"Greenpeace released its latest report today asking, 'How clean is your cloud?' The annual report examines the server farms built by the largest Internet companies -- including Amazon, Apple, Facebook, Google, Microsoft and Yahoo -- and ranks them according to how efficient their cloud facilities are, and where they get their electricity."
"Yahoo -- which has struggled to please investors in recent years -- was the only major Internet company in the study to get most of its electricity from renewable or clean energy sources, according to the report.
Many server farms can consume as much electricity as a small city. Some of the largest consume as much electricity as 180,000 homes."