt with a 10 foot you can easily get by with a single strand of AWG 13 in a 24 and AWG 14 in a 48.
So if you're building an OtherPower 12 volt, I don't know what the plans call for as far as windings, but if it's only single strand you can ask DanB what they wind them with using two-in-hand with their blade style to make it work.
And if you live in a gusty area like you describe I'd definitely wind it with heavy enough wire so that you can throw the shorting switch any time and shut it down without burning anything up.
The other thing is blade style. The OtherPower design uses a lightweight, high speed blade style that's easier to stop, so it's not as critical as when using a low rpm torque blade that will turn a shorted turbine at 250 rpm and reduce the whole thing into a molten glob of copper.
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Chris