Now, Harvard has come to the same conclusion. In a report you won't find in the mainstream media, a Harvard study suggests that, yup, with regard to wind, the math does not add up. From CarpeDiem, here's the link.
“It’s clear the theoretical upper limit to wind power is huge, if you don’t care about the impacts of covering the whole world with wind turbines,” says Keith. “What’s not clear—and this is a topic for future research—is what the practical limit to wind power would be if you consider all of the real-world constraints. You’d have to assume that wind turbines need to be located relatively close to where people actually live and where there’s a fairly constant wind supply, and that they have to deal with environmental constraints. You can’t just put them everywhere.”
“The real punch line,” he adds, “is that if you can’t get much more than half a watt out, and you accept that you can’t put them everywhere, then you may start to reach a limit that matters.”But with enough tax credits, the future for wind farms is unlimited. Except in Europe.