Electric blankets convert energy stored as electricity into heat energy. Blankets are available using different technologies and are rated at different wattages, so the running costs vary according to the type of blanket and its temperature settings. Expect to pay anything between 50 cents and £1.30 per week.
Wattage and Temperature
The amount of electricity used to convert electrical energy into heat is measured in watts. Higher-wattage blankets use more electricity than lower-wattage blankets, and maintaining higher temperatures uses more watts than running the blanket at lower temperatures.
Under identical usage, thermostatically controlled blankets are more efficient and cost less to run than blankets constantly producing heat. Any blanket left on standby or switched off by its thermostat continues to consume power as the blanket transformer converts 110 volts to a lower voltage.
The Running Cost
As of September 2010, the average price of a kilowatt of electricity in the U.S. is between 7.93 cents in Washington and 27.85 cents in Hawaii. Running a typical 100-watt double blanket for 10 hours a night costs between 7.93 cents and 27.85 cents per night.