Green data centers: They're the future
Data centers are ludicrously energy hungry. Powering thousands of racks of servers, keeping facilities cool, providing water for employees, lighting the building--it's an energy efficiency nightmare to operate one.
Lots of companies have looked for cost-saving measures wherever possible, which in this case has had the side effect of being great for the environment. Data centers are increasingly powered by renewable resources like solar, wind, geothermal, and hydroelectricity. Add to that some innovative cooling solutions and you have a new generation of data centers on the rise that are some of the greenest facilities in the world.
Note: Ratings like Power Usage Effectiveness (PUE--the lower the better, with 3.0 being inefficient and 1.0 being incredibly efficient) and the US Green Building Council's Leadership in Energy and Environmental Design (LEED) certification are two ways to tell how efficient a data center is. You'll see both of these figures referenced in relation to these 20 green data centers.