You misunderstand the numbers I cited. I factored in average wind conditions and average windmill production, downtime. Ge 1.5 mw wind turbines are 99 percent available meaning they are not down for maintenance more than 1 percent of the time.
I'd say that's pretty optimistic, based on my casual observation of the wind farm outside my town. The offline turbine count hovers pretty reliably around 10% every time I've checked. They are Suzlon units though, not GE.
Also, I don't think you counted transportation, installation or 20 years of maintenance costs in your numbers.