This question made me laugh. Dude you need alot more. In fact your better off getting a even a 100 or 70 watt hps street light assembly. You are not going to get shit with that set up there. You got some major, major issues. To grow weed you need air, light, and water. I pray to God you have water, but that also means that's the only thing you got out of the equation. I think i could get something out of 54 watts. i know that sounds cocky, but I think i could. It would be tough though. When I say something, I'm talking like 5 grams, haha!
Heres some ideas, get an old power supply from a cheap as computer, or an old piece of shit in the basement. The 80mm fans are great for stealth grows. Then go to home depot or wally world and get some 24 inch flouro fixtures 15-20 watts at least if you can. there are two bulbs in most,and they are cheap. buy as many as you can afford, but dude I've seen that shit for like 10 bucks for 2x15watt fixtures. mount that shit above the plants. I mean if you get like 60-120 watts above them preferably in the sub 3000 wave range, it
might get you a quarter. For a little grow though, sometimes it's just cool to grow you own chronic!
good luck, you're gonna need it