Ever worried about how to handle a 20 Petabyte (that's roughly 21 million Gigabytes) digital archives? Shane Hathaway has. As far as I can see it's only a research project without any beta code so far but it sure is geekily exciting in a way.
He mentions one of problems with this and for that you don't need a double PhD to understand:
"Power is a large concern. 20 PB worth of spinning hard drives would incur a power bill in the neighborhood of $100,000 per month. Over time, that power bill could even exceed the hardware acquisition cost."
Even though it's just a rough estimate it's still quite fascinating.