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Saving Electricity |
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Heating |
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26,500 watts |
Elec. furnace, 2000sf, cold climate |
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7941 watts |
Elec. furnace, 1000sf, warm climate |
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1440 watts |
Electric space heater (high) |
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900 watts |
Electric space heater (medium) |
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600 watts |
Electric space heater (low) |
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750 watts |
Gas furnace (for the blower) |
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1100 watts |
Waterbed heater |
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450 watts |
Waterbed heater (avg. 10 hrs./day) |
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Cooling |
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3500 watts |
Central Air Conditioner (2.5 tons) |
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1440 watts |
Window unit AC, huge |
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900 watts |
Window unit AC, medium |
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500 watts |
Tiny-ass window unit AC |
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750 watts |
Central AC fan (no cooling) |
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More efficient cooling |
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400 watts |
Evaporative cooler |
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350 watts |
Whole-house fan |
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100 watts |
Floor or box fan (high speed) |
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90 watts |
52" ceiling fan (high speed) |
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75 watts |
48" ceiling fan (high speed) |
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55 watts |
36" ceiling fan (high speed) |
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24 watts |
42" ceiling fan (low speed) |
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Major appliances |
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4400 watts |
Clothes dryer (electric) |
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Washing machine |
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3800 watts |
Water heater (electric) |
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200-700 watts |
Refrigerator (compressor) |
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57-160 watts |
Refrigerator (average) |
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3600 watts |
Dishwasher (washer heats water) |
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2000 watts |
Electric oven, 350°F |
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1178 watts |
Electric oven,
self-cleaning mode |
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1200 watts |
Dishwasher (dry cycle) |
| 200 watts |
Dishwasher (no water heating or drying) |
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Lighting |
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60 watts |
60-watt light bulb (incandescent) |
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18 watts |
CFL light bulb (60-watt equivalent) |
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5 |
Night light |
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0.5 |
LED night light |
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Computers (see more about electrical use of computers) |
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150-340 watts |
Desktop Computer & 17" CRT monitor |
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1-20 watts |
Desktop Computer & Monitor (in sleep mode) |
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90 watts |
17" CRT monitor |
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40 watts |
17" LCD monitor |
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45 watts |
Laptop computer |
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Televisions & Videogames |
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191-474 watts |
50-56" Plasma television |
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210-322 watts |
50-56" LCD television |
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150-206 watts |
50-56" DLP television |
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188-464 watts |
42" Plasma television |
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91-236 watts |
42" LCD television |
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98-156 watts |
32" LCD television |
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55-90 watts |
19" CRT television |
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45 watts |
HD cable box (varies by model) |
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194 watts |
PS3 |
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185 watts |
Xbox 360 |
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70 watts |
Xbox |
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30 watts |
PS2 |
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18 watts |
Nintendo Wii (source) |
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Other |
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1440 watts |
Microwave oven or 4-slot Toaster |
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900 watts |
Coffee maker |
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800 watts |
Range burner |
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4 watts |
Clock radio |
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3 watt-hours |
Total power stored by an alkaline AA battery. This is to put batteries into perspective. If you could power your clock radio with a AA battery, it wouldn't even last an hour. We have more on batteries on our Guide to Household Batteries. |
| Wattage varies from model to model! Figures
above are examples.
See How to Misquote this Website. Data for specific models of appliances is available at the Power Consumption Database. |
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U.S. household energy
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A little farther down is a chart showing the relative use of various appliances. (DoE)
Note that this doesn't really jibe with the pie chart from the
DoE. (Refrigerators and appliances use different amounts in the
different charts.) If I can ever find the time, I'll try to make
my own chart.
Here are some other websites that give sample costs for various household items considering how much those items are used:
At far right is a table listing examples of the wattage of common household appliances.
Appliances that create or remove heat use the most electricity. In the table at right, appliances that make things hot are listed in red and ones that make things cold are listed in blue. As you can see, together they dwarf everything else on the list.
Don't like my table? Here's another table from GeneratorSales.com. Databases which list power data for specific models of products include the Power Consumption Database, and the super-slow More Energy Savings.

Remember that electrical usage varies from model to model, and that the tables on this site are just examples. (See how to misinterpret this website.)
If the label only gives the number of amps and not the number of watts, then just multiply the amps by 120 to get the number of watts. (Amps x Volts = Watts, and most U.S. electricity is ~120 volts. So a hot plate rated at 6 amps uses 6 x 120 = 720 watts, on the highest setting. Most other countries use 240 volts instead of 120, so outside of North America and Japan use 240 instead of 120 in your calculations.) Note that if a device is powered by a transformer (one of those great big plugs), then the transformer has converted the electricity from AC to DC, so you need to multiply by the DC voltage, not the AC voltage of 120. For example, if the device says "INPUT 9V, 0.5A", then that's 9 volts x 0.5 amps = 4.5 watts.
You may have noticed that appliances may be labeled 110, 115, or 120 volts. U.S. appliances are actually designed to accept a range of voltages, between 110-120 volts, and the exact voltage coming out of your electrical socket can vary depending on conditions at the power plant and in your own home. Let's just agree that when we say 120 volts, we understand that it's actually a range from 110-120. And just use 120 for your calculations (unless you're outside of North America or Japan, in which case you probably have 220-240 volts).
Your device might actually list a huge voltage range, like 100-240V. That just means that it will work with any country's voltage. For your calculations, use the voltage for the country where you're plugging the device in.
Some important caveats:
Exercise: Pretend there's an energy crisis and they start rationing electricity. You're given a bonus of 1000 watt-hours of electricity to use because you won a special drawing. If you're choosing between using your stereo or your central air conditioner, how long could you run each? Assume that your stereo uses 30 watts and your AC uses 3500 watts. (see answer)
Exercise: The power adapter on your laptop computer says its output is 24V and 1.875 amps. The input specs aren't listed for some reason. What's the maximum number of watts your computer could ever use? (see answer)
Energy-saving strategies
Here's how much various strategies can save you.
Easy Strategies
Strategy
Up front cost Savings per year (1) Use space heaters to heat only the rooms you're in, (rather than a central system that heats the whole house), and turning off the heat when you're not home.
$80 $1023 (2) Use ceiling fans instead of the air conditioner $100
if you don't already have ceiling fans$438 (3) Turn off lights you're not using $0 $274 (4) Use a clothesline or a laundry rack instead of a dryer $20 $196 (5) Sleep your computer when you're not using it $0 $178 (6) Wash laundry in cold water instead of hot or warm none $152 (7) Turn off a single 100-watt light bulb, from running constantly $0 $131 (8) Replace ten 60-watt light bulbs with compact fluorescents $32 $123 Total $232
once$2515
every yearAggressive Strategies (9) Replace top-loading washer with front-loading washer $500 $112 (10) Replace 1990 fridge with newer model $300 $68 Total $800
once$180
every yearAssumptions:
Sample electrical rate of 15¢/kWh.
(1) One 5000-watt central system, always on, running 40mins/hr. for four months, vs. two 1500-watt heaters running 8 hours a day for four months.
(2) A 2.5-ton, 3500-watt AC 24 hours a day (15 mins/hr) for five months, vs. two 48" ceiling fans on high (75 watts each), 12 hours/day.
(3) Five 100-watt light bulbs on for 10 hours a day when they don't need to be.
(4) 50¢/load as per the clothes dryers page, 7.5 loads a week.
(5) Computer on for 24 hrs/day @ 160 watts, vs. sleeping 21 hrs/day @ 5 watts
(6) Electric water heater; 7.5 loads/week.
(8) CFL's are 15 watts, lights run 5.5 hours a day.
(9) 1/3 hot washes, 2/3 warm washes, water heated electrically, electric dryer, 7.5 loads/week. Includes water costs.
(10) Replacing a 900 kWh/year top-freezer model with a 450 kWh/year top-freezer model
» Now see how to measure electrical use »
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 useMr. Electricity is your guide
to saving energy in your home.General
- Electricity Myths
- Using elec. when off?
- Why is my bill so high?
- Capacity of an Outlet
- Electric Meters
- General Questions
Specific Appliances
Environment
- Carbon footprint calculator
- Carbon offsets
- Solar Power
- Bicycle Power
- Alternative Energy
- Climate change
Special Topics
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©1998-2010 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.Contact | Misquoting this Website | My home page If you liked this site, you might like some of my other sites:
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