"How dirty is your data?" (http://macte.ch/jYBqf) is a new report from the Greenpeace environmental agency on the energy choices made by IT companies including Apple, Akamai, Amazon.com (Amazon Web Services), Facebook, Google, HP, IBM, Microsoft, Twitter, and Yahoo. Apple doesn't fare well in the report.

"How dirty is your data?" highlights the need for greater transparency from global IT brands on the energy and carbon footprint of their Internet infrastructure. With more of our daily rituals taking place online than ever before, the information we generate -- videos, pictures, emails, status updates, news, tweets -- ends up in giant data storage facilities called data centers, such as the one Apple is building in North Carolina.

Packed full of computer servers, these facilities consume huge amounts of electricity, amounting to 1.5 to 2% of global energy demand (3% in the U.S.) -- and it's growing at a rate of 12% a year, according to Greenpeace. If the Internet was a country, it would rank fifth for the amount of electricity usage, just below Japan and above Russia, the environmental group says.

"But unlike geographical states, the Internet's data centers can be found all over the world, clustering in locations that offer strong tax incentives and cheap, but often dirty, electricity," says Greenpeace. "The $1 billion Apple iData Center in North Carolina, expected to open this spring, will consume as much as 100 MW of electricity, equivalent to the electricity usage of approximately 80,000 homes in the U.S. or over a quarter million in the E.U.. The surrounding energy grid has less than 5% clean energy, with the remaining 95% coming from dirty, dangerous sources like coal and nuclear."

Apple received the lowest clean energy index of all companies rated with just a 6.7 % rating. Yahoo topped the list with 55.9% clean energy, while Google and Amazon also ranked highly with 36.4% and 26.8% respectively. One of the few bright notes: Apple received a higher score in the categories of transparency and mitigation strategy.

Greenpeace acknowledges that cloud computing can save energy in many ways. However, the group says that it also runs the risk of ignoring the impact of clean vs. dirty energy.