Everybody here should know the concept of perpetual motion. Also, I can assume that it is known that this concept is purely hypothetical. That's too bad, because otherwise we might have had the perfect solution for data centers at hand: the perpetual motion of heat-to-electricity for servers, that again generate the heat.
Applied Methodologies Inc. have explored this idea with a new design that uses heat from IT equipment to generate power for the servers and switches in a data center. They are not the first, and while this looks very simple (heat, after all, is energy. And servers need energy) there is one humongous catch: the heat generated by data centers is typically too little to harness effectively.
However, it seems that AMI is ready to put its idea into practice and is looking for potential OEMS to help them with their so-called Thermoelectric Generation Systems. The company says a 1U TGS server can generate 10 volts and 5 amps at current efficiency levels. It is proudly showing off its prototypes on Youtube:
My gut tells me it is a bit too convuluted to be practical, just as the 19th century 'perpetually moving' devices designed by inventors tended to be. But still, it is an important area to explore. Besides, if all else fails you can always use the heat to warm the company cafetaria.