Vampire
power!
(aka
standby power)
Things
that use electricity even when they're
off
By now you've probably
heard that lots of electronic equipment (like a TV)
uses some electricity even when it's
off. Is the amount significant? Yes.
It's not the biggest part of your bill, but since
it's possible to save energy here, you might as
well. Standby power accounts for about 5% of
household electricity use in the U.S., and 10-15%
in Japan, Germany, and the Netherlands.
(EPA,
accesed 7/08)
There are two kinds of things that use
vampire power:
- Devices in
standby. When you grab your TV's
remote control and press ON, the TV has to be
getting a little juice already so it can receive
that ON signal and respond to it. It's "standing
by" waiting for you to turn it on with the
remote. That's where we got the term "standby
power". Other things that use standby power
because they're waiting to respond to a button
press are DVD players, stereos, and microwave
ovens. Typical standby use is 10 watts, though
really wasteful devices could be as much as 25.
Super-efficient devices use as little as 1
watt.
- Transformers.
All your life you've used those big
electrical plugs like the one pictured at right,
but you probably didn't know what they were
called. They're called transformers,
because they transform electricity from AC to
DC. The problem is that most of them are cheaply
made and continue to draw some electric even
when the device they're powering is turned off
(or in the case of a cell phone, even when the
phone is fully charged). If the transformer is
warm even when the device is off, it's using
phantom power, as much as 10 watts.
Let's do an example. You turn your TV
off, but it continues to draw some power so it can
respond to the remote control when you press the ON
button. The standby amount is 10 watts. From our
cost page page we can see
how to estimate the cost:
- 10 watts x 24 hours/day x 30.44 days/mo. =
7306 watt-hours
- 7306 watt-hours = 7.3 kWh
- 7.3 kWh x 10¢ = $0.73/mo.
So one 10-watt TV isn't gonna put you in the
poorhouse any time soon. But you might have
lots of devices, or some devices that use even more
than 10 watts. That's why standby power accounts
for 5% of U.S. household use on average.
 How
to combat vampire power
- When buying a new device, get a
low-vampire-power version. Look for the
EnergyStar label. Failing that, look for the
specs on the device.
- Unplug devices and transformers when
you're not using them. This method is free
but inconvenient. If you want convenience you
can have it for a few bucks, as the next few
items show...
- For one or two items, get a flip
switch. The one pictured at right is one of
my favorites.
- For a two or more devices that will be on
or off at the same time, use a simple power bar
with a switch. The one pictured at left was
four bucks at Home Depot. Oh, so easy.
 For
several devices that you want to switch
separately, use a power switcher like the $19
GemSound SP-8500, shown at right. I spent
three hours on the Internet looking for such a
product before I could find one, but it was
worth it. This bad boy has eight separate
mutha-fuggin' switches. You can turn individual
devices on and off all day to your heart's
content. I bought two. God I love this
thing.
- For computer systems, you might like the
Bits
Smart Strip. It's a special power
strip that automatically cuts power to all your
peripherals when you turn off your computer. Me,
I prefer the SP-8500 above, because then I can
keep my scanner and printer off while the
computer is on, turning them on only when I
actually need to use them.
- An interesting product called
Bye
Bye Standby ($25) lets you turn power
on and (completely) off using a remote
control. This is handy if you have only a
couple of items to manage, and if the plug isn't
in a convenient place for a switch. They also
have a U.K.
site.
More energy to run the
clock than the device?
When we talk about the "energy to run the
clock" in a microwave or VCR we're not really being
fair, because the standby power does more than just
run the clock. It keeps a microwave ready to
respond to any button you press, and keeps a VCR
ready to respond to the ON button on the remote
control (or your instructions to automatically come
on at a certain time to record a program). But
we're being unfair today, so we'll talk about the
power to run the clock, as though that were the
only thing going on when the device is off.
Okay, so my VCR uses 5 watts when it's "off",
12 watts when it's "on", and 18 watts when it's
actually playing a tape. Let's say I play tapes
for an hour a day, and otherwise it's off.
- ON: 1 hour x 12 watts = 12
watt-hours
- OFF: 23 hours x 5 watts = 115
watt-hours
Yes, the clock uses more energy than the device
itself. Way more.
Is the same true of the microwave? It depends on
how much you use it, and how powerful your
microwave is.
- ON: 10 minutes x 1000 watts =
167 watt-hours
- OFF: 23 hours, 50 minutes x 7
watts = 167 watt-hours
So in this case the clock uses more energy
than the oven if you use the oven for less than 7
minutes a day. (This is an example
because your own microwave likely uses a different
amount of energy when it's on and when it's in
standby. The numbers above aren't true for all, or
even most, microwaves.)
When energy-efficient
appliances aren't
My old Apple Personal Laserwriter
300 was touted as being a modern
energy-efficient appliance. It didn't even
have an power switch! Apple designed it to
automatically go into low-power mode when it
wasn't being used, consuming only five watts of
power.
If you were the kind of person who never
turned off your printer, then this would
definitely save a lot of energy -- most of the
time you'd be using only five watts instead of
several hundred. But if you're the kind of
person who shuts things off when you're done
with them, then all of a sudden this energy
miser is really an energy waster. It sucks five
watts of power 24/7, whether you're using it or
not.
I solved this problem by putting it on a
switchable power strip.
Sample standby power
amounts
- 10.4W - Printer &endash; HP Laser Jet
2200d
- 8.2W - Router &endash; Netgear
DG834PN
- 2.8W - Monitor &endash; Dell 1907FPT,
Elite Group EZX15G
- 1.6W - Phone Charger &endash; Samsung
phone charger for D900
- 0.4W - iPod charger
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