Most hydrogen is produced from natural gas
http://www.nationmaster.com/encyclop...gen-production
Why not just use the natural gas for fuel and not bother converting it to hydrogen? Yes, you can make hydrogen by electroylis from water but the reason they make it from natural gas is cost. Perhaps some time in the future there may be cheaper ways to make hydrogen such as biological processes which are under development in labs but so are better batteries for electric cars. Right now LPG is the only practical alternative to petrol and diesel. Anyway, whatever we use, you can bet the govt will put a big tax on it.