For small scale it's actually useful as long as you have wind. Interestingly, even small cities don't allow residential wind power. Out in the counties though there's no such ban. I know several people who run their house mostly on wind.
A big liquor store out in the county tried to go wind - two 60-foot towers with good sized turbines mounted. After three years he could see it's never going to pay off. Lots of juice needed 24/7/365 for refrigeration there. So the application really does matter. It's not even close to viable on the large scale.