photo of person typing on computer keyboard

Computer & ICT use

Computer technology helps reduce (video conferencing, better efficiency, knowledge accessibility, climate modelling), but also increase (prolonged use and dependency with energy consumption, social availability) elements of sustainability.

Computer use and the systems that support our ICT use a lot of energy. Some estimates suggest about 10% of all electricity generated goes to power our smartphones, tablets, laptops, desktops, data centres and all the systems that support them. 10% equates to the energy production of Japan and Germany combined (and these are large and energy hungry countries).

It is therefore important to find ways to reduce the consumption of these devices. The following gives advice and information to help us understand the challenge and provide some useful guidance to help bring down this data-based impact.

Quick & Simple advice: power down, switch off, unplug.

Computers & laptops

There are many steps you can take to reduce your computer’s impact on the environment.

  • Set your computer to automatic sleep mode after 5-15 minutes of inactivity.
  • Plug all your system components into a single power strip and turn it off when you shut down.
  • Always turn off your computer and peripheral components when not in use.
  • Since the display consumes most of the power, set the monitor brightness to the lowest setting you can see without straining your eyes.
  • Keep peripherals (such as speakers, printers and scanners) off when not in use.
  • Use a laptop when possible, because laptops consume less power than desktops.
  • When looking for laptop computer deals, look for Energy Star approved models.
  • Close applications you’re not using.
  • Where possible avoid sending large files (and particularly to large email lists especially if it is not needed by many of them). Embed links instead if appropriate.
  • If you are using a university desktop computer click the green square in the bar at the bottom bar on the right. This gives you an idea as to how much you are using your computer, and how much it is in sleep mode and helps you see how much your computer may be inactive. This can help you better manage your computer use.
  • Some companies are using efficient data centres or powering them with renewable energy (such as Apple). Support such organisations that act responsibly on the planet’s  (and your) behalf.


Some calculations suggest a heavily used smartphone can use the same energy as a medium sized refrigerator. We may not think that the energy used to send and receive data, the draw from wifi-systems, servers and other parts of the infrastructure all have an impact – and with more use comes a larger carbon footprint.

The University of Greenwich ICT & Sustainability Initiatives

Greenwich’s ILS department is a key member of the Carbon Management Board as it has a significant carbon footprint and has undertaken the following sustainable initiatives:

  • Encouraging energy saving behaviour by users of non ILS managed desktop computers.
  • Monitoring energy use by desktop PCs, servers and network infrastructure.
  • Including power consumption as a key factor in equipment purchasing decisions.
  • Moving from myriad office printers to a Managed Print Service. (MFDs)
  • Replacing many physical servers with virtualised servers.
  • Optimising the energy used by our current server room.
  • Ensuring that the new planned data centre is as efficient as possible.
  • Re-using unwanted IT equipment and minimising WEEE waste.
  • Minimising packing waste from deliveries of new IT equipment.


For further information about improving the sustainability of ICT then download this useful toolkit.

University of Greenwich Sustainability Blog