Learn about your computer's energy usage

Below is a frequently asked question about computers' energy consumption.

Q: How much energy does my computer use?

A: The annual energy consumption of a computer varies widely, from less than 30 kilowatt-hours (kWh) for a rarely used laptop to more than 1,000 kWh for a large desktop that uses several peripheral technologies and is often left on overnight. While the computer itself usually accounts for the largest share of energy use, the monitor, speakers, printer, modem, router, scanner and other equipment can consume significant amounts of electricity as well. By choosing efficient products and powering down after use, you can significantly reduce your energy costs.

The average desktop computer is in active mode for 2,954 hours per year, in sleep mode for 350 hours and switched off for 5,456 hours. The typical desktop consumes 75 watts in active mode, 4 watts in sleep mode and 2 watts while shut down. These averages translate to a total of 236 kWh per year. However, a desktop computer left on continuously will consume more than 650 kWh annually, and a high-performance gaming system with a powerful graphics card and multiple drives can use even more. By comparison, a midsize ENERGY STAR® refrigerator consumes about 400 kWh per year.

Computers and peripheral equipment are considered "energy vampires," because they consume energy in standby mode. Check out SRP's energy vampire calculator to see what kind of bite vampire appliances take out of your wallet!