Depending on where you live, you might be using your heating unit much more now to stay warm during winter season. If you’re an unfortunate soul that has an all-electric HVAC system, you might also start to notice your electric bill creeping up. But regardless of what season it is or weather you have a gas furnace, have you ever wondered how you end up owing what you owe for the monthly electric bill?
You probably receive a bill with the balance due and the total energy you consumed. It might have some graph comparing your energy usage to your neighbors to make you feel bad on how much your over spending compared to them. Then finally in some corner you will see the the payment due date. But what does this all even mean? Do you actually know how you consumed that energy? What if your neighbor is stealing your power with that 100ft long extension cord? You know you’ve suspected it before!
Fortunately there is a way for you to figure this out. Similar to grocery shopping, where the receipt lists every single item with its cost, then the total dollar amount at the bottom, you can do the same for your electric bill. Since the bill is basically the electric energy you consumed, then it would make sense that all your electrical devices contribute to that bill. At some part of the bill, you will have a total energy consumed, very likely in the form of kilowatts per hour or kWh. Watts is a measurement of power, just like horsepower is used to measure engine power.
Going on with our grocery list analogy, a list of each and every single electrical device that is used throughout the month would add to that total payment due. Just like a good piece of steak will have a sticker with it’s price, it will also tell you the price per pound. Similarly, the electric bill will tell you the cost per kWh. The national average is about 13 cents per kWh. If you don’t see your total rate on the bill, just divide the total cost by the total kWh. So if your bill is $100 and you used 800kWh, your rate is $0.125 per kW/h.
With the energy rate known, now you only need two more things:
- the power the device consumes in watts
- the time the device is used in hours
For example a classic incandescent light bulb, although cheap to buy, can use around 150 watts. This bulb would use 150 watts per hour, or 0.15kW if using kilo units. Assuming you have this bulb in the living room and it’s on 12 hours every day:
0.15kW x 12 hours x 30 days = 54kWh used in the month
Since we already know the energy rate:
54kWh x $0.125 per kWh = $6.75
That light bulb is costing about $7 a month and about 7% of your total $100 bill. The following table shows an example bill broken down to each item:
Notice the difference between a LED bulb and a traditional bulb! So how do I know the device wattage? Some things like bulbs, fans, microwaves have a sticker on the box that will say the watts it uses. Depending on what brand of cloth washer and dryer you have, it might be on a sticker on the side. If not, google is your friend! The same is true for all big items like the oven, HVAC unit, and refrigerator. As for the hours, they are an estimate. Unless you have a stopwatch and time your Netflix binge-watching and how long you had the fan on, just use your best guess until you reach your total bill cost. This short guide will hopefully help you next time you question your electric bill!