Sure, buying an EPEAT Gold or Energy Star 4.0 certified computer will take you far towards minimizing the environmental footprint of that computer system. How we use our computers, though, is also critical in addressing the energy consumption issue.

The majority of energy consumed by our computers happens when they are idling. Estimates suggest that up to 85% of the energy used up by computers occurs when we are away from the machine--at lunch, at meetings or simply not at the office. There are two simple solutions to dealing with this:

1. Turn it off!

For a while, a great debate waged as to the benefits of turning a computer off when leaving work at night as opposed to leaving it on. Would turning it off wear out the moving parts? At some point in the past, the answer probably was "yes" or at least "maybe." But advances in drive technology and the reduction of physically moving mechanical parts in computers has disposed of this argument. If this is still your concern, lay it to rest and shut down your computer before you leave.

A second reason why computers are often left on at night is to allow for scheduled data backups or other maintenance. If this is how your systems run now, consider changing how your data is backed up. For offices with multiple computers, central data storage (servers, shared drives) is a better solution for back up and file storage in general. Let these machines handle your data and back up requirements so other systems can be turned off.

For offices with one to three machines that do not need to share data in this way, individual backups can be done to CD, DVD, external drives or online services. These backups can often be set up to be done incrementally so, after a baseline backup is done, only files that have changed are backed up each time. In the case of many online backups, these backups are often done throughout the day, meaning that the file you created 15 minutes ago is probably already backed up. If backing up to CD, DVD or other local storage, schedule automatic backups for over a lunch hour or during routinely scheduled staff meetings.

In the initial example of a computer using 100 watts of power running 24 hours a day, 365 days a year, energy consumption would cost approximately $100 a year. Running the same computer only 8 hours a day drops the cost by two thirds to approximately $33 a year--and the cost would drop even more if the computer is off for entire weekends as well. Turning off any technology when it isn't in use is the single easiest thing any individual or organization can do to conserve the energy used by these machines.

2. Give it a Rest!

Turning off your computer at night, over the weekend or during times when you will be away from it for an hour or more can have a huge impact on energy consumption. When turning your computer off isn't an option, make sure it is at least taking advantage of whatever "sleep mode" functionality it has. Putting a computer into sleep mode basically shuts or slows down computer components like the monitor and hard drive, helping the computer use less power. To check your computer's available power management settings, check the following:

On a Macintosh:

1. From any application select the Apple menu
   
2. Select "System Preferences..." (OS X) or "Control Panels" (OS 9) and then click on "Energy Saver"

On a Windows-based computer:

1. Point your cursor at the desktop background and right-click
2. Choose "Properties" from the pop up menu
3. Go to the "Screen Saver" page; in the lower right-hand corner near the ENERGY STAR® logo click the "Settings" or "Power" button. This brings up another dialog box where you choose power management settings.

From these screens, you can set when the monitor is turned off, when the hard drive spins down and when the computer will go in to "system standby" or "sleep mode". Generally, turning an unused computer monitor or hard drive off after 10 or 15 minutes and sending a computer into standby or sleep mode after 30 minutes is a reasonable rule of thumb. These settings will minimize power use but also make it so your computer will wake up quickly when you return from that meeting or meal. These and other recommendations regarding turning off and using standby settings can be found in the Green Computing Guide from the University of Colorado at Boulder.