IIRC, right now, electrolysis to produce the necessary amount of hydrogen takes more energy than you get from hydrogen.

It always will. It is called the Second Law of Thermodynamics.
I am substancially rewriting this article to provide better information on this issue.
Quasarstrider 16:17, 5 Apr 2005 (UTC)
I meant in a more realistic terms. Hydrogen doesn't have much potential energy. Well, except for fusion, but that requires too much energy to make into a practical fuel equivalent. Electric cars are the future, not hydrogen cells.

This article should be merged with Hydrogen economy. Ultramarine 22:41, 4 Apr 2005 (UTC)

Agreed. I only noticed that page existed after I already wrote this information here. I moved all the text from here to that page.
Quasarstrider 16:17, 5 Apr 2005 (UTC)