Where I live, there are several large windfarms, all built in the last ten years, within a half- to one hour's drive away. I have been within a few hundred yards of the turbines during a stiff wind, and have only heard a low-intensity hum, certainly nothing like the scream of a jet engine. I really don't think the monks should have too much to worry about, if the turbine design is carefully chosen. Ecological effects? Little more than the odd errant bird being dispatched by the blades, and even then, this is quite rare.