The main different for green data center compare to others is the use of PUE. Below is the detail about PUE.
Power usage effectiveness (PUE) is a measure of how efficiently a computer data center uses its power; specifically, how much of the power is actually used by the computing equipment (in contrast to cooling and other overhead).
PUE is the ratio of total amount of power used by a computer data center facility to the power delivered to computing equipment.
An ideal PUE is 1.0. Anything that isn't considered a computing device in a data center (i.e. lighting, cooling, etc.) falls into the category of facility power usage.
Which should we use for GBI NRNC : Data Center?
Use BEI or PUE if either building or data centre proper energy use constitutes more than 75% of the total energy use. (If building more than 75% - BEI, if Data center more than 75%-PUE, )
Otherwise (both less than 75%), calculate both BEI and PUE with the lower point score applicable .
PUE equal to 1 is an ideal case. Average data center design, the PUE = 2.
PUE=1.5 is consider efficient and PUE =1.2 is normally consider very efficient.
Below is some survey for several data center. There is no data center can achieve PUE 1, the highest is only PUE = 1.2.( most green building rated is as highly efficient data center).