One of the biggest problems with growing indoors is the light bill goes up after you fire up all your new lights. It's a nuisance for the legal grower and a danger for the unlicensed grower. Here is a way to reduce the amount of electricity you use so that when you add your lights there is little to no bump in your light bill.
About 15 years ago we installed "The Little Gray Box" on our water heater. It is really just a timer, much like the one used for grow lights. But, this one regulates how often your water heater in your house comes on. Why heat the water at night when you are sleeping? You aren't using hot water, you don't need hot water so why waste the energy heating water you don't need or want? My little gray box is set to come on for one hour in the morning just prior to us getting up, and one hour in the evening so we have hot water for showers and stuff. We have all the hot water we need. The first month our electric bill went down to $25 from $60 the previous month. The only difference was the little gray box. You can run a 600W ballast for the difference of the savings with little to no increase in your light bill. You might even experience a bit of a drop.
Check it out at this link:
The Little Gray Box Water Heater Timer - Intermatic Model WH40
I got mine at Home Depot. I don't know if they still carry it, but you can ask.