Save £23,000 or Save the Earth…take your pick

PC Pro have been doing some research on the ways that Windows Vista can save power.....come power?


It appears that computers are left on all the time with nobody using them (hmm, let me think about the IT Suite, or some of those odd computers in the back of teaching rooms). So, if you managed them better, you'd start saving power - and either save money or the planet, depending on your views (of course, you do both).

And how does it do this? Well, I'm glad you asked...

Windows Vista has a "sleep" mode, which is automatically activated if you don't use your PC for an hour, or you activate it yourself by hitting your power switch. What that does is move your PC into an ultra-low power state, where only the RAM is powered, everything else is closed down (processor, disks, screen etc). Which means that when you want to switch it back on, it comes back in two seconds (yes, really).

Based on a typical user using that better will save £23 to £46 a PC a year, just by switching the operating system. Now, in a typical FE college in England, which according to the Becta survey has 1,000 PCs, that is at least £23,000 a year in electricity, or over 750 tonnes of carbon emissions. Just by changing some sofware.

Want the evidence? Here's the PC Pro Labs Survey

  • Factoid 1: Your PC uses varying amounts of power depending on what it is doing - the power supply rating is the maximum it can produce. So a 350 watt PC doesn't use 350 watts all the time - if ever. 3D rendering uses twice as much power as using Word. Running the screensaver uses more power than doing nothing! A 250 watt desktop used around twice the power of a 65 watt laptop.
  • Factoid 2: I've been using Sleep mode on my laptop for months. I put it in Sleep whenever I've finished taking notes in a meeting, and then bring it back on whenever I want to make more notes, because it is so quick to restart. I was doing it to save battery power (giving me a whole day's use from a single charge), but now I know I've been saving money/the earth too
Comments (3)

  1. Adrian Mannall says:

    Not sure where you got the £69,000 figure from – well I do – but it’s a bit of wrong maths …

    If you can save between £23 and £46 per PC and you have the average of 1,000 PCs then the minimum you can save would be £23,000 and the maximum would be £46,000.  You can’t save more by adding the minimum and maximum together – although that would be nice!

    I hope this is just a typographical error rather than something calculated – or was it done using iWork Numbers? ;o)

  2. Ray Fleming says:

    Hi Adrian,

    I can’t believe I made such a howler – and that I haven’t spotted it since April when I posted it.

    My calculator finger must have been having a bad day. Anway, all corrected now (to a more reasonable £23,000). Which is still a big number?

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