ICT Sustainability

Assessment and Strategies for a Low Carbon Future

An Online Graduate Course & Book by Tom Worthington MEd, FACS CP

Skip to content

Methods and tools can be used in the planning, development, operation, management and maintenance of systems for Energy saving and to plan Materials Use.

Analysis of ICT in energy use

The Climate Group, provide three appendices for their SMART 2020: Enabling the low carbon economy in the information age (2008):

  1. Scope, process and methodology,
  2. The Direct Impact Assumptions,
  3. The Enabling Effect Assumptions.

These technique can be used both for estimating the carbon footprint of ICT and how it may be used to reduce emissions in other sectors by using ICT.

The analysis measures emissions CO2e, assuming, the ICT sector covered:

The study excluded consumer electronics in the home: TVs, video, gaming, audio devices and media players. Specialised electronic devices, such as medical equipment was also excluded. Different assumptions would need to be made for organisations in specific industry sectors. As an example, a games software developer could not exclude computer games and a hospital not exclude medical devices.

Staged study

The Climate Group carried out three phases of their study:

  1. Quantify the global impact of ICT: Models were developed for the direct footprint and the indirect (enabling) opportunities.
  2. In-depth case studies: Emissions reduction opportunities using ICT were developed.
  3. Assessment of imperatives for stakeholders: Workshops were conducted to investigate opportunities and barriers for: technology providers, technology users, investors and regulators.

Direct ICT impact (footprint) methodology

The Climate Group used published estimates of global emissions and penetration rates of ICT devices and infrastructure. Estimates of population growth were then used to calculate future emissions in 2020. Data was from public studies; academic and industry literature; the team experts, consumer surveys and interviews with external experts.

The analysis attempted a "cradle-to-grave" estimate of carbon emissions: manufacture, transport, use and disposal of equipment.

Embodied carbon: CO2e in manufacturing of ICT components was calculated from public and company data. Embodied energy in end-of-life treatment: disposal, landfill and recycling, was included where data was available.

Energy consumption of the components based on publicly available company data. An emissions factor was used to calculate the carbon emissions from energy consumption. The emissions from electricity generation vary depending on the technology used. The Climate Group divided the world into regions and used a different emissions factor for each region. Transmission losses in the electricity grid were similarly estimated.

Market growth and penetration of devices to 2020 was based on industry reports and internal analysis. Growth in use of ICT and general industrial growth is more significant in developing areas of the world.

Enabling impact methodology

The Climate Group used a cost curve to identify emissions abatement solutions ranked by cost. The study concentrated on areas where emissions are significant: power; manufacturing; industry; transport; residential and commercial buildings; forestry; agriculture; and waste disposal. ICT applications were then assessed for use in reducing in emissions abatement on the cost curve. Four uses for ICT were then selected for detailed analysis.

Direct impact assumptions

The Climate Group were undertaking a high level global analysis and therefore used some very general assumptions in their analysis. As an example: 20% of desktops are workstations, Workstations consume 2.5 times desktop in all modes, Commercial usage of a computer is 14 hours/day versus consumer usage of three hours/day, Three types of servers: 200, 500, 6000W/unit. These assumptions are listed in Appendix 3: "The Enabling Effect Assumptions" of the report (The Climate Group, 2008). An analysis for an organisation may use locally developed estimates or actual measures, but may also use these same assumptions, in order to enable a direct comparison.

Enabling effect assumptions

The Climate Group made assumptions as to the effect ICT could have on other industry areas. As an example, it was assumed that on-line media would replace DVDs and CDs. This assumed seven billion DVDs and 10 billion CDs globally were sold per year, with 1 Kg CO2e per CD/DVD and all this would be replaced with network delivery of content by 2020. Similarly electronic documents were assumed to reduce paper use by 25%. Organisation based studies should be able to use better estimates or local measures of disk and paper use.

Estimating Power Management Savings for Computers

The Foundation for IT Sustainability (FFITS) provide instructions to Activate power management on Windows 7 (FFITS, 2011). The Consortium for School Networking provide an Energy Usage Calculator (CoSN, 2010).

FFITS provide instructions to configure power management for operating systems including Apple Mac, Microsoft Windows XP and Vista. They recommend setting computers to enter system standby or hibernate after 15 to 30 minutes of inactivity and set monitors to enter sleep mode after 5 to 20 minutes of inactivity. On laptops, these need to be activated in the AC power profile, as well as battery power) profile.

The CoSN Energy Usage Calculator (2010) prompts for the number of items of computer equipment, power use for each and the price of electricity, Hours in Workday and Days in Work week. Defaults are provided for the Active Power and Sleep Power (in watts) used by monitors and PCs. Estimates of the proportion of units power managed, Units Turned Off After Work are used and Tons CO2 are calculated.

It should be noted that the CoSN Energy Usage Calculator (2010) uses US defaults for the conversion factor for estimating carbon dioxide emissions from electricity used. The conversion factor varies from state to state in Australia and country to country around the world, depending on how electricity is generated. As Australia uses predominately coal fired power, an Australian calculator will give a higher estimate than a US calculator, where less coal is used.

Energy Consumption and Carbon Footprint of ICT Usage in Australia in 2010

The estimate of Energy Consumption and Carbon Footprint of ICT Usage in Australia (Philipson, 2010), divided ICT use into two categories: Households and Enterprises. The number of household users was derived from national statistics. The number and size of enterprises was obtained from national statistics, with industry categories used to estimate the likely intensity of ICT use.

Now Read

  1. Scope, process and methodology (Appendix 1), The Direct Impact Assumptions (Appendix 2), and The Enabling Effect Assumptions (Appendix 3) of SMART 2020: Enabling the low carbon economy in the information age, by The Climate Group (2008)
  2. Activate power management on Windows 7 (FFITS, 2011)
  3. Energy Usage Calculator (CoSN, 2010)
  4. Methodology from Energy Consumption and Carbon Footprint of ICT Usage in Australia (Philipson, 2010).


  1. Use an energy usage calculator: Use an energy usage calculator to estimate the power use and greenhouse gas emissions of your organisation's computers. List the assumptions you made.
  2. Assumptions about energy use: The Climate Group made many assumptions about energy use by computers in their SMART 2020 report. Identify one of the "The Direct Impact Assumptions" (Appendix 2) which does not apply in your organisation, region or industry sector. What figures would you use and why?

Next: Sustainability Strategy.

About the book: ICT Sustainability: Assessment and Strategies for a Low Carbon Future

Edition Notice

ICT Sustainability is about how to assess, and reduce, the carbon footprint and materials used with computers and telecommunications. These are the notes for an award winning graduate course on strategies for reducing the environmental impact of computers and how to use the Internet to make business more energy efficient.

Copyright © Tom Worthington, 2017

Second edition.

ISBN: 978-1-326-96794-9. (Hardcover)
ISBN: 978-1-326-95850-3. (Paperback)
ISBN: 978-1-326-95849-7. (ePub eBook)
ISBN: 978-1-326-96791-8. (PDF eBook)

Cover shows Power on-off symbol: line within a circle (IEC 60417-5010).

These notes have been used for the courses:

  1. Green Technology Strategies: offered in the Computer Professional Education Program, Australian Computer Society (first run as "Green ICT Strategies" in February 2009),
  2. ICT Sustainability (COMP7310), in the Graduate Studies Select program, Australian National University (first run July 2009), and
  3. Green ICT Strategies (COMP 635), Athabasca University (Canada). Adapted for North America by Brian Stewart.

Course materials available free on-line, under at Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0) license at http://www.tomw.net.au/ict_sustainability/