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Improving efficiency

Efficient devices use less fuel than less efficient devices.

Efficiency can be improved by:

  • making devices and machines from materials which reduce unwanted energy transfer;
  • improving the technology used, for example modern LEDs are much more efficient than traditional filament bulbs;
  • using insulation to prevent heat energy losses to the surroundings.

Electrical appliances

Many electrical appliances used in the home transfer electrical energy to other non-useful forms.

ApplianceUseful energyWasted energy
Electric kettleEnergy that heats the water.Heat energy store heating the kettle. Heat energy lost to the surroundings.
HairdryerHeat energy store heating the air. Kinetic energy of the fan that blows the air. Sound energy. Heat energy store heating the hairdryer. Heat energy lost to the surroundings.
Light bulbLight energy given out by the hot filament.Heat energy lost to the surroundings.
TVLight radiation that creates images for the user. Sound radiation that creates audio for the user. Heat energy store heating the TV set. Heat energy lost to the surroundings.
ApplianceElectric kettle
Useful energyEnergy that heats the water.
Wasted energyHeat energy store heating the kettle. Heat energy lost to the surroundings.
ApplianceHairdryer
Useful energyHeat energy store heating the air. Kinetic energy of the fan that blows the air.
Wasted energySound energy. Heat energy store heating the hairdryer. Heat energy lost to the surroundings.
ApplianceLight bulb
Useful energyLight energy given out by the hot filament.
Wasted energyHeat energy lost to the surroundings.
ApplianceTV
Useful energyLight radiation that creates images for the user. Sound radiation that creates audio for the user.
Wasted energyHeat energy store heating the TV set. Heat energy lost to the surroundings.

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