It has been found out that each PC left turned on overnight and at weekends costs British businesses £17 a year which in total makes up £300 million annually. Still, the situation is not as bad as it is in the US, where half of corporate computers are left turned on overnight and US firms pay extra $2.8 billion a year. 

Sumir Karayi, chief exec of 1E power management firm, says the real figure could be even higher. He suggests, “Shutting down PCs when not in use will help businesses to significantly reduce costs while preventing tons of CO2 from being emitted into our atmosphere." Gartner stated that the IT and telecoms industry was generating 2 per cent of world carbon emission, while all the PCs and monitors accounted for 39 per cent of the total amount.

Two years ago Harris Interactive had found out that half of British computers were left on overnight. The result was revealed after polling 2,000 people in the UK.