[Hidden-tech] what uses electricity when it is plugged in?

[Chris Hoogendyk]

On 9/22/11 5:12 PM, Robin MacRostie wrote:
> This may sound silly, but it's one of those little household details that that create tension in a 
> household.  An article on the internet said:
>
> "...Many of us with use the remote to switch off the TV or stereo, leaving the appliance running 
> on standby.
>
> This actually means the appliance is still using up electricity and wastes a considerable amount 
> of energy. By switching off at the main power button, or even the socket, you could be saving both 
> energy and money.
>
> Items left on standby use up to 85% of the energy they would use if fully switched on. An extra 
> million tons of carbon will be released into the atmosphere through this power wastage..."
>
> I need a real, accredited, expert on electricity use to ask this question:
>
> One of our housemates insists that unplugging anything saves electricity.
>
> I had heard something like that and  try to unplug the power strip with computer and all 
> peripherals at night.
>
> I also unplug the cellphone charger.   If I do that, doesn't it also make sense to unplug the 
> battery chargers?   What about the emergency lights that are plugged into the socket?    They are 
> set to "auto" so that they will go on in a power failure.
>
>  Now I'm feeling really guilty.
>
> How about the portable landline phone?  The fax machine?   Then I have to reset the date every 
> day!  The washer and dryer in the basement?
>
> Do I really save a bunch by unplugging the lamps, the blender and the coffee grinder?

I'm sure you will get a bunch of answers from some truly qualified electrical engineer types. 
However, a couple of points seem pretty obvious.

85% doesn't make sense. Assuming your equipment is relatively recent (say, not 15 years old or more 
[out of the hat]), it should drop power to the major power eating components. So, a computer or TV 
will drop power to the screen, and a computer should spin down the hard drive. The standby mode is 
then something that uses enough power to be able to sense the remote telling it to revive the other 
components. That standby does represent power use, but it should be a small percentage of the full 
running device.

Wall warts -- rechargers -- do use some energy even when they aren't charging.

Most power strips have a toggle switch. If you flip the toggle switch, and all your stuff, including 
wall warts, goes through the power strip, then you should be good.

Coffee grinder?? I don't see how that could have any use for power if you aren't pressing down on 
the button to make it grind. Things that have clocks ought to be very minimal.

You could unplug everything and go out and watch your electric meter. Then plug in the things with 
the clocks and go out and watch your electric meter. Then watch your electric meter when you have 
things really running. In some European countries the electric meter is in a closet indoors. I 
always thought that was a good idea, because then it is easier for you to get feedback on what you 
are using. Even granting that it is slightly crude, it is after all the bottom line -- it's that 
meter that determines what you pay.


-- 
---------------

Chris Hoogendyk

-
    O__  ---- Systems Administrator
   c/ /'_ --- Biology&  Geology Departments
  (*) \(*) -- 140 Morrill Science Center
~~~~~~~~~~ - University of Massachusetts, Amherst

<hoogendyk at bio.umass.edu>

---------------

Erdös 4