Energy-Savvy Computing

Canadians live in a wired society where computers are loved so much that many people often leave them buzzing and churning night and day, needlessly burning a lot of energy.

Such wasteful practices are often based on myths, which if dispelled could lead to significant reductions of energy, operating costs and greenhouse gas emissions.

Myth: Screen savers save energy.
Fact: Screen savers consume almost as much energy as a computer in use (most power consumption comes from the monitor). Choosing a computer's power management feature to turn off your monitor saves much more energy.

Myth: Turning a computer on and off uses more energy than just leaving it on all day.
Fact: The energy used at start up and shut down is only a few seconds worth of normal operating energy. It most often makes sense to turn a computer off or put it in sleep or standby mode, even for only a few minutes.

Myth: Turning a computer on and off frequently shortens the hard drive's life.
Fact: Studies at the Lawrence Berkeley National Laboratory found that computer hard disks are not affected by frequent shutdowns and may actually last longer due to reduced heat stress and mechanical wear. Most computers are designed to start up and shut down 40,000 times.

To test the amount of wasted power consumed by computers in our office, Climate Change Central took some readings from a Kill-a-Watt, a power-use monitor available at most hardware stores. We discovered that one computer and monitor (a desktop with an LCD screen) left idle on weekday evenings and weekends would, in one year, consume a total of 552 kilowatt hours (kWh) of electricity, costing $44.18.

Instead, if the computer was shut down on evenings and weekends, it would consume a total of 43 kWh, at a cost of $3.44 based on the assumptions:

• Cost of electricity = $0.08
• Weekday shutoff: Monday to Thursday from 6pm - 8am
• Weekend shutoff: 6pm Friday to 8am Monday
• Results are for 52 weeks

This calculation would result in an overall power savings of 92 per cent, or $40.74, per computer, per year. When you multiply these savings by many computers in most offices, the reduction in greenhouse gas emissions, energy and cost is significant.

Energy Efficiency Tips

• Turn off your computer's hard drive by putting it in sleep mode if you are away for more than one hour.
• Turn off your monitor if you're away from your desk for even 15 minutes.
• Choose ENERGY STAR® equipment whenever possible.
• Minimize printing and use the double-sided print option if possible.
• Activate your computer's power management features.

DID YOU KNOW...

• New flat-screen LCD monitors use 70 percent less energy than standard monitors and contain 95 percent less lead. Laptops are more energy efficient than desktops.