Leaving computers on overnight = $2.8 billion a year : Christopher Null : Yahoo! Tech

Leaving computers on overnight = $2.8 billion a year : Christopher Null : Yahoo! Tech:

"...all the power wasted while computers are sitting idle overnight adds up, and one study has finally tried to measure it. The tally: An estimated $2.8 billion wasted on excess energy costs each year in the U.S. alone.

On a CO2 basis, that's 20 million tons of carbon dioxide, about the amount produced by 4 million cars on the road."

for perspective:

"If you run a company with 1,000 PCs left on overnight, you can save about $28,000 a year if they are turned off after hours."