eBay has decided to run a full data center on Bloom Energy fuel cells and use the grid only for backup power. Once installed in mid 2013, the 6MW array will be the largest non-utility fuel cell installation.
Fuel cells convert a fuel, such as natural gas or hydrogen, into electricity in a chemical reaction rather than burning the fuel. Bloom Energy's fuel cells, which each take up about a parking space, are solid oxide fuel cells which use the heat generated by the fuel-to-electricity conversion to improve the efficiency.(Makes a lot of sense if they can run their servers directly off DC power).
TR: EBay Goes All in with a Fuel Cell Powered Data Center