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Saving Electricity

On this page:

Cooking

Mr. Electricity is your guide to saving energy in your home.

Saving Electricity 101:

Start Here
How much it costs / how they charge
What's a Watt / Kilowatt?
How much energy stuff uses
How to measure electrical use

We're recommended by the government of Berks County, PA.

Related sites:

Watt Watt. News about efficiency and conservation, written by readers of the site.

Home Power Magazine. All about renewable energy for the home.

Thin House. Blog about a family committed to cutting its energy use by 80%.

No-Impact Man. Blog about a family striving to have no net impact. (i.e., What little they use, they offset.) Inspirational.

Off-Grid. News and resources about living without being connected to a utility company.

If you like this site, you might also like some of my other sites:

Battery Guide

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How to find the
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Everything you wanna know.

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Ben Folds Five

The rise and breakup of the world's greatest piano pop band.

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How to
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Step-by-step guide for first-time homebuyers.
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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)

How to Not Get
Hit by Cars

An illustrated guide for bicyclists. Might save your life.

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How to save energy when you cook

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) 

Temperature
(degrees F)
Time
Energy Used
Cost

Electric oven

350
1 hr.
2.0 kWh
$0.20

Gas oven, electric ignition

350
1 hr.
0.112 therm
+0.35 kWh
$0.18

Gas oven, pilot

350
1 hr.
0.112 therm
$0.15

Electric oven, convection

325
45 min.
1.39 kWh
$0.14

Toaster oven

425
50 min.
0.95 kWh
$0.10

Crockpot

200
7 hours
0.70 kWh
$0.07

Microwave oven

High
15 minutes
0.36 kWh
$0.04
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.

Gas
Electric

Model

Kenmore 30", #73052
Kenmore 30", #93052

Price

$350
$360

Avg. fuel price

0.0013¢/BTU
($1.30/therm)
9.86¢/kWh

Burner

Energy used

9,000 BTU
2,500 watts

Yearly cost

$14.24
$29.99

Oven

Energy used

18,000 BTU
+ 350 watts
2,600 watts

Yearly cost

$27.93
($24.34 + $3.59)
$26.66

Burner + Oven together

Total yearly cost

$42.17
$56.65

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.

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.


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.]


©1998-2009 Michael Bluejay, Inc. All Rights Reserved. Unauthorized reprinting is prohibited
All advice is given in good faith. We're not responsible for any errors or omissions. Electricity can kill you; if you're not competent to work on your electrical wiring then hire a professional to do it.
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