If you live in a typical U.S. home, your appliances-electronics are responsible for about 20% of your energy bills. These appliances-electronics include the following:
•Clothes washers and dryers
•Home audio equipment
•Refrigerator and freezers
•Room air conditioners
•Televisions, DVD players, and VCRs
In late 2009 or early 2010, you can receive rebates to purchase new ENERGY STAR-qualified appliances when you replace your used appliances.
Shopping for Energy-Efficient Appliances-Electronics
When it comes to shopping for and comparing energy-efficient appliances-electronics, look for the ENERGY STAR® and EnergyGuide labels.
ENERGY STAR Label
ENERGY STAR labels appear on appliances-electronics that meet strict energy efficiency criteria established by the U.S. Department of Energy and U.S. Environmental Protection Agency. The ENERGY STAR labeling program includes most appliances-electronics except for stove ranges and ovens.
In late 2009 or early 2010, you can receive rebates to purchase new ENERGY STAR-qualified appliances when you replace your used appliances. Learn more:
The Federal Trade Commission requires EnergyGuide labels on most home appliances (except for stove ranges and ovens), but not home electronics, such as computers, televisions, and home audio equipment. EnergyGuide labels provide an estimate of the product's energy consumption or energy efficiency. They also show the highest and lowest energy consumption or efficiency estimates of similar appliance models.
Estimating Appliances-Electronics Energy Use
If you're trying to decide whether to invest in a more energy-efficient appliance or you'd like to determine your electricity loads, you may want to estimate appliances-electronics energy consumption.
Formula for Estimating Energy Consumption
You can use this formula to estimate an appliance's energy use:
(Wattage × Hours Used Per Day) ÷ 1000 = Daily Kilowatt-hour (kWh) consumption
1 kilowatt (kW) = 1,000 Watts
Multiply this by the number of days you use the appliance during the year for the annual consumption. You can then calculate the annual cost to run an appliance by multiplying the kWh per year by your local utility's rate per kWh consumed.
Note: To estimate the number of hours that a refrigerator actually operates at its maximum wattage, divide the total time the refrigerator is plugged in by three. Refrigerators, although turned "on" all the time, actually cycle on and off as needed to maintain interior temperatures.
(200 Watts × 4 hours/day × 120 days/year) ÷ 1000
= 96 kWh × 8.5 cents/kWh
Personal Computer and Monitor:
(150 Watts × 4 hours/day × 365 days/year) ÷ 1000
= 394 kWh × 8.5 cents/kWh
You can usually find the wattage of most appliances stamped on the bottom or back of the appliance, or on its nameplate. The wattage listed is the maximum power drawn by the appliance. Since many appliances have a range of settings (for example, the volume on a radio), the actual amount of power consumed depends on the setting used at any one time.
If the wattage is not listed on the appliance, you can still estimate it by finding the current draw (in amperes) and multiplying that by the voltage used by the appliance. Most appliances in the United States use 120 volts.
Larger appliances, such as clothes dryers and electric cooktops, use 240 volts. The amperes might be stamped on the unit in place of the wattage. If not, find a clamp-on ammeter—an electrician's tool that clamps around one of the two wires on the appliance—to measure the current flowing through it.
When measuring the current drawn by a motor, note that the meter will show about three times more current in the first second that the motor starts than when it is running smoothly.
Many appliances continue to draw a small amount of power when they are switched "off." These "phantom loads" occur in most appliances that use electricity, such as VCRs, televisions, stereos, computers, and kitchen appliances.
Most phantom loads will increase the appliance's energy consumption a few watt-hours. These loads can be avoided by unplugging the appliance or using a power strip and using the switch on the power strip to cut all power to the appliance.
Typical Wattages of Various Appliances
Here are some examples of the range of nameplate wattages for various household appliances:
•Aquarium = 50–1210 Watts
•Clock radio = 10
•Coffee maker = 900–1200
•Clothes washer = 350–500
•Clothes dryer = 1800–5000
•Dishwasher = 1200–2400 (using the drying feature greatly increases energy consumption)
•Dehumidifier = 785
•Electric blanket- Single/Double = 60 / 100
•Ceiling = 65–175
•Window = 55–250
•Furnace = 750
•Whole house = 240–750
•Hair dryer = 1200–1875
•Heater (portable) = 750–1500
•Clothes iron = 1000–1800
•Microwave oven = 750–1100
•CPU - awake / asleep = 120 / 30 or less
•Monitor - awake / asleep = 150 / 30 or less
•Laptop = 50
•Radio (stereo) = 70–400
•Refrigerator (frost-free, 16 cubic feet) = 725
•19" = 65–110
•27" = 113
•36" = 133
•53"-61" Projection = 170
•Flat screen = 120
•Toaster = 800–1400
•Toaster oven = 1225
•VCR/DVD = 17–21 / 20–25
•Vacuum cleaner = 1000–1440
•Water heater (40 gallon) = 4500–5500
•Water pump (deep well) = 250–1100
•Water bed (with heater, no cover) = 120–380
When to Turn Off Personal Computers
If you're wondering when you should turn off your personal computer for energy savings, here are some general guidelines to help you make that decision.
Though there is a small surge in energy when a computer starts up, this small amount of energy is still less than the energy used when a computer is running for long periods of time. For energy savings and convenience, consider turning off
•the monitor if you aren't going to use your PC for more than 20 minutes
•both the CPU and monitor if you're not going to use your PC for more than 2 hours.
Make sure your monitors, printers, and other accessories are on a power strip/surge protector. When this equipment is not in use for extended periods, turn off the switch on the power strip to prevent them from drawing power even when shut off. If you don't use a power strip, unplug extra equipment when it's not in use.
Most PCs reach the end of their "useful" life due to advances in technology long before the effects of being switched on and off multiple times have a negative impact on their service life. The less time a PC is on, the longer it will "last." PCs also produce heat, so turning them off reduces building cooling loads.
For cost effectiveness, you also need to consider how much your time is worth. If it takes a long time to shut down the computer and then restart it later, the value of your time will probably be much greater than the value of the amount of electricity you will save by turning off the computer multiple times per day.
Power-Down or Sleep Mode Features
Many PCs available today come with a power-down or sleep mode feature for the CPU and monitor. ENERGY STAR® computers power down to a sleep mode that consume 15 Watts or less power, which is around 70% less electricity than a computer without power management features.
ENERGY STAR monitors have the capability to power down into two successive "sleep" modes. In the first, the monitor energy consumption is less than or equal to 15 Watts, and in the second, power consumption reduces to 8 Watts, which is less than 10% of its operating power consumption.
Make sure you have the power-down feature set up on your PC through your operating system software. This has to be done by you, otherwise the PC will not power down. If your PC and monitor do not have power-down features, and even if they do, follow the guidelines above about when to turn the CPU and monitor off.
Note: Screen savers are not energy savers. Using a screen saver may in fact use more energy than not using one, and the power-down feature may not work if you have a screen saver activated. In fact, modern LCD color monitors do not need screen savers at all.