Paying for ElectricityPaying for Electricity

How much does it cost to watch How much does it cost to watch T.V. for 2 hours?T.V. for 2 hours?

Kilowatt hoursKilowatt hours

• We pay for the energy that we use.

• The energy is measured in kilowatt hours or kWh by the electricity meter.

• kWh are called UNITS

• You pay about 6p for every kWh or Unit you use.

PowerPower

• Power is measured in Watts (W) or Kilowatts (kW)

• There are 1000W in a kilowatt.

• To work out kW divide the Watts by 1000

ConversionsConversions

• Convert the following to kW

• a)1000W

• 1000/1000 =1kW

• b) 500W

• 500/1000 = 0.5kW

• c) 100W

• 100/1000 =0.1kW

TimeTime

• Time needs to be in Hours (kilowatt hours remember)

• There are 60 minutes in 1 hour

• To get hours divide the number of minutes by 60

The calculationThe calculation

• To work out how many kilowatt hours are used just multiply kilowatts by hours.

• A 2kW fire is switched on for 3 hours. How many kilowatt hours were used?

• If each kWh costs 6p how much did it cost to have the fire on?

calculationcalculation

• Kilowatts x hours = 2 x 3 =6kWh

• 6kWh x 6p = 36p