Energy Saving Facts and Figures

Late in 2006 Megan Miln (née Bray) produced a comprehensive white paper collating all the facts, figures, assumptions, and conclusions from recent energy saving studies. We sponsored Megan's research and present the results below.

We are DssW and we make energy saving sofware for the Mac and iOS.

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Review of Computer Energy Consumption and Potential Savings by Megan Bray.


After lighting, computers and monitors have the highest energy consumption in office environments. Studies have shown that power management of computers and monitors can significantly reduce their energy consumption, saving hundreds or thousands of dollars a year on electricity costs.

The energy consumption of computers and monitors is determined by the amount of energy they require to operate and how they are used. While the energy requirements of a device make an important contribution to its overall energy consumption, the key to reducing energy consumption is changing how devices are used.

Approximately half of all office computers are left on overnight and on weekends. Evenings and weekends account for 75% of the week, so ensuring computers are turned off at night dramatically reduces their energy consumption. Further savings are made by ensuring computers enter low power mode when they are idle during the day.

Power management is a way of ensuring computers and monitors are turned off when not required and in low power mode during idle periods.

Manual power management, which relies on education users to turn off their computers, can achieve impressive results with ongoing education and reinforcement. Alternatively, automatic power management relies on software, or built in energy saving features. Theoretically, automatic power management can achieve 100% power management, with all computers turned off when not required and in low power mode when idle.