Green IT Factsheet

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Information Technology (IT) offers many benefits including increased productivity, access to information, and convenience. However, the production, use, and disposal of computers require large amounts of energy and resources. Green IT enhances the sustainability of computing through manufacturing lower impact materials and products, reduced energy consumption of data centers and computers, and better recycling and end of life management.

Patterns of Use

  • Data centers in the U.S. consumed 91 billion kWh of electricity in 2013—2.4% of total electricity consumption—at a cost of $13 billion.1,2
  • The peak load on power plants associated with servers and data centers was about 7 gigawatts (GW) in 2007. Updated technologies can reduce server energy use by 25% or more, while using best management practices with existing equipment can reduce energy use by around 20%.3
  • Computers and office equipment accounted for 24% of the total electricity consumption (253 billion kWh) of office buildings in 2012.4
  • In 2011, 76% of households in the U.S. had a computer or a tablet, compared to 51% in 2000.5 Globally, 1.4 billion smartphones, which have capabilities similar to a computer, were sold globally in 2015, up from 174 million in 2009.6,7
  • From 2005 to 2009, the proportion of primary household computers that were laptops rose from 31% to 44%.8,9 More than 14% of primary household computers were used 10 hours or more a day in 2009.9

Energy and Environmental Impact

  • Approximately 103.9 billion lbs CO2e are released annually due to electricity used by U.S. servers & data centers.1,11
  • Electricity consumption of computers varies greatly with age, hardware, and other factors. An average multimedia desktop computer uses 48W when idle and 2.3W in sleep mode (285kWh annually). Laptops use significantly less energy - about 15W when idle and 1.2W in sleep mode (89kWh annually).12
  • A 17” liquid crystal display cold cathode fluorescent lamp (LCD-CCFL) monitor uses 16W while on, 1W in standby, and 1W when off. A 17” light emitting diode (LED) LCD monitor uses about 13W while on, 0.4W in standby, and about 0.3W when off.13
  • For every kilowatt hour used by office equipment, an additional 0.2-0.5 kWh load is placed on the air conditioning unit.14
  • The annual life cycle burden of a computer is 5,600 MJ. Only 34% of life cycle energy consumption occurs in the use phase; extending the lifetime could mitigate the energy burden of the production and disposal phases.15

Electricity Use by U.S. Data Centers, by End Use1,2

Figure_1_Electricity Use by U.S. Data Centers, by End Use

Power Used by Office Equipment10

Power Used by Office Equipment

Electronic Waste

  • In 2014, approximately 41.8 million metric tons of e-waste was generated worldwide.17
  • U.S. federal hazardous waste regulations do not deter exporting potentially hazardous e-waste, which is often handled and disposed of unsafely, threatening humans and the environment.18 One study estimated that 5-30% of e-waste collected for recycling in the U.S. is exported to developing countries, although a study by the U.S. International Trade Commission found that 17% of used electronic products were exported in 2011.19,20
  • In 2010, the U.S. disposed of 51.9 million computers and 152 million mobile devices (phones, PDAs, pagers). About 40% of computers and 11% of mobile devices are recycled.21

Composition of a Desktop Computer16

Composition of a Desktop Computer

Paper Industry

  • Global paper use increased 4% from 2000-2014 but has decreased 6% since 2011.22,23 Annual consumption of printing and writing paper is projected to increase from 109 million metric tons in 2006 to 274 million metric tons in 2060.24 The U.S. accounts for approximately 18% of printing and writing paper consumption.22
  • Depending on the production process, one ton of paper can take between 12 and 24 trees to produce.25
  • The average annual greenhouse gas emissions of the U.S. pulp and paper manufacturing industry are 176 million metric tons CO2e, approximately equivalent to the annual emissions of 51 coal-fired power plants.26,27
  • One study comparing paper and digital journal articles found that life cycle energy consumption varied greatly depending on the number of times an article was read, the reader’s driving distance, and whether copies were printed. Generally, the study found that the digital option saves energy when an article is read only a few times, and paper saves energy when an article is read many times.28

Life Cycle Impact of One Ton Uncoated Freesheet Paper29

Life Cycle Impact of One Ton Uncoated Freesheet Paper

Sustainable Alternatives


  • Virtualization enables many independent data servers to run software and/or operating systems on one physical server.30 This technology allows companies to greatly reduce the number of physical computer servers needed and better utilize each server; with virtualization, each machine can run at 80% rather than 10% capacity.31 Virtualization reduces material waste, electricity use, space, costs, and heat generation, benefiting both the environment and a business’s budget.30
  • Data center energy efficiency can be increased by utilizing combined heat and power systems to recycle excess heat.32
  • Multi-function office equipment can reduce energy consumption and waste. For example, Xerox claims its ColorQube multifunction printer can reduce costs by 62%, waste supplies by 90%, GHGs by 10%, and energy use by 9% over its lifetime.33
  • Video teleconferences can greatly reduce business travel impacts. One study found that a video conference requires 500 times less energy than a business trip including a 1,000 km (663 miles) flight.34 Telecommuting, in which employees work from remote locations, is increasing in frequency. One study found full-time telecommuting could prevent 3,700 lbs of CO2 emissions per employee per year.35

Reduce Energy Consumption

  • If offices used proper power management and completely shut down at night, office equipment energy use could be reduced by 23% and 9%, respectively.10 If every PC in the world were shut down for one night, the energy saved could light up the inside and outside of the Empire State Building for over 30 years.37
  • Energy Star certified computer servers are, on average, 30% more energy efficient than standard servers. If certified servers replaced all new servers sold, annual energy savings of $800 million and greenhouse gas (GHG) emissions reductions equivalent to those of over 1 million vehicles could be realized.38
  • The average computer wastes 50% of its power.39 To improve efficiency, the EPA recommends setting monitors to go to sleep after 5-20 minutes of inactivity, and the system to enter standby after 15-60 minutes.40
  • Standby power accounts for 5-10% of residential energy use, adding up to $100 per year for the average American household. Unplug electronic devices when not in use, or plug them into a power strip and turn the power strip off.41 Turning off a computer when it is not in use can save $50, 505 kWh, and 662 lbs of CO2 per computer annually.11,42

Distribution of Global CO2 Emissions from IT Devices36

Distribution of Global CO2 Emissions from IT Devices

*Including cooling

Take Action

  • Recycle your unused electronics. Responsible Recycling Practices (R2) and e-Stewards offer third-party certification for electronics recyclers to ensure the proper disposal of used electronics.43
  • Be an informed shopper. The EPA’s Electronic Product Environmental Assessment Tool (EPEAT) rates the environmental impacts of various computer products across 23 required criteria and 28 optional criteria, including energy efficiency, material toxicity, and recyclability.44
  • The average American uses 434 pounds of paper each year, and 45% of printed paper in offices is discarded by the end of the day. Save resources by printing double-sided on recycled paper, or by simply not printing.45,46,47
  • Printers, copiers, and fax machines can use significant amounts of electricity, even in standby mode. Reduce office energy consumption by purchasing Energy Star certified products, consolidating multiple devices into all-in-one equipment, and turning off devices when not in use.48
  1. Natural Resources Defense Council (2014) America’s Data Centers Are Wasting Huge Amounts of Energy.
  2. EIA (2016) Monthly Energy Review May 2016.
  3. U.S. EPA Energy Star Program (2008) EPA Report to Congress on Server and Data Center Energy Efficiency Public Law 109-431.
  4. U.S. Department of Energy (DOE), Energy Information Administration (EIA) (2016) Commercial Buildings Energy Consumption Survey 2012.
  5. U.S. Department of Commerce (2013) Exploring the Digital Nation: America’s Emerging Online Experience.
  6. Gartner (2016) “Gartner Says Worldwide Smartphone Sales Grew 9.7 Percent in Fourth Quarter of 2015.”
  7. International Data Corporation (2011) “Android Rises, Symbian and Windows Phone 7 Launch as Worldwide Smartphone Shipments Increase 87.2% Year Over Year, According to IDC.”
  8. U.S. EIA (2008) 2005 Residential Energy Consumption Survey.
  9. U.S. EIA (2013) 2009 Residential Energy Consumption Survey.
  10. Kawamoto, K., et al. (2001) Electricity used by office equipment and network equipment in the U.S.: Detailed report and appendices. U.S. DOE, LBNL.
  11. EPA (2015) eGRID 2012 Summary Tables.
  12. Energy Star (2013) “Office Equipment Calculator.”
  13. Park et al. (2013) Efficiency Improvement Opportunities for Personal Computers: Implications for Market Transformation Programs.
  14. Roth, K., et al. (2002) Energy consumption by office and telecommunications equipment in commercial buildings, Volume 1: Energy Consumption Baseline. U.S. Department of Commerce, National Technical Information Service.
  15. Keoleian, G. and D. Spitzley (2006) Life Cycle Based Sustainability Metrics. Sustainability Science and Engineering.
  16. U.S. EPA (2016) Documentation for Greenhouse Gas Emissions and Energy Factors Used in the Waste Reduction Model.
  17. United Nations University (2015) The Global E-Waste Monitor 2014.
  18. U.S. Government Accountability Office (2008) Electronic Waste; EPA Needs to Better Control Harmful U.S. Exports through Stronger Enforcement and More Comprehensive Regulation.
  19. Kahhat and Williams (2012) “Materials flow analysis of e-waste: Domestic flows and exports of used computers from the United States” Resources, Conservation and Recycling, 67: 67-74.
  20. U.S. International Trade Commission (2013) Used Electronic Products: An Examination of U.S. Exports.
  21. Electronics Take Back Coalition (2014) Facts and Figures on E-Waste and Recycling.
  22. Food and Agriculture Organization of the United Nations (FAO) (2016) FAO Yearbook of Forest Products 2014.
  23. FAO of the United Nations (2000) FAO Yearbook of Forest Products 2000.
  24. Buongiorno, J., et al. (2012) Outlook to 2060 for World Forests and Forest Industries: A Technical Document Supporting the Forest Service 2010 RPA Assessment.
  25. Conservatree (2012) “Trees into Paper.”
  26. U.S. EPA (2010) Available and Emerging Technologies for Reducing Greenhouse Gas Emissions from the Pulp and Paper Manufacturing Industry.
  27. U.S. EPA (2016) “Greenhouse Gas Equivalencies Calculator.”
  28. Gard, D. (2001) Digital Libraries and the Environment: A Comparative Life Cycle Energy Analysis. CSS01-15.
  29. Environmental Paper Network (2016) “Paper Calculator 3.2.1.”
  30. Energy Star (2013) “Server Virtualization.”
  31. Ruest, N. & D. Ruest (2009) Virtualization, A Beginner’s Guide. McGraw-Hill Osborne Media.
  32. U.S. EPA (2008) The Role of Distributed Generation and Combined Heat and Power Systems in Data Centers.
  33. Xerox (2009) “Breakthrough Xerox Multifunction Printer Cuts Cost of Color Pages by up to 62 Percent; Reduces Waste by 90 Percent.”
  34. Toffel, M. & A. Horvath (2004) Environmental Implications of Wireless Technologies: News Delivery and Business Meetings. Environmental Science and Technology, 38(11): 2961-71.
  35. Roth et al. (2008) The Energy and Greenhouse Gas Emission Impacts of Telecommuting in the U.S.
  36. Gartner (2007) “Conceptualizing ‘Green’ IT and Data Center Power and Cooling Issues.”
  37. Alliance to Save Energy (2009) PC Energy Report, United States, United Kingdom, Germany.
  38. Energy Star (2013) “Enterprise Servers.”
  39. University of Michigan, Planet Blue (2013) “Common Sustainable Computing Myths.”
  40. Energy Star (2013) “Computer Power Management Savings Calculator.”
  41. U.S. DOE (2012) “3 Easy Tips to Reduce Your Standby Power Loads.”
  42. Bray, M. (2008) Review of Computer Energy Consumption and Potential Savings.
  43. U.S. EPA (2013) “Certification Programs for Electronics Recyclers.”
  44. EPEAT (2012) Choosing the Right Electronics Infographic.
  45. U.S. EPA (2015) Advancing Sustainable Materials Management: Facts and Figures 2013.
  46. U.S. Census Bureau (2013) Population Clock.
  47. Environmental Paper Network (2008) Increasing Paper Efficiency.
  48. U.S. DOE, LBNL (2013) “Home Energy Saver: Home Office Equipment.”
Cite as: 
Center for Sustainable Systems, University of Michigan. 2016. "Green IT Factsheet." Pub. No. CSS09-07.