And to add to the anecdotal evidence...
A few years back I shot a round at a 3d archery shoot with a gentleman who worked for the Bonneville Power Administration. I questioned him about the relationship between the dams and the wind turbines. He told me that weather models have gotten so good at predicting when the wind would blow that they are able to, in essence, turn the dams off and turn the wind turbines on with great efficiency.
However, wind turbines are NOT a replacement for dams, they just compliment them.