That is (a) a function of turbine height, not rotor diameter, which can (and is) increased independently, (b) it is a strong factor only on land - on water, in fact, the same type of turbines stand on typically lower towers (the lower limit is not even turbulence-related: it is a height for safe passage of smaller yachts).

_{*Lunatic*, n.
One whose delusions are out of fashion.}