should you shut down your computer?

Shutting off your computer every night has downsides. If you just put your computer to sleep, everything is right where you left it in the morning. But if you shut down, you need to wait for your computer to boot up and then re-open all of your applications and documents. It’s annoying.

I wanted to get an idea of just how little power so I ran a few simple tests. First, I charged my laptop around 6PM after an afternoon of using it outside. In that time, it was just about fully charged, after which I unplugged it and closed the lid. The charge in my laptop barely went down—only by one percent—and this is on a nearly six year old laptop with a battery that doesn’t hold a charge like it used to. 

I wanted a slightly more precise number, though, so I used a Kill A Watt to measure how much power my laptop uses when asleep. Leaving it plugged in and suspended from 4PM until 7AM the following morning—15 hours—used up 0.02 kWh of energy. That’s not a lot. Here in Portland, Oregon the price per kWh for residential use is 19.45¢, meaning leaving my laptop plugged in overnight cost me a little over one third of a penny. Over the course of an entire year this adds up to $1.42. 

Now, this isn’t to say that you should never shut down. I shut down my laptop if I’m leaving town without it for more than a week. At that point the amount of energy the computer will use, compared to the annoyance of having to start it up again, tips back into being worthwhile for me. Plus, sometimes a sleeping laptop will run out of batteries when left alone that long, which is just plain annoying.

And there’s another reason to shut down, or at least restart, your computer regularly: it can sometimes solve annoying computer problems. The main reason for this is software bugs—over time such issues can fill your device’s memory and generally just cause your computer to become unstable.

-- Justin Pot, Popular Science