1. Units Of Electricity Ashfield Direct Learning Holly Millar Ks4 Energy

2. What are units of electricity?  Electrical Units are a measure of the electrical energy used.  An Electrical Meter (like the one you will have in your home) measures the amount of energy used in Kilo-watt hours. Your meter at home may look like this………

3. The Kilowatt-hour  A kilowatt-hour is a unit of energy  It is used in calculating domestic electricity bills and is measured on a meter in the home  REMEMBER: it is NOT a unit of power…..that is the kilo-watt or watt!

4. Kilowatt-hour calculations…..  ENERGY TRANSFERRED (kWh) = POWER (kW) x TIME (h)  EXAMPLE : a 2000W electric hot plate is switched on for 90 mins…… E = P x t = 2kW x 1.5 hours = 3 kilowatt hours E P T

5. Examples of kilowatt-hours….  A 200 watt T.V set ……..transfers 1 kWh of energy if it is switched on for 5 hours  A 500 watt vacuum cleaner……..transfers 1kWh of energy if it is switched on for 2 hours