Can a small scale wind generator power enough batteries to power a 5 ton air conditioner? And if it can, how large of a battery bank would I need, and would a 220 power converter be good enough.
gee, kind'a hard to tell. is there any wind? how strong? all day? or just part of the day? what do you consider a small scale wind generator? does your AC use 110 or 220 power? (it might uses both. although 5 ton isn't all that large.) where are you going to put this? how are you going to anchor it? is it allowed where you live? are you going to have an alternate power source for when there is no wind? in which case, have you looked at what it takes to hook up to the power grid? maybe you ought to talk to someone around where you live about this.
While I'm not sure how much power your air conditioner will need (different units have differing efficiencies) but for a first approximation we might guess around 5KW. 5KW is on the larger side for residential wind turbines, but should be possible. Next problem is how much does the wind blow, if it is constant, or at least constant when you need air conditioning, then you don't need much of a battery bank. But you'd be lucky if that was the case, if you do need to store power for when the wind is low, then the turbine need to be sized to run the AC and charge the batteries, so an even bigger turbine will be needed. As you can see how much wind you have is a critical factor. A for size of battery bank, just to make the math easy I'll assume you need to store enough power to run the AC for 10 hours (this is just a wild guess, it might be far different) 5KW x 10 hours is 50,000 watt/hours, on Wikipedia I found a claim that typical energy density for lead acid batteries for this application is between 30 and 40WH ber kilogram, using the average, you'd need around 1400Kg (~3000lb) of batteries. There are really too many variables too give a good answer here, if you would have no problem spending $20,000 (and wouldn't totaly freakout over $50K+) then contact a local consultant for more information. If you can't afford that, it is probably not really worth giong any further since $20K is at the very bottom of the price range for that size of instalation.
