Are you spending 25 cents a night to keep your computer on?

Wynn Brower, age 10, figured that his family was wasting $1 every night that they kept all four computers on. At just 25 cents per computer per night that adds up to $365 for his family each year. He won an award at the science fair, then went on to save his own Monroe County, Indiana, $25,000 a year by getting them to turn off its 550 computers overnight.

I had scoffed when a computer savvy friend scolded me for leaving my computer on all the time. You must really love Con Ed, she said. I didn't think I was using much electricity at all. In the large scheme I'm not. But if everyone does it every night, then we all are. Brower's project is a great reminder that even though our computer may sleep and the monitor may go dark, we are still wasting a lot of energy.

Obviously, the amount of power and money you waste depends on how energy efficient your computer is and how much you're paying for power. Arizona Public Service Company estimated how much it costs to run various office equipment.They calculated that a computer costs $39 to run 24 hours a day for a full year. A 15-inch monitor was $54. A laser printer was $44. Their calculations for what it saves by turning it off overnight were smaller than Bower's -- turning off all three would save $9, $12 and $14 a year. That's only 2.4 cents for just the computer overnight, but nearly 10 cents for all three.