I just found out that I have a huge flaw in my planned grow room. I plan on using an abandoned house to grow and I was just gong to run 100 ft extension cords underground from 2 15 amp breakers. According to some research I have done, every time you add on another extension cord the voltage is cut in half. So at best I would only have 5 amps which is definately not enough. Can anyone suggest a way that I can run 200 feet plus of wiring so that I don't lose any voltage? Thanks.