when you say household energy efficient I think you mean CFL's? I'd go for at least the 23watt CFL's if you can get them, they are the 150 watt equivalent bulbs, and 4 of them instead of just 2, the more the better. When dealing with CFL's get more. If you are seriously using incandescent bulbs for that "240watt" number you have up above, you might as well just turn it all off and save the electricity as you won't get any real bud off that...see a took cuttings just didnt want to buy a 240w energy efficent and a no it doesnt take much to root them so do u think 2x 11w house hold enegy efficents would do the job??? thanks allot