http://ca.shine.yahoo.com/which-is-better--dishwasher-or-washing-dishes-by-hand-.html
<<A study out of the University of Bonn in Germany, reported by Pablo Päster in the May/June issue of EatingWell Magazine, found that washing a load of dishes (12 place settings) by hand uses on average 27 gallons of water and 2.5 kilowatt-hours of energy to heat the water-equivalent to running a hair dryer for 2 1/2 hours. (Not to mention the parental energy it takes to get your kid to wash all those dishes in the first place.) By comparison, an energy-efficient dishwasher uses about 4 gallons of water and 1 kWh of energy per load. (And over the course of a year, using the dishwasher saves more than 400 hours of labor!) Researchers also found that dishwashers cleaned better, as half of the hand-washers failed to reach an "acceptable level" of cleanliness. >> harry
