Powering 100% of the grid through wind power is darned silly. Powering 2% or 5% of the grid through wind power can be economically viable. Windmills obviously have to be built where there's a lot of wind, and on a plains or even on pylons in the ocean. Solar power is currently not good for much more than powering a calculator. But with wind power, they've gotten it advanced technologically enough now that for relatively small amounts of power, you can do it economically. Best if you have a windy desert....
22,000 birds over 20 years isn't that many, probably as many as are killed by FedEx trucks or something.