Been thinking about alternative fuel

Originally found in a 4x4 mag I was flicking through and eventually here
http://www.milesmoreonwater.co.uk/hydrogen_cars_1.html

Seems to be a decent idea, but would a hydrogen cell be okay (safe) for green laning / offroading?
The main thing that attracts me is that it doesn't require a gert big gas tank to hold fuel in like lpg, just a water tank. It also seems a little too good to be true, just a couple of quid for the catalyst.
I would imgine that there could be a chance of the ecu needing remapping.
the figures for the oval seem pretty good though

I'm wondering if the fronty would be okay with hydrogen, as I believe that LPG (or is it Bio-fuel) and a fronty dont like each other.

sorry if this has been brought up before...please feel free to move/lock if it has been done already.....(forgot to do a search before i started typing)

edit* DOH there are already two pages of threads on this subject...note to self search forum first then search again. Sorry

my fronty run well on LPG