Originally Posted by Old300D

Presently hydrogen is produced from coal, releasing all the carbon. Still adds to global warming. Using electricity to electrolyze water to make hydrogen is inefficient, as using the hydrogen in an engine or in a fuel cell will result in a net loss of energy. It is lossless (compared to H2 conversion) to directly use electricity to charge batteries or capacitors for use in a vehicle.

Hydrogen is a space and energy inefficient energy storage medium (it is not a fuel as hydrogen does not exist in an unbounded state). Even compressed to a liquid state, hydrogen is 1/4 as dense as gasoline or diesel (or biodiesel). That means for the same vehicle range, one needs a fuel tank at least 4 times as large, and the plumbing to deal with the pressure is expensive and bulky. Hydrogen is extremely small and light; there is no existing storage medium that does not leak -- it also happens to be extremely explosive. Biodiesel cannot be ignited with a lit match. The only realistic storage medium on the technology horizon seems to be microscopic glass balls which can theoretically release H2 at a controlled rate, reducing the leaking phenomenon and the explosion risk. But because of the inefficiency of production and the density issues, it cannot ever be considered as a competitive energy storage medium. These issues cannot be solved with a technological breakthrough due to physics.

It is very frustrating to me to see the public getting distracted with pie-in-the-sky when realistic and feasible energy alternatives exist TODAY in TODAY'S TECHNOLOGY - biodiesel in diesel vehicles.