Putting a personal computer to sleep is typically the only means for users to conserve electricity, besides frequent, often inconvenient, shutdowns. Now a new focus of energy savings for the PC has emerged--its power supply.
When a PC is operating, its power supply typically converts only 60 to 70 percent of the 120-volt AC power into the 12-, 5- and 3.3-volt DC juice the internal system components need. The rest is mostly lost to heat. Each of the estimated 205 million PCs in the U.S. consumes an average of about 300 kilowatt-hours of power annually, and that figure does not include the monitor's energy usage. Making PC power supplies 80 percent efficient, researchers say, could shave U.S. energy use by 1 to 2 percent and pare $1 billion or more from the nation's yearly electric bills while cutting emissions from generating plants significantly.
This article was originally published with the title Power-Thrifty PCs.