Slideshow: 5 Tools to Prevent Energy Waste in the Data Center

These conveniences come at an overlooked price: Keeping a PC running 24/7 can cost as much as $375 per year, depending on the type of computer and monitor, as well as energy rates in your region. Shutting down a PC for 16 hours or so per day can cut those costs by 66 percent. That translates to potential savings of more than $120,000 if you have 500 machines.

[ InfoWorld debunks 10 myths about power saving. | Learn more about the ROI of PC power management. | Learn about free power management alternatives to pricey management suites. ]

Rather than relying on end-users to power down their machines and monitors each night, then reboot them in the morning, organizations are increasingly turning to power management offerings, products capable of powering machines on and off at predetermined times to ensure that they're awake when it's time for work, backups, or patches. Otherwise, they'll be asleep so as not to waste energy and money.

I had an opportunity to test out three power management software systems aimed at the enterprise desktop market, from vendors Autonomic Software, BigFix, and Symantec. Notably, all three software products are part of suites intended to provide a great many more PC management functions beyond control over power usage, such as remote desktop support, configuration and patch management, vulnerability assessment, and endpoint protection.

Windows XP, Vista, and Windows 7 already come equipped with tools for putting a machine in a low-power state (ranging from standby and sleep to complete shutdown) at a set period of time or a predetermined amount of inactivity. Why, then, would an organization invest in a separate power-management tool? The reason: These tools offer several useful features not available in Windows. For example, they can locate systems with hibernation disabled and re-enable it. They can shut down applications and save files before powering down the system. Admins can set different durations of inactive time before hibernation is triggered; for example, to prompt a machine to sleep after only a couple of minutes of inactivity during evenings and weekends -- but not until, say, a half-hour during the work day. Admins also can use the tools to automatically restart PCs at predetermined times, such as in the middle of the night for software updates and patches, or in the morning, shortly before the users arrive.