How Much Electricity Does Your PC Consume?
How much does it cost to run your PC? It's not a one-size-fits-all answer, but here's how to measure how much electricity your home computer consumes.
Factor 1: Where You Live
We all know we should put our computers to sleep when we're not using them, but it's easy to get lazy and leave them on all day long. How much money are you actually wasting in electricity, though, by doing that? I decided to find out.
In the US, the average cost of electricity is about 13 cents per kilowatt hour (KWh), a measurement of electricity usage over time. But electricity is more costly in certain areas than others. For example, Louisiana and Washington average less than 10 cents/KWh, while Hawaii is over 30 cents/KWh. So it helps to know what electricity costs in your city.
Factor 2: Your PC's Components
Factor 3: How You Use Your PC
Just because your PC is a beast with a 750-watt power supply doesn't mean it's going to use 750 watts all the time. Most PCs come with power-saving features that lower your energy usage when the computer is idle, or doing basic tasks like browsing the web.
So someone mining Bitcoin or folding@home
is going to use more power than someone typing up Word documents, even
if they did so on the exact same PC for the same number of hours each
day.
Measuring Your Electricity Usage
Since usage can vary so much from PC to PC
(and person to person), the best way to find out your electricity cost
is to...well, measure it yourself. You can buy a simple Kill-A-Watt meter for $15, and use it to measure just about anything in your house.
To measure your PC's usage, turn everything off, plug your PC into the Kill-A-Watt, then plug the Kill-A-Watt into the wall. (I actually recommend plugging your entire surge protector into the Kill-A-Watt—that way, you measure not just the PC's energy usage, but the monitor, speakers, and other peripherals as well).
Press the purple "KWh" button on your Kill-A-Watt meter, then turn your PC back on and use it as you normally would. Check the Kill-A-Watt once a day or so to make sure it hasn't lost power and reset to zero. I recommend waiting a week so it has a good period of usage to work with.
To measure your PC's usage, turn everything off, plug your PC into the Kill-A-Watt, then plug the Kill-A-Watt into the wall. (I actually recommend plugging your entire surge protector into the Kill-A-Watt—that way, you measure not just the PC's energy usage, but the monitor, speakers, and other peripherals as well).
Press the purple "KWh" button on your Kill-A-Watt meter, then turn your PC back on and use it as you normally would. Check the Kill-A-Watt once a day or so to make sure it hasn't lost power and reset to zero. I recommend waiting a week so it has a good period of usage to work with.
Calculating Your Electricity Cost
After a week, record the number displayed on
your Kill-A-Watt meter, making sure the purple button is pressed and
you're getting the right figure. From here, it's just a bit of simple
math: multiply that number by the cost of electricity in your area (if
your city uses tiered pricing based on time of day, just use the average
rate for your city to get a ballpark figure). The result is how much
your computer costs to run for one week.
For my tests, I left my computer on for about 12 hours each weekday—about eight of which it was in active use, since I work from home, and the other four it was left idle. Weekends saw only a few hours of use, with me letting the computer sleep most of the day.
A typical weekday's workload for me includes lots of web browsing and document writing, along with occasional gaming and other heavy workloads. At the end of the week, my Kill-A-Watt meter read 11.02 KWh of usage. Since the average cost of electricity is around 28 cents/KWh here in San Diego, my weekly cost is roughly:
11.02 KWh x $0.28/KWh = $3.08 per week
We can then estimate a yearly figure ($3.08 x 52 weeks/year) of $160.16 per year.
For my tests, I left my computer on for about 12 hours each weekday—about eight of which it was in active use, since I work from home, and the other four it was left idle. Weekends saw only a few hours of use, with me letting the computer sleep most of the day.
A typical weekday's workload for me includes lots of web browsing and document writing, along with occasional gaming and other heavy workloads. At the end of the week, my Kill-A-Watt meter read 11.02 KWh of usage. Since the average cost of electricity is around 28 cents/KWh here in San Diego, my weekly cost is roughly:
11.02 KWh x $0.28/KWh = $3.08 per week
We can then estimate a yearly figure ($3.08 x 52 weeks/year) of $160.16 per year.
What to Make of the Results
That's not as high as I expected, especially
considering my "worst-case scenario" of a power-hungry setup, expensive
city, and the fact that I use my PC all day. Given that I let my
computer idle for a few hours a day during this test, putting my
computer to sleep when I'm not using it could probably save me $30-$50 per year. That's nothing to sneeze at, but it's not exactly rent money, either.
Furthermore, most people will probably have a much lower yearly cost than me—possibly in the tens of dollars, if you only use your computer for a few hours a day or live in a cheaper city.
Of course, there are still environmental reasons to conserve electricity—especially if we all did our part—but here's the bottom line: don't stress yourself out because you accidentally left the computer on last night. It probably won't make a huge dent in your bill.
Furthermore, most people will probably have a much lower yearly cost than me—possibly in the tens of dollars, if you only use your computer for a few hours a day or live in a cheaper city.
Of course, there are still environmental reasons to conserve electricity—especially if we all did our part—but here's the bottom line: don't stress yourself out because you accidentally left the computer on last night. It probably won't make a huge dent in your bill.
Post a Comment