Vampire appliances. (Energy).

You flip off the lights, but an eerie glow remains--the displays and clocks of your cable TV box, VCR, and stereo. These so-called vampire appliances stay awake all night, every night, sucking up an average of 5% of the monthly electric bill, according to Alan Meier, a staff scientist at Lawrence Berkeley National Laboratory (LBNL) in California.

In the 1998 LBNL report Reducing Electricity to 1 Watt, Meier and colleagues estimated this standby power use costs U.S. consumers $3 billion a year, or about $200 per household. This hidden energy use--often generated by fossil fuel power plants--contributes to the production of greenhouse gases, including about 1% of the world's carbon dioxide emissions, according to the International Energy Agency.

TV satellite boxes are one of the biggest standby power guzzlers, using anywhere from 7 to 40 watts, says Meier, partly because they must maintain a continuous connection to the satellite system. Other heavy users include devices with remote controls such as TVs and VCRs, which use an average of 5-7.6 watts. Receivers inside these appliances must stay on at all times, ready to receive a signal from the remote. Appliances that provide clock displays and timers also use quite a bit of standby power (3 watts on average).

Though costs vary, Meier and other researchers contend that it is technically possible for all manufacturers to reduce standby power use to less than 1 watt per appliance without sacrificing convenience or increasing retail prices. Meier says that in U.S. homes alone, a 1-watt limit would cut standby usage by about two-thirds, for a savings of more than 4 gigawatts (the output of four very large nuclear or coal power plants). Shifting to a 1-watt standard further means cutting global carbon dioxide emissions by roughly 0.5%, Meier says.

LBNL lists appliances that use 1 watt or less of standby power on its website at http:/Istandby.lbl.gov/DATA/1WProducts.html. Perhaps the easiest way to buy a standby-efficient appliance is to look for the U.S. Environmental Protection Agency's Energy Star label, which for consumer electronics (such as televisions and VCRs) signifies that the item uses I watt or less of standby power (Energy Star does not apply this same standard to office equipment such as computers, or to large appliances). Also, the September 2001 issue of Consume Reports rates the standby power usage of TV satellite boxes.

Another solution, says Karen Herter, a principal research associate at LBNL who has worked with Meier, is replacing older transformers-the linear power supplies that convert electricity into a lower voltage that small appliances can use--with newer electronic transformers. These "switching power supplies" save power by constantly switching power on and off at a rate so fast--about 20 kilohertz-that the appliance doesn't miss the power. According to the 1998 report, replacing the estimated 1 billion "wall packs" used for cell phone chargers, lighting, and other electronics that are plugged into U.S. homes with switching power supplies could save more than a gigawatt of power.

Herter says, "I think a lot of the manufacturers are starting to recognize standby power as an issue and do something about it." Several, including Pioneer, Sony, and Matsushita, have voluntarily established targets for lower standby power levels. An incentive for other manufacturers is President Bush's July 2001 executive order that all government agencies purchase appliances that use 1 watt or less of standby power, if available.

Until all appliances reform their vampirish ways, Mark Pierce, an extension associate at Cornell University's College of Human Ecology who has written about the issue, says he reduces consumption at home by plugging his VCR and television into a power strip that he switches off when not in use. "No one's saying that we shouldn't have these conveniences," he says. "But since some manufacturers can build appliances to use less than one watt, then why can't everybody--why shouldn't everybody?"