University of Southampton


How do I save energy whilst at the University?

The obvious way to avoid wasting energy and to save money is to switch equipment off when it isn't in use.

The Unversity practices the IT Switch Off and Power Management Policy

How much energy do PCs use?

The energy used depends on all kinds of factors such as type of processor, amount of RAM, number and size of screens, and the applications used. Heavy-duty number crunching makes the processor and fans work much harder than word processing and web browsing!

However, a modern office PC with one 19" LCD screen takes around 80W for typical office tasks. If left on all day, every day, it would consume 700 kWh per year, equivalent to 382 Kg of CO2 and costing £84 (at 12p/kWh).
If you have a second LCD screen, it would add another 350 kWh, 191 Kg of CO2 and cost a further £46.

What power management options does iSolutions use?

Windows 10 office PCs managed by iSolutions use a power management plan designed to maximise energy savings while minimising any impact on your work:

  • After 10 minutes your screen powers down (40% saving)
  • After 30 minutes your PC will enter sleep mode (95% saving)

It only takes a few seconds to wake up from this state.
Assuming the screen powers down for a total of 2 hours during the working day (say 9.00 - 5.30) but only enters sleep at 6.00pm, the energy consumed each year will be 192 kWh (a 73% saving over the 'always on' scenario). This also saves 277 kg CO2 and £61 - so multiply this by the thousands of PCs in the University and the savings are really significant

Windows 10: saving even more energy

You can make even greater savings by manually selecting Sleep from your PC's Start menu at the end of your working day. In the example above, if the PC enters hibernation at 5.30 rather than 6.00, it saves an extra 75.7 kWh, 3.1 kg CO2 and £0.69 annually. It may not seem much, but that extra 0.8% saving is still significant given the University's target of a 20% reduction in energy consumption.
If you are able to switch off your PC at the wall so that it uses no electricity out of working hours the savings are much greater: 31.9 kWh, 17.4 kg CO2 and £3.83 annually. That is a 4.6% saving over the automatic power plan. In some offices, the power switches are inaccessible and this extra saving is not possible.

Power modes on a PC:

Sleep mode - most computer functions are powered down apart from the RAM memory. It only takes a few seconds to wake up from this state.

Hibernation mode - The contents of the RAM memory are written to the computer's hard disk, then the computer powers down. It takes about a minute to wake up from this state.

Hybrid sleep - is a cross between sleep and hibernation, usually used by laptops. The RAM is copied to the hard drive in case the battery runs out and the computer shuts down completely, but otherwise it acts as if it were in sleep mode.

Why should I adopt energy-saving practices?

The University has set an ambitious target to reduce carbon emissions from energy use by 20% by 2020 (from a 2005/06 baseline), and the IT Switch Off and Power Management Policy makes an important contribution to that objective.

In addition, the University recognises that everyone will have their own motivation for taking sustainable actions, be it reducing our global footprint, improving our local environment, or the substantial financial saving that comes from reducing our energy usage, which can be reinvested in the University. We also have a legal obligation to reduce our carbon emissions, and we know that our current and future students will increasingly call for us to do more.

 When should I switch off IT equipment?

Whenever it is not in use. By putting your PC into sleep mode when you leave your desk to go to a meeting or to lunch can shave around 17% off your annual power usage. Switching it off at the wall over the weekend and when you are on leave saves even more. Personal printers and phone chargers should be switched off when not actually in use, and the same applies to the screens of computers that are running lab experiments.

What if I need to access my files when I am away from the University?

You do not need to leave your PC on unless the files are stored on the hard drive of the PC. You can access all the documents in your My Documents and J drive filestore from outside the University by using a VPN Connection. Once you have set up your home PC to use VPN (Virtual Private Network) it is used to establish a secure link to the University network, so you can access all the services you use at work.

If you really need to access your PC, perhaps because it has specialised software installed, then please make sure that the screen is switched off when not in use i.e. overnight, at weekends and when you are away from the University.

Was this article helpful?

If you have any further comments, please put them below.

Please note that feedback is anonymous - if you require a reply or assistance, please raise a ticket via ServiceLine.

Thank you for your feedback, it is much appreciated.

Tweet This Article

Back to List

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.