December 14, 2007
| by Steven Castle
Your DVD player is wasting energy. Chances are, so are your TV, audio/video receiver, video game console, desktop or notebook computer, printer, scanner, fax machine, cell phone charger, cordless phone system, microwave oven and more.
How can that be? As long as they’re plugged in, most of these electronics are still using electricity when they’re turned off. That’s right, as in OFF, which is supposed to mean OFF—except in this day and age, when apparently OFF means something can still draw power. And that costs us money, wastes energy and contributes to our global warming problem. (More than 40 percent of all global emissions of carbon dioxide, a leading greenhouse gas, is caused by electrical power plants.)
This on-when-off issue is called “vampire” or “standby” power, the latter not to be confused with a “standby” or “sleep” mode on a computer. In this case, standby means “off.” Standby power expert Alan Meier of Lawrence Berkeley National Laboratory in Berkeley, CA, says a typical home can have more than 40 devices using energy in “off” or low-power modes. That can translate into 9 percent or more of your electric bill. According to the International Energy Agency, this amounts to about 200 to 400 terawatts of power per year, or $4 billion annually. Suffice it to say, that’s a lot of wasted juice.
So why are your electronics using power when they’re off? There are different reasons. Anything with a display clock, like a microwave oven, a coffee maker, a VCR (even if you never set the clock) will continue to draw some power as long as it’s plugged in. So will most electronics and appliances with keypads. So will anything with a remote control, as a small amount of power is used by the remote sensor to detect a signal. Some electronics, including TVs, have become rated by Energy Star for using less than 1 watt in standby (“off”) mode, as the remote sensor only uses a tiny amount of power.
In addition, says Meier, some manufacturers designed DVD players, for instance, to keep some circuits energized when the unit is turned off, which can make an eight-fold difference and draw as much as three to four watts when “off.”
The most ubiquitous standby power loss problem, though, is through AC adapters, or power supplies. These come in both the external variety used by notebook and laptop computers, printers and a myriad of electronics, as well as internal power supplies in desktop computers and other electronics. Many power supplies are inefficient and result in power loss when converting the AC power to DC power needed by the electronics. These are conversion losses, but there are also no-load losses, when an external power supply may be detached from a laptop computer but remains plugged in. “In that case, the standby load is for nothing, and it is still drawing power and dissipating it as heat,” Meier says.
Steven Castle is Electronic House's managing editor. he has been writing about consumer electronics, homes and energy efficiency topics for two decades. He is also the co-founder of GreenTech Advocates