Appliances that Leak Electricity and How to Plug Them
by Allan Chen

Before you plug in that new electrical gadget for your home consider this: A study by Berkeley Lab scientists reveals that home appliances are using energy even when they are switched off or not providing the service for which they were designed.

T.V. "Many household appliances draw power in their 'standby' mode," says Alan Meier, a scientist in the Energy Analysis Program of Berkeley Lab's Environmental Energy Technologies Division. "These include common household appliances such as televisions, VCRs, alarms, smoke detectors, cordless phones, video games, even rechargeable electric toothbrushes."

Energy specialists call this "leaking electricity" because the devices are using energy without performing their principal function.

"We estimate that the average home leaks about 50 Watts, or 450 kilowatt-hours per year," says Meier. "Since the average residential energy consumption in the U.S. is nearly 10,000 kilowatt-hours per year, this is about five percent of a home's electricity use." The problem is exacerbated by the proliferation in American homes of emerging electronic appliances like burglar alarms, garage door openers, telephone answering machines, cordless phones and others.

Meier and colleagues Steve Greenberg of Berkeley Lab, and Leo Rainer of the Davis Energy Group estimate that the national power consumption lost to leaking electricity is 5 gigawatts (billion watts), or the equivalent of five standard power plants, and growing. The research team is now investigating ways to staunch the flow of wasted wattage.

Reducing or eliminating leaking electricity would have a number of benefits beyond saving energy.

"It would remove a potential fire hazard or a danger of shock when the appliance is 'off ' it is truly off," says Meier. Leaking electricity also generates heat, which increases a home's air conditioning load. And the "leaked" electricity has a poor power factor, meaning that it can degrade the performance of sophisticated electronic equipment such as the home personal computer.

Meier and his colleagues have found some technical options for reducing these leaks. For some appliances, energy leaks emerge from the low voltage power supply (the little black box that plugs into the wall outlet). Cheaper models of these power supplies often have high power losses. Such models can be replaced with existing higher quality, Underwriters Laboratory-certified power supplies with a three-way on-ready-off switch. In the off position, an appliance equipped with one of these is truly turned off.

For consumers with certain battery-based appliances like portable computers or cordless telephones, existing photovoltaic technology provides another solution. Solar PV-charge kits can take the place of the household outlet for keeping some batteries charged.

Finally, to address the power draw of appliances that need continuous energizing such as TVs and VCRs, Meier, Greenberg and Rainer have designed a circuit that draws power only when a small battery mounted in the appliance needs power. The rest of the time, the circuit switches itself off. Manufacturers could design these circuits into their appliances.

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