We’ve written before about the importance of purchasing energy efficient appliances. Now let’s look at exactly how much energy your appliances use and how much money that translates to on your energy bills. Here’s how to find that information and how you can use it to increase your home’s energy efficiency.
How to determine how much energy your appliances use:
- If you have an Energy Guide label on your appliance(s), it should include information about the average energy consumption and cost to operate that specific appliance.
- You can install a whole house energy monitoring system to easily keep track of all of your energy use.
- If purchasing a unit for your entire home seems like too much, you can use an electricity usage monitor to determine the energy consumption of your individual appliances. These devices function in a very similar way to household energy monitoring systems, except they work on one electrical outlet only, providing information on whatever device is plugged in.
- Lastly, it is possible to manually calculate your appliance’s annual energy consumption based on common usage patterns and information found on your appliances.
How to calculate annual electricity consumption and costs:
You will need the following information to calculate your annual electricity consumption and costs:
- The amount of time your appliances have run
- The wattage of the appliance
- Your utility rate in kilowatt hours (kWh)
Multiply the time by the wattage, then multiply that by your utility rate in kWh (kilowatt hours). This will give you the actual cost. Here is a simple formula for remembering what you’ll need:
T x W x R = Annual Cost
T = time your appliances have run
W = wattage of appliances
R = utility rate from your electric company measured in kilowatt hours
Here are a few additional tips for gathering that information:
- Estimate the number of hours—Short of keeping a detailed log of each time you use electricity (a job better suited for one of the devices described above), you can make an educated estimate about your energy usage during a given period of time.
When determining how long your refrigerator has been used, divide the total amount of time it was plugged in by three. While your refrigerator might always be plugged in, it actually cycles on and off during the day in order to maintain the desired internal temperature.
- Find wattage information on your appliance—Most appliances have technical information physically stamped onto the appliance, usually on a nameplate in the back or on the bottom. The wattage information will appear as a range of numbers representing the minimum and maximum amounts of wattage that are possible for the device, depending on usage. For example, a microwave might use different amounts of energy based on cooking settings and would therefore require a wattage range instead of one static number. When doing your rough calculations, try to make as accurate a decision as possible. If you get stuck, try using a number right in the middle of the wattage range provided.
You may also find this information in documentation accompanying your appliances, or go online to research whatever information you desire.
Finally, if all of these options fail you for finding wattage information, you can calculate it manually. To do so, multiply voltage times electrical current draw (in amperes) to find wattage. You can find this information in the same places described above.
V (voltage) x C (electrical current draw, in amperes) = W (wattage of the appliance)
The average voltage on American appliances is 120 volts, though many larger appliances like clothing washers and dryers or ovens are commonly 240 volts.
If you are simply looking to get a rough idea of how much energy your appliances use, you can refer to the helpful guides provided below. There, you will find common information about the average appliance’s energy usage.