We have all-electric, no gas anything. Our last electricity bill was $73 and my wash routine is super heavy-duty. My dd goes through about 12-14 diapers a day at two years old, simply because she tells me as soon as she wets one, and once our twins are here, well... I can guarantee you that we would be spending more than $73/month to diaper them. I bet we'd be spending at least that much just to use cheap sposies on my dd, and that's the cost of my WHOLE electricity bill, not just what I spend on diaper laundry.
We're an all-cloth house; the laundry is always going! But we don't use artificial lights during the day, don't use the AC or heater much, boil water on the stove instead of running water waiting for it to heat for baths and dishes, etc. I'm the master at keeping our bill below $90 for an 1800 sq. ft. house! I would not be that good at hunting down coupons to keep disposable diapering as cheap as it could be, though.