Last updated on March 10th, 2024 at 03:13 pm

My recent experiment with how much energy it takes to run a microwave really had me thinking…if the label was a little off on the microwave, could the labels on other appliances be wrong as well?

No sooner than I turn around in my house from the microwave to find the coffee maker sitting right there. Of course! Coffee. I love coffee, like most other people. I run my coffee maker everyday because its far cheaper to make coffee at home than go out and buy a cup of coffee on my way out.

How much cheaper? Well, I figured it out. Based on 25 days a month (that’s 25 cups of coffee a month):

• At $1.65 a cup, it would cost $41.25 per month to buy from the coffee/donut shop (Tim Horton’s)
• If I made coffee at home, I could make 1/2 a pot of coffee at a cost of about $22 per month. *

But, the one thing that’s missing from this equation is the energy cost associated with making the coffee at home. Obviously, its not going to cost $19 to bring it on par with buying coffee already pre-packaged in a nice to-go container. But how much extra would it be?

Well, I set out to find out.

Measuring energy consumption of the electric coffeemaker

I have a Melitta grinder/brewer at home. Most of the time, I don’t use the grinder, just the brewer. I usually just buy the grounds because its easier on me. And its less of a cleanup. I connected an energy meter to the coffee maker and fired it up.

• On standby (unit just turned on) the unit uses about 3w of power.
• When the brew cycle starts, the consumption shoots up to 1003w
• As the cycle continues, the consumption levels at about 985w
• After the brewing is complete, consumption drops to 3w again.

Remarkably, it would appear that the warmer plate uses so little energy that the meter didn’t even notice it!

Compare these figures with the label of 1025w of power consumption. It’s obvious the unit, on the whole uses far less energy than the label would lead you to believe. (I’ll be writing more about this shortly).

Calculating the energy cost

To make 1/2 pot of coffee, it takes about 5 minutes. If I make coffee 25 times a month using this method, it takes a total of 125 minutes. That’s a little over two hours (for simplicity’s sake, we’ll call it an even 2 hours.)

Since the energy consumption levels at about 985w (after the initial short spike) we’ll use that figure rather than the higher one as it makes the most sense.

I pay about $0.10 per kwh (after taxes and other charges are added in). This means:

((985×2)/1000)*0.10 = $0.197, or about 20 cents per month.

If I left the coffee maker on all month (@ 3w continuous power draw):

((3×718)/1000)*0.10=$0.2154, or about 21 cents per month.

(I took away the two hours of usage, as assumed 30 days in a month, giving me 718 non-use hours in a month.)

Add the 20 cents to the coffee cost at home of about $22, and we see how incredibly efficient it is to make coffee at home, even with a high powered appliance that is used every day.