Improving energy efficiency and conservation around the house requires a certain attention to detail. There are a multitude of electronic appliances that populate the modern home. Knowing how many watts of electricity each appliances uses is a key step toward reducing your electricity consumption. You’ll know which ones to trade in for newer, more efficient models- creating a general awareness and knowledge that will aide in all of your energy conserving endeavors.
Figuring out how many watts of electricity an appliance uses is typically very easy. It is generally printed right on the device. It will either be stamped on it somewhere or printed on a nameplate that is usually affixed to the back.
If the number of watts is not printed on the device, then look for the current, in amperes (A), and voltage (V). Most appliances, from stereos to toaster ovens, use 120 volts (the maximum voltage for a standard outlet). Larger appliances, such as clothes dryers, may use 240-volt outlets. To find a unit’s wattage, simply multiply the amps and the volts. For example, a device drawing 5.0 A at 120 volts is using 600 Watts of electricity.
In the typical home, water heaters use by far the most amount of electricity, drawing 4500-5500 watts when running. The clothes dryer, dishwasher, and vacuum cleaner are also big electricity users. Just remember that an individual appliance’s cost to each household is different based on how much the appliance is used. For example, a laptop computer typically uses only 50 W of electricity (somewhat less in sleep mode) and a dryer may use 5000. But if the computer is left on 24 hours a day, and the dryer is rarely used because you dry your clothes outside on a line, then suddenly the smaller, more efficient computer has the higher cost in electricity. Being energy efficient is as much about lifestyle and the way we use the products we purchase as it is about the products themselves.
Bear in mind that the wattage listed on an electronic device is its peak level of consumption. That is to say that electronics such as stereos, with volume controls, may not be drawing the maximum number of watts at all times. It all depends on the setting.
When evaluating the energy efficiency of any device, it is also important to factor in “phantom” loads, or the small amount of electricity that a device draws, even when it is switched off. Televisions, stereos, computers, all such devices carry phantom loads. These are small amounts but can really add up, especially considering the number of appliances in the average home. To avoid this issue, either unplug appliances when unused, or plug several into a power strip and then switch the strip off when the group is not in commission. The power strip method is an excellent choice for computer desks and home entertainment centers, where all components are typically used or shut off at the same time.
For more information on calculating electricity consumption and cost, including a list of common wattages for household appliances, see the U.S. Department of Energy’s Office for Energy Efficiency and Renewable Energy (EERE) website.