Office equipment is the fastest-growing electricity load in the business sector, says the U.S. Environmental Protection Agency. No wonder: a desktop computer draws around 200 watts, and, the EPA has determined, some 30% to 40% of those computers are left on round the clock. As a result, computers alone scarf down 5% of the nation's output of commercial electricity. Unless something's done, that portion will reach 10% by the year 2000.

Something is being done -- not to persuade businesses to turn off their computers when not in use but to get idle computers to demand less current. Responding to conservation goals for office computers and printers recently set by the EPA's Energy Star Computers program, semiconductor vendors such as Intel, Advanced Micro Devices, and Texas Instruments have agreed to append a power-down function to their chips. Similar to the battery-saving function of laptops, the resultant "sleep' state is automatically induced after a PC has been idle for a prescribed interval. A desktop's appetite for alternating current then drops to less than 30 watts. The EPA estimates that its better-by-the-dozin' campaign ultimately will cut corporate computer electricity bills by half, saving $2 billion a year -- about what it costs annually to provide electricity to all of Maine, Vermont, and New Hampshire.

Last month manufacturers of desktops that incorporate sleep-inducing technology -- which collectively account for about 60% of the microcomputers sold nationwide -- began displaying the EPA's special seal of approval. Among the beneficiaries: taxpayers. Starting in October the world's largest purchaser of computers -- the federal government -- will be required to buy the energy-efficient systems.

For more details, call EPA Energy Star manager Brian Johnson at 202-233-9230.