IT energy management
is the analysis and management of energy demand
Energy consumption is the consumption of energy or power. It is covered in the following articles and categories:* World energy consumption* Domestic energy consumption* Fuel efficiency in transportation* Electric energy consumption* Electricity generation...
within the information technology
Information technology is the acquisition, processing, storage and dissemination of vocal, pictorial, textual and numerical information by a microelectronics-based combination of computing and telecommunications...
arena. IT energy demand accounts for approximately 2% of global CO2 emissions, approximately the same level as aviation. IT can account for 25% of a modern office building’s energy cost.
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.
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
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
PC power management refers to the mechanism for controlling the power use of personal computer hardware. This is typically through the use of software that puts the hardware into the lowest power demand state available...
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
Power management is a feature of some electrical appliances, especially copiers, computers and computer peripherals such as monitors and printers, that turns off the power or switches the system to a low-power state when inactive. In computing this is known as PC power management and is built...
software. These tools are highly effective at cutting power demand by PCs, 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.
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. 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. With most of the savings from home computers ($200 million), and offices ($170 million), and the remaining $80 million from data centers. 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. 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.
As computing hardware becomes smaller and less expensive, energy costs constitute a larger portion of server or data center costs.
Server and data center
A data center is a facility used to house computer systems and associated components, such as telecommunications and storage systems...
systems tend to be designed with significant computational redundancy. Typically, an individual server will only operate at around 18% of its capacity. The reasons for this are largely historical, and with current technology, this level of redundancy is not required.
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 room
A server room is a room that houses mainly computer servers. In information technology circles, the term is generally used for smaller arrangements of servers; larger groups of servers are housed in data centers...
Energy efficiency benchmarks, such as SPECpower
SPECpower_ssj2008 is the first industry-standard benchmark that evaluates the power and performance characteristics of volume server class computers. It is available from the Standard Performance Evaluation Corporation . SPECpower_ssj2008 is SPEC's first attempt at defining server power measurement...
, or specifications, like Average CPU power
The average CPU power , is a scheme to characterize power consumption of new central processing units under "average" daily usage, especially server processors, the rating scheme is defined by Advanced Micro Devices for use in its line of processors based on the K10 microarchitecture...
, can be used to comparing server efficiency and performance per watt
In computing, performance per watt is a measure of the energy efficiency of a particular computer architecture or computer hardware. Literally, it measures the rate of computation that can be delivered by a computer for every watt of power consumed....
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
The Green Grid is a non-profit, open industry consortium of end-users, policy-makers, technology providers, facility architects, and utility companies collaborating to improve the resource efficiency of data centers and business computing ecosystems...
- Alliance to Save Energy
The Alliance to Save Energy is a coalition consisting largely of industrial, technological, and energy corporations. The Alliance states that its mission is to "support energy efficiency as a cost-effective energy resource under existing market conditions and advocate energy-efficiency policies...
- Climate Savers Computing Initiative
The Climate Savers Computing Initiative is a nonprofit group of consumers, businesses and conservation organizations dedicated to promoting smart technologies that can improve the power efficiency and reduce the energy consumption of computers...
2degrees is a U.S. and British owned mobile phone provider operating in New Zealand with 580,112 customers . They launched on 5 August 2009 after 9 years of planning. 2degrees currently offers prepaid and pay monthly mobile services...
(Low Carbon ITC Network)