Power: A 400-W computer (including the monitor) is turned on for 8.0 hours per day. If electricity costs 10¢ per kWh, how much does it cost to run the computer annually for a typical 365-day year?

Question

Quizplus · Accepted Answer

The computer uses 400 W of power for 8 hours per day, so it uses 400 W * 8 h/day = 3200 Wh/day of energy. In a year, it uses 3200 Wh/day * 365 days/year = 1,168,000 Wh/year of energy. At a cost of 10¢ per kWh, it costs 10¢/kWh * 1,168,000 Wh/year / 1000 Wh/kWh = $116.80 per year to run the computer.

Power: a 400-W Computer (Including the Monitor) Is Turned on for 8.0