The overall goals of green computing are similar to that of any other ecologically-friendly endeavor: chiefly, to maximize energy efficiency, reduce the use of hazardous materials, and promote the recycling of obsolete products and waste. Various practices that deliver useful benefits have become popular.
Energy management is often the starting point in implementation of green computing. In line with new ecological awareness, many companies have also come to accept that reduced energy consumption translates not only to reduced greenhouse gas emissions, but reduced operational costs for the business as well. Fortunately, there are steps that can be taken to manage and reduce energy consumption. Servers and entire data centers can be consolidated. The data center can upgrade to energy-efficient servers and high efficiency power supplies, and can employ power management processes and controls that automatically turn off systems after set periods of inactivity. User computers are also high energy consumers. “Fifteen PCs can generate as much carbon emissions as a mid-size car each year. The average PC consumes 588 kilowatt-hours of electricity per year, and wastes almost 400 kWh of that by running at full-power when not in use. Using power management controls on PCs during periods of inactivity can cut energy use on average 60-70 percent” (Klustner, 2008). Desktop computer power supply units (PSUs), which are generally inefficient and dissipate a certain amount of energy as heat, should be replaced with newer models.
Virtualization, of both computer resources and the employee experience, has started to generate significant benefits for green computing. Computer virtualization refers to an abstraction of computer resources --- for example, running two or more logical computer systems on one set of physical hardware. With virtualization, hardware infrastructure is reduced, resulting in reduced energy and cooling consumption. Cloud computing services, relating to the location and ownership of infrastructure, can be purchased from a third-party provider, resulting in economies of scale and significant cost savings. In addition to virtualization of computer resources, virtualization of the employee experience can also drive benefits for the environment, the company and the employee. Telecommuting, teleconferencing and telepresence technologies are good examples of this. These practices can reduce travel costs, increase worker satisfaction and, through a reduction of facilities requirements, reduce energy consumption and generate significant savings through lower overhead costs for office space, lighting, heat, and the like. According to the EPA, the average annual energy consumption for U.S. office buildings is over 23 kilowatt hours per square foot, with heat, air conditioning and lighting accounting for 70% of all energy consumed (U.S. EPA, Office of Air and Radiation, 2008).
Certainly one of the basics of green computing involves recycling. The EPA estimates that as of 2007, some 66 million PCs, 42 million monitors and 25 million printers/faxes/scanners were in storage. The EPA further estimates that only about 18% of these would be recycled, with the rest disposed of in landfills (Tucci, 2008). Recycling computer equipment can keep toxic materials such as lead and mercury out of landfills, and can also replace equipment that otherwise would need to be manufactured, thus reducing further energy requirements. Computer systems that have aged or become obsolete can have their lifecycles extended or re-purposed. For example, older servers can be kept powered off or in standby, and used only during periods of high demand. Older desktops can be used as terminal servers, or can be provided to employees whose jobs do not require high-end computing power. Older computer equipment can also be donated to various charities and non-profit organizations.
Finally, within the realm of green computing, there are many practices and work habits that can be encouraged, or mandated, among employees. Most computer equipment now comes with power management features and they should be activated. Computers, printers and monitors should be turned off when not in use. Printers, and hardcopy print output, can be especially hard on the environment. Users should review documents on screen, rather than printing documents unnecessarily, especially draft versions. Many printers can print double-sided documents, which is also environmentally friendly. Ink-jet printers, though a little slower than laser printers, use 80 to 90 percent less energy (“Go green, save green,” 2010). Many organizations mandate the recycling of paper, which is an excellent practice. Companies should carefully consider the size of computer monitors provided to employees. A large display device, such as a 17-inch monitor, uses 40 percent more energy than a 14-inch monitor. Also, if a monitor is set to display higher resolution, it requires more energy (“Go green, save green,” 2010).