Mr. Electricity is your guide to saving energy in your home.
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If you like this site, you might also like some of my
other sites:
Battery
Guide
Which battery is best? We cover
rechargeable and alkaline batteries to show you what's hot,
what's not, and the best way to charge them. (visit
now)
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The
Military Budget as Cookies
This excellent animation from TrueMajority shows in
graphic detail (using Oreo cookies) how ridiculously, large
the military budget is, and how we could solve many domestic
problems with a modest 12% cut. A must-see. (watch
it now)
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How
to save energy when you
cook
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Let me be perfectly clear:
Most
people can't save much energy by
changing their cooking methods,
compared to other ways you can
save energy. You'll
save a lot more energy by:
I provide this page anyway not
because it's really useful but
because so many people are
curious about it.
How
much do various baking methods
cost? (oven-style
cooking)
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Temperature
(degrees F)
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Time
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Energy
Used
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Cost
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Electric
oven
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350
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1 hr.
|
2.0 kWh
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$0.20
|
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Gas oven,
electric ignition
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350
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1 hr.
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0.112 therm
+0.35 kWh
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$0.18
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Gas oven,
pilot
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350
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1 hr.
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0.112
therm
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$0.15
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Electric oven,
convection
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325
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45 min.
|
1.39
kWh
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$0.14
|
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Toaster
oven
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425
|
50 min.
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0.95
kWh
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$0.10
|
|
Crockpot
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200
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7 hours
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0.70
kWh
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$0.07
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Microwave
oven
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High
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15
minutes
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0.36
kWh
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$0.04
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From
Citizens
Campaign for the
Environment,
and Home
Energy
1993
and 2001.
Assumes $0.10/kWh for electricity
and $1.30/therm for
gas
Note from the second
row in the table that gas
ovens use electricity!
Electric ignition ovens run a
350-watt glow bar to keep the
gas flame going. (more...)
APS has a good table
showing the
efficiency of gas, electric,
and microwave ovens. The
efficiency doesn't tell you
the cost, though, because
different energy sources are
charged at different
rates.
Note that for someone
baking three hours a week,
the cheapest baking method
saves only $2.06/mo. compared
to the most expensive
method. This underscores
my point that focusing on
cooking methods is not the way
to save electricity, and you
should look at heating,
cooling,
lighting,
and laundry
instead.
Gas vs.
Electric Stoves /
Ovens
In general, gas is
cheaper than electric for
cooking, but there are
several caveats:
- "Cheaper" is a
relative term. The
average typical savings for
gas over electric cooking
is only $18/yr.
- Electric could be
cheaper where you live, or
in the future. The cost
of natural gas has
skyrocketed recently. Gas
used to be a much better
deal than it is now. Also,
gas could be more expensive
than electric in your area
right now.
- Running a gas line
negates the savings. If
you don't have already have
a gas line running to the
kitchen, the cost of having
one installed could easily
be more than you'd save by
switching to gas, even
after several years.
- The monthly gas
charge negates the savings.
If you don't already
have gas service, getting
gas service just to power a
gas stove will likely wind
up costing you way more
than continuing to use an
electric stove. That's
because you'll have to pay
~$10/mo. or so as a
"customer charge", just for
the privilege of being a
gas customer.
- Gas has other
drawbacks compared to
electric. For starters,
gas is dangerous
because it's combustible.
Remember the Hindenberg?
Imagine a similar explosion
in your house. True, most
people's kitchens don't
blow up, but some of
them certainly do. Next,
breathing the products
of gas combustion is
decidedly unhealthy.
Electricity doesn't have
that drawback. I choose
electric over gas for that
reason alone.
The problem with air
pollution from gas
ovens/stoves is so bad
that I found this in a
Whirlpool oven manual from
2003: "The health of some
birds is extremely sensitive
to the fumes given off [by
the oven]. Exposure to the
fumes may result in death to
certain birds. Always move
birds to another closed and
well ventilated room."
While the problem is more
serious for birds it exists
for people, too. A study
commissioned by the Air
Resources Board of California
showed that gas
ovens generate unhealthy
levels of combustion
byproducts like carbon
monoxide and nitrogen dioxide.
(It also showed that the
self-cleaning mode generated a
lot of indoor air pollution,
whether it was a gas or an
electric oven.) If you do use
gas, the Children's Health
Environmental Coalition has a
list of ways
to reduce gas pollution in
your home.
Cost of gas vs.
electric. The following
table compares the cost of
operating a gas vs. electric
stove/oven.
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Gas
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Electric
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Model
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Kenmore 30",
#73052
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Kenmore 30",
#93052
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Price
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$350
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$360
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Avg. fuel
price
|
0.0013¢/BTU
($1.30/therm)
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9.86¢/kWh
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Burner
|
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Energy used
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9,000
BTU
|
2,500
watts
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Yearly
cost
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$14.24
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$29.99
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Oven
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Energy used
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18,000
BTU
+ 350 watts
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2,600
watts
|
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Yearly
cost
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$27.93
($24.34
+
$3.59)
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$26.66
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Burner
+ Oven
together
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Total yearly
cost
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$42.17
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$56.65
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Prices
from Sears.com in
July 2006. Fuel rates
are U.S. national
averages in spring
2006; see more on
electricity
prices
and gas
prices.
Yearly costs assumes
using two burners for
ten minutes a day
each on high, and the
oven for two hours a
week.
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So gas is cheaper for
stovetop, and electric is
cheaper for oven baking.
Part of the reason is that in
modern gas ovens with electric
igniters, the igniters stay on
even after the oven is
lit.
Microwave ovens are
almost as cheap as running an
electric burner. For
baking, microwave ovens
and crockpots are cheaper than
both electric and gas
ovens.
There's also a new kind of
stovetop cooking called
induction
cooking, but I have no
good data and no unit to
test.
Tips to
save on energy costs when
cooking
- Remember that you can't
save much energy by changing
your cooking methods.
Cooking uses a fraction of
total household energy
compared to things like
heating, cooling, and
lighting. The tips below do
work, but the savings is
minimal.
- Use a crockpot and a
microwave oven for baking.
These are the cheapest ways to
bake.
- Open the oven door only
when necessary. Oven
temperature drops 25-30
degrees every time you open
the door. Getting an oven with
an oven light and a glass
window in the door will let
you check on your food without
opening the door.
- Don't put aluminum foil
on the bottom of a gas oven to
catch drippings. The foil
blocks the heat that the oven
is trying to produce. (It's
fine to put foil in an
electric oven, as long as you
leave the heating elements on
the side exposed.)
- Use glass and ceramic
pans when baking. They
retain heat better than metal
pans and allow you to lower
the baking temperature by 25
degrees.
- Isolate the
kitchen. If the oven is on
for an hour or more, close
doors leading to the kitchen
to keep the kitchen from
heating up the rest of the
house. If you have a stove
exhaust fan, use it.
- Don't use pilot lights
on gas burners. Pilot
lights not only waste gas
24/7, they add heat to your
home. Eliminating pilot lights
means lower costs for cooling
since you'll run the A/C less.
Going pilotless will use 40%
less gas than normal.
(source)
If your existing stove already
has pilot lights, turn them
off and use a clicker-lighter
to light the burner when
you're cooking. (Turning them
off requires tightening the
set screw. You can't just blow
the pilot out, because then
gas will still be leaking out
the unlit pilot hole.)
Getting a new oven with
electric ignition instead of
pilot lights will make it easy
to save gas on the burners,
but you'll give up that
savings when using the oven
because the electric igniter
runs the whole time the oven
is on. (See the table at the
top of this page.)
Below are questions I've
received and answered about how
saving energy when cooking.
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Questions about
saving energy when cooking
When my wife
wants a cut of hot water she heats up a
cup of cold water in the microwave. I keep
telling her that it is uses less power
from a financial standpoint to heat the
water in a teapot on our gas stove. She
doesn't believe me. Who is
right?
-- Anonymous,
Nov. 2004
There is no such thing as
"using less power from a financial
standpoint". You can use less power, or
you can pay less money, but they're two
different things. Method A might use
less power than Method B but could
still cost more if the kind of fuel it
uses were more expensive. Decide which
issue you want to argue with your wife
about: cost or efficiency. They're not
the same thing.
According to Home
Energy Magazine, gas stoves are
only 40% efficient compared to a
microwave's 55%. But the gas stove is
cheaper to run because gas is cheaper
than electricity. The microwave uses
less power, but the gas stove is
cheaper financially.
However, focusing on this won't save
you an appreciable amount of money
because the raw cost of using one
method vs. another isn't that great.
You'd see more savings by replacing one
light bulb with a CFL or turning off
the air conditioner on occasion.
Which uses
less electricity: boiling water with an
electric burner or boiling it in a
microwave oven?
-- Anonymous,
Nov. 2004
For all intents and purposes
the energy used is the same. I boiled
two cups of 86-degree water in a GE
microwave oven (Model JS1533BV001,
1995) and it used 0.087 kWh. Boiling it
in a pot on an electric burner used
0.095 kWh. While there's a difference
it's not statistically significant,
especially given how crude my testing
methods were. Even assuming that these
figures are completely accurate, then
boiling two cups of water every day for
a year would use only 2.92 kWh extra
with the electric burner, or less than
$0.30 for the whole year.
While looking at this issue might be
interesting it's not useful for saving
electricity. Whichever is more
efficient, the difference isn't going
to be that great. Focusing on this
won't save you an appreciable amount of
energy. You'd save more energy over the
year by replacing one light bulb with a
CFL or turning off the air conditioner
for an hour. (Not an hour a day, one
hour at some point over the whole
year.)
[Note: Since I originally
answered this question, a reader
pointed us to Home
Energy Magazine's report on boiling
water using various methods, which says
that electric burners use 25% less
electricity than microwaves, though
their chart shows that the energy use
is about the same. They also point out
that if you boil only a mug of water in
the microwave vs. a whole kettle on the
stovetop, the microwave is going to be
cheaper. Again, this is academic,
because the difference between one
method vs. the other pales in
significance to the savings you'd get
by using CFL light bulbs or turning off
your AC for a day.]
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