Wind is not the worst form of alternative energy -- that probably has to go to corn ethanol. But it is close. The consistent experience of European countries that have more wind power than the US is that, because wind is so unreliable, hot backup fossil fuel generation capacity nearly equal to wind capacity needs to be maintained. This means that even when the wind is blowing, it is not reducing fossil fuel consumption in any meaningful way. In other words, billions are spent on wind but without any substitution of existing power sources. Its just pure wasted money.
Anyway, here is a recent study by an environmental group, no less, that found that Britain's wind generation plants are running well under the promised efficiency. That is, of course, when they are even operable and not just broken down. In the latter case, companies go for the quick bucks of up front subsidies, then find that the units are not worth the repair costs when they break.