In my naive and unscientific way. I wonder if there is a law stating that for everything that has an upside there is an equal and opposite downside; applying said guessed-at law to wind power, obviously windmills can hurt the birdos; However if all the wind that blows round the world gives free energy, save for the capital and maintenance costs of windmills, .... could we, so to speak, use up the wind?(is at the heart of my question) Maybe the world needs winds and if we interfere with that might we do so at our peril? or am I being daft? it seems to me that wind power may break the upside/downside law, if such a law exists; - might it?