cfl`s are say half the price of the hps, but after waiting and feeding all that time with hps you can increse the yeild ten fold and only do say three grows a year, where with the cfl your growing year round and no getting from grow to grow without running out of weed, then you have to go buy street weed, so the cash adds up in favor of the hps all the time, if your worried about the bill jumping up then run your cfl`s until flower so a couple of weeks and then flip to hps, in the cold they if anyone will putit down to extra heaters etc, and as long as you pay and don`t fiddle the meter, no one cares ..