From Wired News Furthermore:
IT folks used to advise leaving computers on all the time to avoid wear and tear. But components are much more reliable now, and new research shows there’s no reason not to go green and turn PCs off when not in use. Tests at the University of Waterloo in Canada indicate that current computers use about 110 watts of electricity while booting up and 60 watts when idle; a 17-inch CRT monitor uses about 75 watts. PCs in sleep mode draw about 35 watts, roughly equivalent to three clock radios. Multiplied by hours of standby time and millions of PCs worldwide, that adds up to a big drain. Infineon Technologies estimates that a 1 percent decrease in U.S. standby power use would save 360 megawatts — equivalent to a medium-size power plant.