When it comes to controlling your computer's energy usage, a little effort can go a long way.

That's the idea behind Edison, Verdiem's new power management software that's available for free download here. (You have to be running Windows XP SP2 or Vista to use it.) Edison lets you schedule when it should turn off your display, power down your hard drive and suspend your computer based on number of minutes of inactivity. A easy-to-use slider bar with Save Less on one side and Save More on the other is preconfigured with Verdiem's recommendations, though you can also customize the settings.

"What you will see is how changing your power settings can reduce the amount of electricity you use, and by extension, your computer usage's carbon footprint," states Wired's Gadget Lab blog, whose screenshot of what you'll see is perhaps the best explanation of them all.

We're not talking big bucks in terms of savings -- annually, around $32, 362 kilowatts per hour and 494 pounds of carbon dioxide -- but the collective impact makes it an app worth trying. "Most people are really unaware how much energy PCs are wasting, and we want to draw a lot of attention to that," Allison Cornia, Verdiem's VP of marketing, told CNET's Crave blog.

That energy consumption is going to only increase. According to Lori Wigle, president of the Climate Savers Computing Initiative (which, along with Microsoft, is backing Edison), carbon emissions could double by 2020 based on the high-tech industry’s anticipated growth.

For the record, this past weekend I downloaded Edison and can attest to its ease of use. At first it didn't seem to work: I customized the app to turn my display off after a minute to test it out, and nothing happened. I contacted Verdiem's help desk using the chat function on its Web site and was advised to close Edison in my system tray, then restart it. That did the trick.