A friend of mine has one on his off-grid garage/trailer thing, and decommissioning costs involve taking it down - about as much work as removing a large TV antenna - and perhaps hauling the batteries to a recycling facility. The wind turbine runs the lights, computer/network gear and sound system. Inefficient? I don't know how much wind energy is being wasted, but it works. I don't think he's touched it since he put it up almost a year ago.