PUBLISHED: 6:39 AM on Wednesday, May 28, 2008
Calculating energy-efficiency of small kitchen appliances
How much does it cost to operate your electrical appliances? The answer depends on many factors, including the number and types of appliances you use, how long you use them, and the price of electricity.

The cost of operating an electrical appliance is calculated using these three factors:

1. The number of watts the appliance uses.

2.The number of hours the appliance is used.

3.The cost you pay for one kilowatt-hour (kWh) of electricity. (A kilowatt-hour is 1,000 watts of electricity used for one hour).

To calculate the cost of operating an appliance, multiply the wattage of the appliance by the approximate number of hours you operate the appliance (the wattage of an appliance is usually listed on the appliance). Next, divide by 1,000; this will give you the number of kWhs the appliance uses. Finally, multiply the kWh use by the cost per kWh as shown on your electric bill.

For example: An oven is rated at 2,660 watts and operated an average of 15 hours per month. The 15 hours are equivalent to about four uses of the oven per week.

1. Multiply 2,660 watts by 15 hours (2,660 x 15 = 39,900 watt-hours)

2.Divide by 1,000 (39,900 /1,000 = 39.9 kWh)

3.Multiply the kWh by the price of electricity. We'll round out the kWh to 40 and use $0.561 per kWh (current electricity rate in Juneau) for the price: (40 kWh x $0.561 = $22.40). The oven costs approximately $21.60 a month to operate.

Using small kitchen appliances makes energy-savings sense. When using the microwave oven, it may mean experimenting on length of cooking time as to personal tastes. For instance, when using the conventional method of cooking brown rice on a 8-inch range burner, it takes about 45 minutes and uses 2,400 watts. Cooking rice in the microwave takes about the same amount of time (45 minutes) yet uses less energy. If your diet consists largely of rice dishes, a rice cooker may be a good investment. A quick search on the Internet found rice cookers that use 33 watts.


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Appliance Watts Avg. hour KWh used Avg. cost

Crock pot 100 20 2 $1.25

Elec frying pan 1,150 15 17 $9.54

Microwave oven 1,400 15 21 $11.78

Range: Oven 2,660 15 40 $22.40

Large burner (8in) 2,400 15 36 $20.20

Small burner (6in) 1,300 15 19 $10.66

•rates based on monthly usage / info provided by Sonja Koukel

When boiling water is needed for food preparation, use the microwave. In preparing spaghetti, I brought the water to a boil in the microwave and then transferred it to a pot on the stovetop. This method decreased the cooking time on the range.

A surprise to some folks is the low wattage used by crock pots. Since crock pots are slow cookers that use energy for 8-10 hours it easily can be assumed that they are not energy efficient. However, these appliances cook with 100 watts. As you can see from the comparison table, cooking a few meals using a crock pot can result in a huge savings in your electricity usage.

A couple of years ago, I purchased a 8-quart pressure cooker saucepan. Although the saucepan is used on the range, using 2,400 watts, the cooking time is extremely short. For instance, I cooked a 3-inch thick salmon steak that was frozen solid. In fact, I took the fish out of the chest freezer, seasoned it with dill weed, lemon pepper and salt, and put it in the saucepan.

From start to finish, the fish took about 10 minutes to reach an internal temperature of 145? F. The salmon was flaky and moist. In comparison, a

thawed 3-inch thick salmon steak would take close to an hour to bake in the oven using 2,660 watts.

I've also used the pressure cooker saucepan to prepare frozen halibut (4 minutes) and a two-pound pork loin roast (40 minutes). Pressure cooker saucepans can be used to prepare a variety of dishes, including soups, vegetables, and legumes.

If it's necessary to use the range or oven, here are some tips for conserving energy:

• Match the pan size to the element size. For example, when using an electric range, a 6-inch pan on an 8-inch burner will waste over 40 percent of the heat produced by the burner.

• Keep the burner pans clean and shiny so they reflect heat up to the cookware.

• Use high-conductivity materials. For instance, copper-bottom pans heat up faster than regular pans. And, professional chefs consider cast-iron pans to be precision cooking tools, as these dependable pans enable precise control of cooking temperatures. Their heat retention qualities allow for even cooking temperature without hot spots. Cast-iron pans can be used on top of the stove or in the oven. Additionally, glass or ceramic pans are better than metal for use in the oven. When using this cookware, you can turn down the temperature about 25-degrees and cook foods just as quickly.

•Defrost frozen foods in the refrigerator. The exception is when using a pressure cooker saucepan and the directions specify using frozen products.

• Don't preheat the oven unless specified in the recipe. Here, you might experiment. I baked cinnamon rolls in a cold oven where preheating was suggested in the directions. The rolls took a bit longer to bake, but there was no loss of product quality.

• To improve air flow, don't lay foil on the racks and stagger multiple pans.

• Grill instead of bake.

• Turn off the heat just before the cooking is finished to prevent overcooking. Use a food thermometer to ensure correct internal temperature.

• Plan ahead and cook double portions.

Although Juneau has been at the forefront of energy conservation since April 16, it is understood and appreciated that all communities served by the Capital City Weekly are faced with high energy rates.

Cooperative Extension is poised to gather information and provide resources for all Alaskans. Therefore, if there are specific questions or concerns you have about energy savings techniques, or if you have tips to share, I invite you to contact me. In the meantime, get more information from the Juneau district office (907-796-6221) or

Dr. Sonja Koukel is the Health, Home & Family Development Program educator for the Cooperative Extension Service UAF Juneau District.