By now, most of us know that leaving our computers on when we’re not using them wastes energy. But exactly how much energy?
According to the U.S. Environmental Protection Agency’s Energy Star program, using the power management functions on your computer properly can cut your electric bill by up to $75 a year. But even more impressive is the greenhouse gas savings we could generate by managing our computers better: according to Carbonfund.org, activating the power management features on 100,000 computers and monitors would reduce carbon dioxide emissions by more than 11 million pounds a year. That’s like burning 13,000 fewer barrels of oil, eliminating 5,000 car trips from Los Angeles to New York or planting 1,000 acres of trees

So why don’t more people set up their computers to be more energy-efficient?

Uncertainty and fear, according to support.com.

A remote tech support company based in Redwood City, California, support.com recently commissioned a survey of 1,000 Americans to learn what they knew about computer power management. The company found out that, while 87 percent of people said they were aware of those functions on their computers, more than half (57 percent) hadn’t activated them. Many of those said it was because they didn’t know how to set the functions, or they were afraid of doing it wrong.

Looking at those results, support.com decided to introduce a new service called "Green Computer." The free service, available as of this week by calling 800-PC-SUPPORT, helps people customize their computer’s power management functions to their personal preferences, walks through ways to make sure those functions are working properly, and suggests other ways to save on computer energy consumption. Each call takes about 10 to 15 minutes.

"In talking with consumers about energy-efficient computer use, we found there was a lot of confusion," said Scott Herring, vice president of marketing for support. com. "Some people weren’t aware of the power management functions, others didn’t know how to activate them, and even more didn’t understand the difference between a ’screensaver’ and putting a computer into ’sleep mode.’ People were surprised to hear that a screensaver is not an energy saver. By offering this free Green Computer service, support.com expects to help a lot of consumers perform a simple but effective act to save energy."

Besides activating your computer’s power management functions, you can cut your desktop’s energy consumption by following these other tips: turn your computer off completely if you know you won’t be using it for a few hours, make sure games and third-party software are shut down before putting your computer into sleep mode (otherwise, they might continue running in the background), disconnect your virtual private network when you’re not using it (again, leaving it connected can prevent your computer from sleeping properly), and close any open Web windows so banners and ads don’t interfere with your PC’s nap.

Oh, and forget the screensaver. Just like it’s best for people to go to bed with the TV off, computers sleep better (more energy-efficiently, anyway) with a blank screen.