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Domestic Electricity

Much of the energy transferred in homes and industry is electrical energy from powerstations .

We use electrical energy because it is so versatile and can be readily transferred as forms that are useful to us:

heat (thermal energy) - to heat our homes, heat water for washing, heat food - cooking, refrigeration unit operation etc.

light - to illuminate our homes and communicate via a TV screen or computer screen etc.

sound - for information (TV, Computer), entertainment (TV, music system, games console) etc.

movement (kinetic energy) - to operate vacuum cleaners, washing machines, tumble driers etc.

You should be able:

to specify the energy transfers everyday electrical devices are designed to bring about;

to give examples of everyday electrical devices designed to bring about particular energy transfers.

The quantity of electrical energy an appliance transfers depend on:

how long the appliance is switched on;

how fast the appliance transfers energy (its power).

The power of an appliance is measured in watts (W) or kilowatts (1kW = 1000W).

The amount of energy transferred from the mains is measured in kilowatt-hours, called Units by the electricity boards

energy transferred (in kilowatt hour, kWh) = power (in kilowatt, kW) x time (hour, h)

You should be able, when provided with suitable diagrams of a digital domestic electricity meter, to calculate the number of Units used.

The cost of this energy can be calculated using: total cost = number of Units x cost per Unit.

Now look at the page on Mains Electricity. It will take you to topics linked with domestic electricity.