epirali said:
Again I am a little puzzled...
With the caveat that I'm an old guy who has been reading about hydrogen fuel cells being the coming thing for
decades, the problem is physics and chemistry. Hydrogen is the least dense element and as a fuel source it needs to be compressed enormously, at great energy cost, to be useful as a fuel. Many years ago the solution was supposed to be metal hydrides, which would allow hydrogen to be stored safely in a fairly dense manner. Don't hear about that anymore. Why?
As anyone who has played with hydrogen balloons soon learns, H2 is the smallest molecule of all and is so tiny that it leaks out of most containers readily unless they are very, very robust. Also hydrogen bottles become brittle with age, because hydrogen is quite reactive, and need to be tested, certified, and replaced regularly. Most hydrogen in the industry is currently made from natural gas, meaning it essentially a fossil fuel. So the goal is to make it from water, perhaps with renewable energy. Hydrogen + oxygen is a very exothermic reaction (something like 50 kcal/mol IIRC), which is why it makes such a good rocket fuel. But that also means that it takes a lot of energy to break it down from water. Why not just skip all that, plus energy intensive compression, and just power an EV directly with the electricity?
Fuel cells have been quite expensive to produce and have been quite delicate in use. Getting one to be inexpensive to manufacture and robust enough to last under vehicle conditions has proven to be difficult. That is a technical problem, so it is likely solvable, but it is something that has been hammered on for
decades, without much progress. This is not new stuff, the Apollo space ships used fuel cells but for NASA cost was no object. Consider the progress made in lowering the cost of solar cells over all those years. Fuel cells? Not so much.
Others above have mentioned the enormous cost of installing hydrogen fueling infrastructure. Compare that to electricity, which is everywhere. The cost of EVSEs is utterly trivial by comparison.
These are just some of the practical considerations. The politics of the situation make it clear that that some auto manufacturers are using hydrogen fuel cells as a delaying tactic for pollution and fuel efficiency regulation: "See, we're working on hydrogen fuel cells as the ideal solution. Just a few more years and they'll be the ultimate answer. We promise!" I don't buy it. This is nothing but a scam to delay more rigorous fuel and pollution efficiency requirements by CARB and similar entities.
My 2¢.
