P1.3 Electrical Energy

The cost of electricity

• The total amount of electrical energy transferred depends on the amount of time a device is switched on and its power rating
• Power is measured in Watts (W) or kiloWatts (kW)
• Energy is measured in Joules (J)

          Energy Transferred (kWh)= Power (kW)  X   Time (h)

          Cost (pence) = Energy Transferred (kWh) X Cost/Unit (pence)