Chapter 9.11 - Paying For Electricity

Question 1

What are the two factors neeeded to calculate energy (J) transfer of devices

Answer 1

• Power (W) (Watt)

* Time used (s)

Question 2

What is the kilowatt-hour (kWh)

Answer 2

• Energy transferred by a device with a power of 1kW operating for a time of 1 hour

• 1kWh = 3.6 MJ
• Typical costs are between 6-15p per kWh