.... I was thinking a simple DC battery system and some lights or something would be pretty easy, but I would really love to get this thing backfeeding my grid power so that I could save some money on my power bill....
Very nice yard sale find. I think you have an Air X wind turbine, missing the aluminum hub and carbon fiber blades.
That one should be about 46"-60" in diameter, depending on the model, with a max output of about 400-500 Watts.
Take a peek at
http://www.reuk.co.uk/Air-X-Wind-Turbine.htmand Google on from there.
I recommend you get the exploded parts diagram from the manufacturer and consider buying the missing parts. It would probably be a real pain to try to fake them up and would cost far more than just buying the parts.
(Check eBay: I think a set of blades runs around $50.00.)
Chances are it's missing the blades because a falling tree branch went through them, or the tower it was on fell over.
This is a small turbine. It would cost you at least $6,000.00, and maybe as much as $10,000.00 to hook it up to the grid. That would be a complete waste of time and effort for a machine that will, on the average, probably put out 100 Watts.
You could save more money just by turning off an unneeded light or two.
This turbine, if it can be put back in service, would be great for a hunting cabin or sailboat. It can trickle-charge a battery bank, run a small radio, and give you enough light to read a book by. That's about it.
But it's a GREAT place to start if you are interested in wind energy, etc. So play with it, but don't expect commercial power production.
It's just a puppy.