Any windmill impact from changing wind patterns or reducing wind power is radically less than eg building homes (given we build millions of homes annually), or simply driving vehicles (of any sort, given the numbers of vehicles globally).
You could never build enough windmills to cause a problem. The only real environmental concerns are killing animals (insects?), and construction / manufacturing related.
Any windmill impact from changing wind patterns or reducing wind power is radically less than eg building homes (given we build millions of homes annually), or simply driving vehicles (of any sort, given the numbers of vehicles globally).
You could never build enough windmills to cause a problem. The only real environmental concerns are killing animals (insects?), and construction / manufacturing related.