The production of hydrogen is already 70-80% efficient. The conversion back to electricity seems like a bigger bottleneck for vehicles at ~40-60%.
Wikipedia claims that fuel cells can hit 85% efficiency by using cogeneration to repurpose the waste heat, so to me it would seem that hydrogen is more interesting at grid scale.
With hydrogen, you're just trading the problem of storing energy for the problem of storing hydrogen, which always leaks and can penetrate and weaken metal storage containers, valves and so on.
Appreciate you sticking up for me, but I didn't interpret the parent's comment as a dig. Just an attempt to add some additional context to the "debate", which is always welcome.
As for what side I am on - you're right that I am excited about hydrogen as an energy storage medium due to its high energy density, and am in favor of developing the technology further. The challenges are real, and I don't know if it will ever be practical for powering personal transportation (though I wouldn't rule it out either), but there are many other applications beyond just cars where that energy density could prove useful.
I do find it disheartening that battery vs. hydrogen has become some sort of holy war instead of viewing them as two complementary technologies.
Indeed. They are complementary. Batteries for rapidly cycling storage where efficiency is important, hydrogen for long term or rarely used storage where efficiency is less important than minimizing capital cost.
