Large organisations such as universities can save up to £13,000 a month in energy costs, thanks to software developed at the University of Liverpool that automatically shuts down computer systems when not in use.

The new software, called PowerDown, turns off computers not in use after a half-hour.

Such software could help universities with PC centres drastically reduce their energy consumption, according to the university researchers. They found that PC centres in libraries open 24 hours could be wasting more than one million hours of  computer power each month because of unused machines left on for long periods.

The University of Liverpool itself provided a successful test case for the software after the research team determined its 1,600 library PCs were using 20,000 kilowatts more energy than needed each week — which amounts to about £2,400 in electricity costs. By installing the PowerDown software, the library has been able to reduce the time in which PCs are left unused by 24 million hours.

“An average PC, left on for 24 hours a day but used for only 40 hours a week, uses around 17 kilowatts of electricity, of which 13 kilowatts is wasted,” said Lisa Nelson of the university’s computing services department. “That figure does not take into consideration other costs such as in air-conditioned buildings, where additional cooling is required to remove the heat created by active computers.”

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