your bill auctually sounds about right,this is an expensive gig,the only thing i could say is maybe try to eliminate some of your fans,using a pasive intake exhaust from the room through the lights and out of the building whal fresh air is naturally drawn into the room.........some one sed use a generator trust me not a good idea, your going to be spending more in fuel than your power bill and you need 2 or 3 generators because most will fry if you try to use them for continues runs,unless you buy something huge made to power up buildings in case of power failure,wich run about 80-380 grand.