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.