HIDs use alot more power. cfls are generally low wattage light sources (commonly in the 10w-42w range, although there are cfls as small as 2w and as big as 200w). HIDs on the other hand come in wattages of 400w, 600w, and 1000w (they come in other wattages as well, but 400, 600, and 1000 are the...