How clean is your cloud?

GreenPeace has released a report titled "How clean is your cloud?" analyzing the environmental cost of this huge data-centers that every day mange our datas but, indeed, use not clean energy.
They analyzed 80 data-centers of the 14 biggest IT companies. The percentage is referred to the Clean Energy Index (elaborated by GreenPeace) basing to the demand of energy and the percentage of green one.

1. Yahoo! (56,4%);
2. Dell (56,3%);
3. Google (39,4%);
4. Facebook (36,4%);
5. Rackspace (23,6%);
6. Twitter (21,3%);
7. HP (19,4%);
8. Apple (15,3%);
9. Microsoft (13,9%);
10. Amazon Web Services (13,5%);
11. IBM (12,1%);
12. Oracle (7,1%);
13. Salesforce (4,0%).