Ever wanted to have an approximate idea of what your energy bill is going to be before it comes in? In this article we will try to go into detail on how you can have a good estimate of energy consumption of your house via its appliances.
Formula for Energy Consumption:
We will try to make this as painless as possible, however, you will have to use a formula (we will you how to set it up in an excel sheet later)
(Wattage x Hours Used Per Day / (divided) 1000 = Daily Kilowatt-hour (kWh) consumption
(1 kilowatt (kW) = 1,000 Watts)
Next, you need to multiply this number by the approximate number of days you use the appliance during the year for the annual consumption. Then multiply this number by your local utility’s rate per kWh consumed.
Tip: refrigerators: take the maximum wattage, and (divide) the total time the refrigerator is plugged in by 3. Because, refrigerators cycle on/off on a consistent basis.
Here are a few examples:
Window Fan:
(200 Watts x 4 hours/day x 120 days/year) / 1,000
= 96 kWh x 8.5 cents/kWh
= $8.16 per year
Personal Computer & Monitor
(120 + 150 Watts x 4 hours/day x 365 days/year) / 1,000
=394 kWh x 8.5 cents/kWh
= $33.51
Where can you find Wattage at?
Usually, the wattage can be found on most appliances either stamped on the bottom or the back and or on its nameplate. This wattage listed is the MAXIMUM power drawn by the appliance. Though, you need to take into consideration what type of appliance it is. For example, if it’s a radio and or speakers the ‘volume’ will determine how much watts/electricity it’ll need to operate.
I can’t find the wattage?
If you can’t find the wattage, best bet is to either Google your appliance and see if you can find it that way. If you can’t you can always make an educated guess by following these guidelines. Most appliances in the US use approximately 120 volts. Larger appliances (dryers & stoves) use 240 volts. Also, remember that 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.