Washing machines are certified as high-efficiency by the federally-sponsored Energy Star program and the Department of Energy. High-efficiency washers are required to use 30 percent less energy than traditional washers, and most of these washers use 50 percent less water than traditional models.
High-efficiency washers are rated based on multiple factors outside the raw amount of electricity required to power the appliances. The amount of energy required to heat the wash water and dry the clothes after washing is taken into consideration, as 80 percent of the energy used by a machine goes towards heating water. While these washers cost more than traditional washers up-front, Energy Star reports an average savings of $135 yearly in utility costs. Federal and local rebate programs are sometimes also available to refund $100 to $200 of the cost of these washers.
The main method of reducing these values is to use less water and remove as much water as possible during the spin cycle. Thus, special high-efficiency detergents are needed when using a high-efficiency washer since less water is used. High-efficiency models do not use an agitator, which use mechanical power to beat dirt out of clothing. Removing the agitator saves energy and makes more space within each wash, so fewer washes are required.