The big problem is dissipation of energy. There was a recent study claiming this but I don’t have it handy to quote. Doesn’t matter, I’ve said the same thing for years.
It’s obvious, especially so on wind farms.
Basically as the wind spins the blades on the windmills it absorbs energy from the wind. That can have effects downwind of the farm.
The wind now has less potential energy and that can cause warming, cooling, less rainfall and other unintended and unforseen results.
It alters the weather downwind possibly and probably with devastating effects.
Windmills near Tehachapi, CA interfere with the radar from Edwards AFB, causing problems with Edwards’ research.