IT energy management
IT energy management is the analysis and management of energy demand within the information technology arena. IT energy demand accounts for approximately 2% of global CO2 emissions, approximately the same level as aviation.[1] IT can account for 25% of a modern office building’s energy cost.[2]
The main sources of IT energy demand are PCs and Monitors, accounting for 39% of energy use, followed by data centers and servers, accounting for 23% of energy use.[3]
PC power management
Research shows that in the US, 50% of PCs are left on overnight, resulting in an estimated annual energy waste of 28.8 billion KWH, and a cost of $2.8 billion to the economy. User behaviour is slightly different in Europe, with approximately 28% of PCs being left on overnight in the UK, resulting in an estimated energy loss of 2.5 billion KWH, costing £300 million. In Germany, with approximately 30% of PCs left on overnight, it is estimated 4.8 billion KWH of energy are wasted each year, costing €919 million[4]
User behaviour is a big factor in energy waste by PCs, through people not turning off their PCs when they leave work, but network processes also compound the problem.
Managing energy use by PCs attached to IT networks is difficult due to network processes making a PC’s internal power profiles ineffective. Because processes on the network are constantly providing inputs to the PC, the machine fails to recognise that there is no user input, and fails to go into its low-power mode.
PC power management is a classic problem of distributed demand management, where individual devices which have a relatively low power demand result in a very large cumulative energy demand.
Addressing this problem requires specialised power management software. These tools are highly effective at cutting power demand by PCs,[5] saving of 40% on average can be made using this software. Typical savings per PC are $35 and 200 kg CO2 per PC per year.[6]
Energy Efficient Ethernet
Energy Efficient Ethernet (IEEE 802.3az) could reduce the energy use of networking equipment. In 2005, all the network-interface controllers in the United States (in computers, switches, and routers) used an estimated 5.3 terawatt-hours of electricity.[7] According to a researcher at the Lawrence Berkeley Laboratory, Energy Efficient Ethernet could save an estimated $450 million a year in energy costs in the U.S.[8] With most of the savings from home computers ($200 million), and offices ($170 million), and the remaining $80 million from data centers.[8] Energy efficient Ethernet saves energy by allowing network links to either go into a low power sleep mode or run at a slower rate when there is no data. It also defines lower power signaling for use on higher quality cables.
Server and data center power management
Servers and data centers account for 23% of IT energy demand.[3] Data centers are a point source energy demand where a lot of focus has been on input control to reduce the power demand of cooling systems, and to make power inputs to servers themselves more efficient.[clarification needed]
As computing hardware becomes smaller and less expensive, energy costs constitute a larger portion of server or data center costs.[9]
Server and data center systems tend to be designed with significant computational redundancy. Typically, an individual server will only operate at around 18% of its capacity.[citation needed] The reasons for this are largely historical, and with current technology, this level of redundancy is not required.[citation needed]
This feature of data centers and servers allows major energy efficiency gains to be made through optimisation of servers. This is typically done by doing diagnostic tests on individual servers and developing a model for a data center’s energy demand using these measurements.
By analysing every server in a data centre, server power management software can identify servers that can be removed. It also enables servers to be virtualized, processes to be consolidated to a smaller number of servers, and servers with a predictable cyclical power demand to be fully powered down when not in use. Active power management features are also included which put remaining servers into their lowest power state that allows instant wake-up on demand when required.
This approach to server power management has the potential to make very large energy savings in data centers and server rooms.
Energy efficiency benchmarks, such as SPECpower, or specifications, like Average CPU power, can be used to comparing server efficiency and performance per watt.
Siting of data centers can increase or reduce their energy use. Siting in areas where climate allows air-cooling and lots of renewable electricity is available nearby can reduce the energy used and resulting environmental effects.
Organisations and resources for IT energy management
There are a number of industry associations and policy organisations whose work on promoting energy efficiency includes providing resources and information on IT energy management. These include:
- The Green Grid
- Alliance to Save Energy
- Climate Savers Computing Initiative
- 2Degrees (Low Carbon ITC Network)
See also
References
- ^ Gartner Press Release April 26, 2007, Gartner Estimates ICT Industry Accounts for 2 Percent of Global CO2 Emissions http://www.gartner.com/it/page.jsp?id=503867
- ^ Gartner Inc., “IT Vendors, Service Providers and Users Can lighten IT’s Environmental footpint” Simon Mingay, December 5, 2007
- ^ a b Steve Kleynhans, VP Computing, Gartner presentation “the Green PC Environment” - presentation, New York, November 2007
- ^ PC Energy Report 2009, United States, United Kingdom, Germany, Alliance to Save Energy & 1E March 2009 http://www.climatesaverscomputing.org/docs/1E_PC_Energy_Report_2009_US.pdf
- ^ 451 group Market Insight Service Analyst: Andy Lawrence Date: 13 May 2009
- ^ How Dell Does IT: Energy Efficiency, Dell Cuts energy costs by up to 40% with a new power management plan http://www.dell.com/content/topics/global.aspx/casestudies/en/emea/eu/fy2008_q3_id688?c=us&l=en&s=gen
- ^ "IEEE Spectrum: Energy-Efficient Ethernet". Spectrum.ieee.org. Retrieved 2010-02-11.
- ^ a b "Energy-efficient Ethernet standard gains traction". EETimes.com. Retrieved 2010-02-11.
- ^ Template:Cite article