The Energon Pub

The amount of energy a specific appliance consumes can be illustrated in the following formula:

Wattage x Hours Used Per Day
1000

= (1 kilowatt (kW) = 1,000 Watts)
= Daily Kilowatt-hour (kWh) consumption

Multiply this by the number of days you use the appliance during the year for the annual consumption.

You can then calculate the annual cost to run an appliance by multiplying the number of kWh per year used by your electricity suppliers standard electricity charge per kWh consumed, typically around 6.8p/kWh

example
2. Check how much electricity your personal computer and monitor use

Personal Computer and Monitor (220+150)
= 370 Watts x 4 hours/day x 365 days/year
1000
= 540 kWh x 6.8 p / kWh
= £36.73 / year