fuel cells as backup?
 

with all reference to a fuel cell, i have noticed that it is used only as a primary power generating source. why can't it be used as a backup supply? if it has the capacity to take the whole data center off the grid, it can most certainly sustain a data center for some time, can't it? although it is expensive, it is eco-friendly.

fuel cells are still in experimental stages. im not sure if they are successfully introduced in a data center as a primary source let alone as a backup. they are also expensive and they are only advisable in places where the power costs are enormously high.