Your saying 1 outdoor light is racking your bill up? Your screwed then as thats almost no cost at all to run lolYou ll need like 4 cfls minimum to get a scraggly plant and 8 or more to get a decent little plant or an hps to get a truely good plant.A 1000 watt light on 24 hours a day adds about $60 a month to a bill so I guess your bulb adds about 4 bucks amonth to your bill