By Janet Raloff
Several years ago, scientists at Lawrence Berkeley (Calif.) National Laboratory launched an energy conservation campaign against electronic goods that continue to draw power when switched off (SN: 10/25/97, p. 266). A typical home squanders 50 watts to this leakiness. The lab has now gone on to calculate electrical consumption by office computers, copiers, and related equipment that have ostensibly been turned off. According to the new estimates, such equipment wastes 71 terawatt hours per year nationally—or nearly 2 percent of the country’s electrical production.
Roughly 75 percent of this waste occurs in commercial offices, another 12 percent in home offices, and the rest in industrial settings. Desktop computers and monitors are the biggest offenders, report Jonathan G. Koomey and his colleagues in a quarterly newsletter published by the lab. On a national basis annually, they say, each of these components wastes 14.3 TWh. Copiers lose another 7.6 TWh, laser printers more than 6 TWh. Fax machines and inkjet printers each leak an additional 3 TWh.
Simply pulling the plug on office equipment overnight could save up to 7 TWh per year, the LBNL scientists calculate. Furthermore, replacing all office machines with units that snooze—power down when not in active use but still turned on—would save a whopping 17 TWh per year.
Correction: Several of the numbers given for energy waste are actually total power consumption when the devices referred to are on. For instance, 71 terawatt hours is the electricity usage of office equipment in the United States, not waste. Also, the study examined energy savings from turning off unused equipment at night, not “pulling the plug” on them.
