ICT Sustainability

Assessment and Strategies for a Low Carbon Future

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

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Quality management can be used to ensure that sustainability is considered as part of performance in the design, development and implementation of ICT products and services. Quality Improvement looks to change a process to improve the reliability of achieving an outcome. Quality Control is carried out to maintain reliability of achieving an outcome. Quality Assurance is used to provide enough confidence that the set requirements for quality are met.

Quality is an abstract concept. To make it more concrete, the issue of measuring and improving the energy efficiency of desktop computers, servers and data centres equipment is discussed. The most widely recognised standards for ICT energy efficiency are the US EPA's Energy Star Program (2010).

The US government mandated the implementation of Energy Star V4 program in July 2007 under the Federal Energy Management Program (FEMP). Energy Star Version 5.0 Program Requirements for Computers (2008), required that a small desktop computer use no more than 148 kWh of electricity per year. Energy Star specifications were also developed for Computer Servers (2011a).

Quality Standards

The International Standards Organisation (ISO) Quality Management System (QMS) set of standards was first released in the late 1980s. These give guidelines for performance improvement and provides a measurement framework for improved quality management. The most commonly cited quality standard is "Guidelines for performance improvement" (ISO 9004:2000).

US Energy Star Program

Energy Star: Computer Key Product Criteria, Version 5 (2008) covers Desktop PCs, Notebooks and Thin Clients. Some issues remain with the specification:


Energy star defines different power and efficiency limits to different categories of computers. Also some components of computers are separately rated. Therefore the definition of types of computers and components are important to the specification:


Computer Types

Operational Modes

The specification sets different power consumption levels for different modes of operation of the types of computers. Earlier versions of the specification only measured power consumption when the computers were not carrying out useful work. Measures when the computer in use are introduced with the new version and a Typical Energy Consumption (TEC) estimating the typical electricity consumed by a product in normal operation over a year.

Internal power supplies for computers are required to be at least 85% efficient at 50% of rated output and 82% efficient at 20% of rated output. It should be noted as a result that, as with data centre provisioning, purchasing computers with excess electrical capacity will reduce efficiency.

The allowed total energy consumption for a year for Desktop computers ranges from 148 to 234 kWh, depending on the category and for Notebooks from 40 to 88.5 kWh. There are adjustments to these for memory, graphics and storage. It should be noted that therefore specifying a higher performance computer than needed could result in higher energy use while still meeting the Energy Star requirements.

Energy Star Program for Computer Servers

The ENERGY STAR Computer Servers Version 2 (2011) defines a Computer Server as:

"A computer that provides services and manages networked resources for client devices, e.g., desktop computers, notebook computers, thin clients, wireless devices, PDAs, IP158 telephones, other Computer Servers and other networked devices. ...".

As with the specification for desktop equipment, different Computer Server Types are defined, including Blade Servers and High Availability Servers. Also Other Data Center Equipment, including Network Equipment and Storage Equipment are defined.

As with the desktop specification an emphasis is placed on the efficiency of Computer Server Power Supplies. But only one Operational State is defined for servers: Idle. Unlike desktop equipment which may be left on doing no useful work and so may switch to a low power state, it is generally assumed that servers will be constantly busy.

Now Read

  1. US Department of Energy's History of ENERGY STAR (2010) and Energy Star: Computer Key Product Criteria, Version 5 (2008),
  2. International Standards Organisation Quality management systems - Guidelines for performance improvements AS/NZS ISO 9004:2000 (pages 1 to 12).


  1. Describe the Quality Management process of your organisation: Describe the Quality Management process of your organisation, or or an organisation you are familiar with. Is the organisation formally certified under ISO 9001, or some other system? How might such a process be used for furthering Green ICT aims?

  2. Matching computer power to the user's needs: Version 5.0 of the ENERGY STAR Specification for Computers sets different power limits for different types of single user computers: Desktop, Integrated Desktop Computer, Thin Client, Notebook, Workstation. Outline a policy for your organisation proposing to lower energy use and costs, by matching the computer to the user's needs. What would be the energy and cost savings for your organisation over three years?

Next: Appendixes.

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, 2018

Third edition.

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

Latest version of 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/

Previous edition, 2017:

ISBN: 9781326967949 (Hardback)
ISBN: 9781326958503 (Paperback)
ISBN: 9781326967918 (PDF)
ISBN: 9781326958497 (ePub eBook via Lulu and Apple)
ASIN: B005SOEQZI (Kindle eBook)

Editions of these notes have been used for the courses:

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