Most of my colleagues leave their laptops on when they go home - even over the weekends. I regard this as a colossal waste of electricity, especially when we have a public holiday coming up next Monday (May Bank Holiday in Ireland and the UK).

I've been holding my tongue about this for a while, but I do know that I'm not the only person in the office who has a problem with this. So, how can I persuade them to stop doing this?

Update A few things that came up in the comments:

  • There is an office/facility administrator, but I don't think I've ever received an email specifically about this from them. The most I've ever heard is "the entire power will be shut down this weekend for maintenance purposes".
  • Some of my colleagues occasionally need to run things overnight, which I don't have a problem with. Some of them appear to use this to work remotely, though it is possible to just bring the laptop home and access the network via VPN.
  • I don't think the computers go into hibernation - it looks like they just log out. That said, they don't take too long to boot up now that we have SSDs - maybe a minute or two.
  • 8
    I'll counter that. Forcing a cold boot each morning is a colossal waste of developer time both because of the system boot time and because of application startup (unless they can use the downtime to make them a couple coffees) and doesn't cost a single joule of energy more than hibernation does. Apr 29 '19 at 8:25
  • 4
    Do you know if they have to leave anything running on their computers over the weekend? Some hefty processes that can't be done during normal hours perhaps. Do their computers need to be on to work remotely (not always needed but some remote setups warrant it).
    – user34587
    Apr 29 '19 at 8:28
  • 4
    Is there any policy about this in your company? I've worked in several companies with clear intructions (some ask to leave it running for updates to run, some ask to turn it off "for the planet",...). Now whatever the rules, most people prefer to keep it on in order to avoid wasting time in the morning...
    – Laurent S.
    Apr 29 '19 at 8:43
  • 7
    I regard this as a colossal waste of electricity - Have you done a power usage study to determine how much power is actually being wasted... or is this just your opinion? What is the company policy?
    – joeqwerty
    Apr 29 '19 at 11:39
  • 5
    As a developer, if you impose a nightly shut down then expect to be abhorredly loathed at the office. I ALWAYS have 10-20 windows/apps open at the end of my work day and pick up right where I left off the following morning. I do not trust hibernation as I've seen them cause instability and corruptions which warrant a restart or cause a loss of work. If you dare to waste my time with shut down nonsense then fully expect to be subverted. From home I can VPN into my work PC if need be. If I decide to work remotely then I prefer not to call the office so that someone can press my power button.
    – MonkeyZeus
    Apr 29 '19 at 15:10

I regard this as a colossal waste of electricity

It's probably not as bad as you think - unless they have been specifically setup otherwise most modern laptops proactively reduce power consumption during periods of inactivity anyway. Turning off the screen, throttling the CPU/GPU, powering down any spinning rust etc. I've seen consumption figures as low as 2 watts for laptops in this state! Many will automatically enter "Sleep" mode after a certain time, and potentially even hibernation - sleep mode vastly reduces the power consumption. Most modern laptops running Win10 will use so-called "hybrid sleep" where the machine will initially enter the equivalent of the ACPI standby mode and then will hibernate if the machine remains in sleep for 3 hours or more.

So it may be the case that your colleagues are 1) oblivious to the power usage when they aren't there 2) don't care about it or 3) may actually know more than you do.

So any attempt to "stop [them] doing this" will need to address these possibilities.

  1. If they are oblivious then a reminder e-mail from the office administrator might do the trick.

  2. If they don't care you aren't going to make them care, so unless you have the necessary authority to either take punitive action against those who don't comply or reward those that do you aren't going to get anywhere.

Before we get on to point three.. looking at the language in your post: "I regard...", "I don't think the computers go into hibernation", "looks like they just log out" I get the distinct impression that you're a little light on actual facts here. Call me old fashioned but I don't think that's the best place to start from if you're looking to persuade people to change their stances or behavior so..

  1. Take some time to actually learn about what (if any) power management strategy is in place on these machines that are being "left on" - if they modern laptops running Windows 10 with the default settings then you're basically already at the optimum trade off point for most scenarios where the desire is to balance minimizing the time taken to resume producivity in the morning vs reduce power consumption.

It's point three that really brings me to my proposed solution - learn about the power management settings that are in place on these laptops and if necessary approach IT support about getting it changed.

  • 1
    Good suggestions - it looks like I have a good bit to read up on. Apr 29 '19 at 9:45
  • 1
    I agree that perhaps a power management policy could work really well in this scenario. However, I do assume the colleagues do not care about leaving their laptops on. I know nobody who leaves on their lights, tv, or computer when they go to bed without any exceptional reason. Why? It costs them money. Apr 29 '19 at 13:47
  • The answer from @James below puts this into perspective. Hardly worth the effort now that I have the figures, so I'm going to accept this. Apr 29 '19 at 15:12
  • Also, during the winter, or any time it is cold enough outside that the building's heating system must engage, basically none of the electricity being used in the laptops is wasted as it turns into heat and supplements the building's heating system with a high efficiency. Apr 29 '19 at 18:52
  • @Shufflepants - no, electric heating is very inefficient compared to ways buildings are heated. While the conversion of electrical power that makes it into the room to heat may be near 100% efficient, the conversion of heat energy to electrical power and its distribution is far, far less efficient than traditional heating sources. Apr 29 '19 at 23:23

The best way to have this happen is to show a benefit to the company.

In this answer, https://superuser.com/questions/1103136/windows-10-desktop-does-sleep-mode-use-a-lot-of-energy the power usage per year is about $15 with a high cost of power. So if the there are 10 computers that are running the potential saving is about $150 per year.

If you believe that this saving is worth your time, and administration's time to create a policy and police it, then put together a short presentation/paper and present it to management.

I would expect it to fail because the cost of the meeting would exceed an entire year's saving, and the cost of policing such a policy would would be too expensive and anger too many users that it is just not worth it.

  • Okay, that really puts it into perspective. Apr 29 '19 at 15:10

Office admin would look after these issues as it's in their job description.

You can just convey your concern and check if the administrator knows about it.

Most laptops would go to sleep if there is no activity. If there is some activity then the laptop might be left unsecured and can be misused over the weekend. I am no IT expert but I guess you can also convey your concern to IT admin as well.

  • 2
    This combined with @motosubatsu's answer would make a good all-encompassing answer. The OP's employer may not want a random employee spending (work?) time trying to figure out an energy policy for IT equipment when there are likely already people being paid to make those decisions.
    – dwizum
    Apr 29 '19 at 13:07

If you are concerned with saving electricity at the office, then the power consumed by a few laptops being left on overnight is nowhere near the amount of energy consumed by the office's air conditioning and/or heating system running while nobody is at the office.

Regardless, the best person to address your concerns with is the office administrator. It is their job to manage such matters.


In my department all of us (7) leave their PC on during the night. The reason is, that we do not want to start all the programs again, when coming to work.

EDIT: My point is, you cannot make me switch off my computer, unless you have power over me. If you want to change this, you have to talk to my supervisor.

  • 2
    Modern computers have both a suspend (to RAM) and a hibernate (to disk) option. The RAM option is really fast.
    – justinpc
    Apr 29 '19 at 9:49
  • Well, it saves me time, which is more valuable than the electricity (according to my project lead) Apr 29 '19 at 10:13
  • @QEDemonstrandum if only you paid the real cost of the energy...
    – Solar Mike
    Apr 29 '19 at 10:19
  • Switch off != log out != hibernate. It's not only about the cost in money. It's about wasting resources. Apr 29 '19 at 19:21
  • 1
    Where I work they instruct us to logout of all of our machines (I have 2) for security reasons and leave them on to perform updates which happen at night. This is at a large corporation, smaller ones would hypothetically care much less about power draw due to lack of machines.
    – Rich B
    Apr 29 '19 at 20:11

The average draw of a laptop running Windows with the screen illuminated in our environment is roughly 20W

Around 1W idle / screen sleeping.

This worst case 20W (obviously excluding recharging.) is 0.02KW/h or 0.48KWh/Day.

This is less than 5 cents a day per machine assuming it doesn't sleep.

If you are in a location that where a furnace provides heat. this is a wash, as your heating bill will drop by 5 cents.

If you are in a location where an A/C unit runs, you can add another 25% to the tab as the AC will work harder to cool the room. ~6 cents.

If you make $10/hr that is = to 17 cents a minute, or about 19 seconds of your time. If you make $20/hr ~10 seconds If you make $30/hr ~6 seconds. etc...

If you are worried about this power consumption, You may also want to worry about arriving 3 seconds late, and leaving 3 seconds early.

  • 3
    You might need to consider the cost at scale. Its not the same thing considering one pc and considering 10 or 100. Besides, OP point may not be (only) about saving money, but avoiding a waste of resource. Besides, the 3 seconds early line of thinking may be risky - maybe that's the reason why there's so much waste of resources around the world. Apr 29 '19 at 19:25
  • 1
    I'm also surprised you didnt mention hardware longevity. Hard drives dont last forever, especially SSD's. The average can be around ~3000 write cycles. While your computer is turned on this flash memory is being accessed, albeit at a much lower rate, but still active. Not to mention the CPU, RAM, motherboard, GPU, monitor, fan... These components all will wear faster, so its just simply their power cost that OP is concerned with.
    – Rich B
    Apr 29 '19 at 19:59
  • 1
    @RichB - It is extremely hard on a system to be turned off every single day then turned on. I have machines I left on 24/7 for years without a single failure. A CPU was designed to be left on, there are machines that exist, that remained turned on for years without a reboot.
    – Donald
    Apr 29 '19 at 21:00

Some points: My computer is none of your business. Touch it at your own peril; it would make me very angry, and you don’t want that. If my computer is turned on and running then it is turned on and running for a good reason. If I waste five minutes of my time turning on my computer that costs the company ten times more than you can ever save. Same if I waste five minutes of my life discussing this with you. I’d make a mental note that you are a busybody and jobsworth.

Summary: don’t do it.

  • 11
    As threatening, I'm sure, being considered a 'busybody' by you is I believe the OP is more concerned for the environment, not your time. You are replaceable, the environment isn't. Apr 29 '19 at 9:10
  • 1
    +1 The power use has to be insignificant compared to lost time and I can see how making an issue of this could annoy your colleagues. This does not deserve to be down-voted environmental concerns notwithstanding.
    – Old Nick
    Apr 29 '19 at 15:13
  • 2
    @LioElbammalf I'm not replacable. I would be missed. I don't annoy people to save pennies. "The environment isnt"... The power that my computer uses overnight isn't missed.
    – gnasher729
    Apr 29 '19 at 19:19
  • 1
    @gnasher729 It isn't personal - I'm sure you do a perfectly acceptable job - but someone concerned for the environment isn't interested in saving pennies or your time, they're interested in reducing the carbon footprint of the company. Whether putting computers to sleep is a viable way to do this or not is the debate that should be had, not a rant about how important you think your time is. Apr 30 '19 at 7:46

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