Maybe. It depends.
The issue isn't as simple as you might think; there's no single answer to this perennial question.
My answer, naturally, is "It depends."
There are two issues at play here: the power used by a computer left running 24 hours a day and the stress on hardware components being repeatedly turned off and on.
Become a Patron of Ask Leo! and go ad-free!
Turn computers off at night?
Turning your computer off at night can save power, but standby mode uses almost as little energy. Turning the machine off and on over time repeatedly could stress some components, leading to earlier replacement. However, modern parts are built for this. With no simple answer, decide based on your usage. In particular, prioritize whatever enables automated backups; they're important.
Power consumption
Power consumption is the easier question.
In most cases, standby is almost as good as turning your computer off completely. The computer uses a little power to keep itself ready for use, but components using the majority of the power, like spinning hard drives or display devices, are turned off.
Of course, turning the computer off completely prevents power from being consumed at all.1
Before you decide that standby or power-off is what you want to do to save electricity, it's important to realize that your computer may already be taking steps on its own to minimize power usage when you're not using it. Many individual components go into the equivalent of standby on their own if they're not used for some period of time. Hard drives may turn off after some period of inactivity. Screensavers eventually turn video displays off. Even a wireless mouse or keyboard may assume a low-power state when they haven't been used for a while.
Depending on your computer, it's quite possible that simply walking away reduces the amount of power being used.
Stress (the computer's, not yours)
There is an argument that says leaving a component on continuously is less stressful than turning it on and off repeatedly. While you may save power while the device is off, the stress of heating up and cooling down over and over when starting and stopping can contribute to earlier failure and required replacement.
The argument is that the cost (in terms of purchase price and the environmental impact of replacing a broken component) is so high that in the long run, it would be more cost-effective to simply leave it on all the time.
The counterargument is that most components are built with this in mind. As I mentioned, many components turn themselves off after some period of inactivity, whether you tell them to or not. The devices are built to power cycle fairly frequently.
And in almost all cases, devices already last longer than we need them. Devices are most commonly replaced not because they fail, but because newer and more powerful devices are purchased.
What I do
As you can see, there's no simple answer. There are arguments for both approaches.
My approach is to ignore all of the arguments above as they more or less cancel each other out. Instead, I make the decision based on how I use my computers.
It's no surprise that I am a heavy computer user, and for me, the answer is to leave almost all of my equipment running 24 hours a day. Not only does that keep everything ready and running for my use, but it also allows automated processes like updates and backups to happen in the wee hours of the night when I'm asleep.
Do this
My expectation is that an average user who uses their computer a few hours a day would most likely turn it off or put it into standby when it's not going to be used for a few hours or more. That's simply to minimize power use. It's also not a big deal if you don't.
If you use it longer, perhaps you leave it on all the time. Again, no big deal.
If there's anything I might consider a tipping point in the decision, it's backups. If leaving your computer on all the time allows you to automate the process and take backups where you otherwise would not or would forget, then in my opinion, it's worth it.
Backups trump everything.
Something else that helps? Subscribe to Confident Computing! Less frustration and more confidence, solutions, answers, and tips in your inbox every week.
Podcast audio
Related Video
Footnotes & References
1: Surprisingly, not quite true on some machines. Even when you turn the power completely off, there are often components that remain powered to some degree. Only pulling the power plug prevents this tiny trickle of electricity from being used if it is on your specific machine.
“And in almost all cases, devices already last longer than we need them. Devices are most commonly replaced not because they fail, but because newer and more powerful devices are purchased.”
I’ve had several computers over the years, desktops and laptops. I’ve never had a computer die of old age. I’ve only taken them out of use when the OS was no longer receiving updates and the machine was incapable of getting a supported version of the OS. Even then, I’ve converted some to Linux and used them a couple more years.
I do the same. Or I dramatically reduce my expectations.
– My 10 year old Mac Pro is now a server in my basement. Works great.
– I have an even older HP that’s running Ubuntu Linux with 11(!) external drives connected acting as a psuedo-NAS
But I also have older machines that are sitting around doing nothing, waiting for the digital knacker.
Does this advice and suggestions apply to laptops also?
Yes.
Doesn’t keeping a laptop plugged in all the time shorten battery life, or does the computer manage the charging?
I’ve been told that modern laptops and chargers now handle this properly.
I assumed that, but I wasn’t sure. I usually charge my phone all night as it’s the easiest way to be sure I get it fully charged.
Is there an article about how to share external disks attached to a Linux machine with other Windows PC:s that a home user can configure?
I don’t have such an article. I’ve done it, and it’s not really trivial. The keyword to look for is “samba”, the windows file sharing software for Linux. Configuring Samba can be a little tricky, especially if you want controlled access.
Dude! WhT did you enter as the prompt for DALL-E 3 to produce that great image!? (And — just curious — why DALL-E 3 rather than DALL-E 4?)
Sadly I don’t recall the exact words, and I’m not finding what I entered in MidJourney. I believe MidJourney only has 3 right now.
I didn’t find anything on how to proceed to leave it on!
Should I use the Sleep option, Hibernate, or let the computer “decides” after x hours of inactivity?
Thanks for clarifying!
There is a setting for all of those under Power Options. Set them all to never.
The problem still exist, in that when a PC heats up things expand and as it cools things contract. While components, especially capacitors are better designed to handle that, motherboards & adapters and all their solder points are still a bit subject to cold-solder points, where things crack & loosen from their connections.
So still say if used everyday (other than storms coming in) leave them on.
As far as batteries, if you start using your notebook PC on battery power, still best to use on battery power until runs down, before charging. For best battery life.
Like phones, to calibrate, run battery all the way out, then recharge with unit off until completely charged and then another hour, at least, before powering on.
That is less true than in times past. Many chargers have circuitry that regulates the charge and automatically discharge when the battery is full.
@Mark: I’ve look into this, but can’t find the Settings you refer to. There are many settings: Balanced, High performance, etc.
The only thing I found was to have my computer “Sleep” during the night. Yet, I’ve read somewhere that this is not a good solution since the computer updates will not run smoothly.
I’m still in fuzzy about this… don’t know what to do!
I generally put my computers to sleep to save a little electricity. Previously, that required a restart a couple of times a week to keep it running well. Now Windows is so stable, the only time I need to reboot is for updates.
On my Linux machines, I sometimes (two or three times a week) find it getting very sluggish, and a reboot fixes it. It’s got to the point, I just turn it off at night. So much for Linux being more stable than Windows.
I have always wanted to leave my computers turned on but have not done so. I have wondered whether my machine, when they are on line to the internet, are vulnerable to any bot for malware or could be used for other malicious actions such as denial of service attacks.
Just got around to watching this video. I have been running my own computer business for 35 years and agree with most of your points. One thing I stress to all my clients is that if you do leave your computer running, you need to restart it on a regular basis, say once a week. Windows gets worse the longer it runs and the only way to refresh it is to restart it. This point should have been made in your video.