[. . . ] [. . . ] kWh/year (kilowatt-hours per year) is a measure of energy (electricity) use. Only standard size clothes washers are used in this scale. Clothes washers using more energy cost more to operate. This model's estimated yearly operating cost is: $40 when used with an electric water heater $23 when used with a natural gas water heater Based on eight loads of clothes a week and a 2005 U. S. Government national average cost of 8. 6¢ per kWh for electricity and 91¢ per therm for natural gas. [. . . ] [. . . ]