Really it boils down to math, you have to figure out how much energy you can produce in a day with the generator, then you have to decide how much you can store in batteries and how much energy you waste trying to convert it back to 120 volts. Most of the free energy stuff is around 12 volts so you have to convert to 120, you waste a lot of electric doing that, then you have to figure out the load you will use on a daily basis to decide if you will produce enough. Plus you have to have a safe place for the batteries because they do explode from time to time. I'm no expert but I have read up some on the subject. They make it sound easy on TV butif it was so easy everyone would be doing it. The best way would be to use a fast flowing river to turn a generator, like half way up a mountain, you'd have your best luck with it. That's my 2 cents.