Photos: Fujitsu unveils king-size fuel cell

A proton exchange membrane (PEM) hydrogen fuel cell, king-size. Fujitsu inaugurated this fuel cell at its Sunnyvale, Calif., campus on Friday. The fuel cell sits in the parking lot and looks like a pair of giant green dumpsters. Made by UTC Power, the fuel cell will produce 200 kilowatts of power, which is enough to power half of the cooling needed in Fujitsu's data center.

The heat harvested from the reactions required to turn hydrogen into electricity will be used by Fujitsu in the buildings too. Right now, the fuel cell system is 50 percent efficient. That puts it on par with conventional power plants; with conventional systems, over half of the power gets lost in transmission lines or as waste heat before it gets to your house. By capturing more heat, the efficiency of the fuel cell can be raised to 85 percent, says UTC.