The Microsoft datacenter located in Quincy, WA is an environmentally sustainable facility that runs entirely on hydroelectricity.  But the power source is only one factor that makes this facility "green".  Dave Ohara recently went on a tour of the Quincy datacenter, discussed some of the key design points, and left with some guidance on designing a datacenter that you can apply to your environmental efforts:
Modular and Efficient 
Phased Building
Find the Sweet Spot 
Organize for Collaboration
Monitor and Report
Efficient Commissioning 
Prepare for High Loads 
Reduce Water Use

A new installment of our online-only "Sustainable Computing" column is now available. Check it out for a closer look at the 8 points Dave Ohara learned from the folks at the Quincy datacenter.