700 BAR - no i'm not talking about spring break

There are currently two major factions when it comes to hydrogen and the pressurization in which it is pumped into the hydrogen fuel cell car.  Hydrogen, unlike Gasoline, isn't a liquid at ambient temperatures and needs to be pressurized in order to get as much of it as possible into something the size of a normal fuel tank.  Conceptually, it's basically the same as a propane tank that you might have under your grill in your backyard. 

Honda and its FCX Clarity fuel cell car uses 350 BAR - a measure of pressure in metric, which equals 5000 PSI (pounds per square inch).  Many early hydrogen fuel cell vehicles, and hydrogen fuel stations, including the one at a Shell station in West Los Angeles, uses this pressure.  Mercedes Benz, in the F-Cell, uses 700 BAR, or 10,000 PSI, which is double the pressurization used by Honda.  Toyota and General Motors, based on the cars I have seen at the Torrance Shell Hydrogen station, also use 700 BAR. 

The theory behind the higher pressures is that you can cram more hydrogen into a smaller amount of space.  Newer hydrogen stations have both 350 BAR and 700 BAR pressures at the pump.  It would seem to make sense that at some point in the future, car companies come to some sort of consensus on a common pressure that all cars run on.  And seeing how newer technology from Mercedes, Toyota, GM and Hyundai are all on 700 BAR, looks like the future may be gravitating in this direction.