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matthewelvey
matthewelvey asked in Science & MathematicsPhysics · 1 decade ago

TV power strip magic - Is National Geographic clueless?

At http://www.nationalgeographic.com/everyday/greenho... the first tip is:

Power outlet vs. Power strip: Plugging your TV and VCR/DVD into a power strip rather than an outlet will save you about 2 percent on your annual electricity bill. Even when you turn these appliances off, they continuously leak up to 15 watts of electricity if they're plugged into an outlet. When plugged into a power strip, however, these appliances leak only about one to three watts.

Now this seems completely nonsensical to me. What magic in a normal power strip could possibly reduce the electricity the TV pulled, other than the off switch? I ask this in Physics, because I want an answer from someone even more knowledgeable than me in the fundamentals of electricity (E&M), not some well-meaning tree-hugger who just parrots what others say if it sounds good. Of course, using the off switch would save watts, but I'm certain that if a TV pulls 10 watts when off, it's going to pull that whether plugged directly into the wall, or via an 'on' power strip, and will pull nothing via an 'off' power strip, but 'one to three watts'? No way it'll pull that. Right? My kill-a-watt indicates National Geographic is full of it.

Update:

Yeah, I agree, that's all there is to it, which confirms that National Geographic's talking nonsense when it says:

"When plugged into a power strip, however, these appliances leak only about one to three watts. "

Update 2:

Also, with newer TVs, all this is becomes unnecessary, as they don't pull 10 or 5 watts when on standby. Since 2006, new TVs can't pull more than 3 watts. That's been the Maximum Power Usage (Watts) since January 1, 2006.

After 2010 ends, the legal max drops to 1 watt.

Plus, the chips that make this possible cost way way less than a power strip.

Update 3:

Whoops, clarification, this is the max when they're in Standby-passive Mode. The max when they're on is higher, more complicated, and based on screen size.

Update 4:

What National Geographic has written suggests (falsely) that you save energy by using a power strip even if you never turn it off. It's not true.

1 Answer

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  • billrussell42
    Lv 7
    1 decade ago
    Favourite answer

    There is no magic in the outlet strip except it has a switch on it, which completely turns off the power to anything plugged into it.

    And that is the point. Turn the switch off and save those few watts.

    You can do the same thing by pulling the plug on the TV. But turning it off with the remote does NOT turn the TV completely off, hence the 5 watts drain.

    .

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