Efficient devices use less fuel than less efficient devices.
They can operate at a lower power because less of the supplied energy store is wasted.
Efficiency can be improved by:
Many electrical appliances used in the home transfer electrical energy to other useful forms.
|Appliance||Useful energy||Wasted energy|
|Electric kettle||Energy that heats the water.||Heat energy store heating the kettle. Infrared radiation transferred to the surroundings.|
|Hairdryer||Heat energy store heating the air. Kinetic energy of the fan that blows the air.||Sound radiation. Heat energy store heating the hairdryer. Infrared radiation transferred to the surroundings.|
|Light bulb||Light radiation given out by the hot filament.||Infrared radiation transferred to the surroundings.|
|TV||Light radiation that creates images for the user. Sound radiation that creates audio for the user.||Heat energy store heating the TV set. Infrared radiation transferred to the surroundings.|