Have you ever wonder just how much electricity our home appliances use on a yearly basis? The formula to calculate home appliance electricity usage is simple:
(Wattage × Hours Used Per Day ÷ 1000 = Daily Kilowatt-hour (kWh) consumption
So a typical Window fan will cost you:
(200 Watts × 4 hours/day × 120 days/year) ÷ 1000
= 96 kWh × 8.5 cents/kWh
= $8.16/year
Personal Computer and Monitor:
(120 + 150 Watts × 4 hours/day × 365 days/year) ÷ 1000
= 394 kWh × 8.5 cents/kWh
= $33.51/year
As you can see, window fans and computers don’t cost that much. However, if you have a lot of them and they’re on 24/7, it’ll add up. So turning them off is still a good way to start saving energy, for you pocket, and for the environment.
Source: EERE