Windfarms would certainly have less impact that any other source of energy I'm familiar with. Hydro dams adversely affect river ecology and are now much more expensive to develop. Nuclear power is still more expensive to develop, there is no long-term solution for storing the waste, and there is always the risk of a catastropic accident from operating the technology or from sabotage. No one is seriously considering new oil-fired plants. Natural gas plants are competitive now but still fill the air with greenhouse gas, and the price of natural gas is likely to escalate in the next decade. New coal-fired plants are cleaner than the older ones but produce even more greenhouse gases. Biomass generators are competitive but also spew out greenhouse gases. Solar arrays are still much more expensive than wind turbines.
What I'm not sure of is how costly windmill farms are to maintain. Some wind turbines have been abject failures in operation.