[sourcesmith]

I am guessing vertical axis turbines do not have this bias but they only seem to be used in smaller designs?

[mannykannot]

I would guess that their awake is asymmetrical (though in a different way) and so there might be a favored way to arrange them, but as they are inefficient compared to conventional turbines, and because the blades undergo a large cyclic variations of wind load with each rotation, they are not cmpetitive for large-scale commercial use.