How powerful is a hydrogen fuel cell?

Question

Or really, how powerful could they get?

Answer 1

Much reading available through

http://www.dmoz.org/Science/Technology/E...

Measuring power as energy per mass, it must be pretty good, because they used it for space missions, where mass costs a *LOT* of money.  

The other  way to measure power would be energy per space.  Hydrogen takes up lots of space for what it weighs, so may not be *as* good on this measure.

Answer 2

That question doesn't make much sense.  What do you mean by powerful?  A hydrogen fuel cell is basically a battery that you "recharge" by replacing the hydrogen (refilling it).  It produces electrical power, so there isn't really a limit on how much electrical power one could produce other than how much hydrogen can be carried.