The basic problem with hydrogen fuel cells is that it takes
as much energy to produce the hydrogen as is utilized from the hydrogen. Therefore a hydrogen fuel cell is an merely
an energy carrier.
That all depends on where you get the energy to produce hydrogen. All we need is a type of filter that will separate the different elements right out of the air. Shouldn't be too hard.
Hydrogen is a fascinating subject. We have research that is promising to force some algae to produce H2 instead of O2, and they are in the efficiency stage, not the basic stage.
http://www.wired.com/news/technology/0,70273-0.html?tw=rss.index
H2 can be stored safely in a Borax compound and has the pentagon interested, as the stored fuel is not explosive. Daimler Chrysler demonstrated a town and county Natrium in 2002 for the pentagon.
http://www.csmonitor.com/2002/0131/p13s01-stss.html
DK