Yeah. It looks pretty cool. There is something satisfying about a complex mechanical mechanism. However, in its current form it is not the future. Combustion engines in general are not going to be the future. Hydrogen is a joke. Not energy dense enough. And expensive to make (energy wise). It also needs a vast network of gas stations.

Who says so? Batteries been available for hundred years yet we keep talking about fusion being the future, and we have fission. Which both drive turbines, which are a thing from the past? No? What is joke and when?

To me is a joke that we keep heating water to move magnets to get energy in 2024 with all the quantum entanglement, Johnson teleportation, lasers, etc. engineering magic happening around. And we do what? heat water to move magnets to squeez energy? So why is then hydrogen bad, just because it goes boom? Plenty of things we use daily go boom now and then, not meaning recent news, but in general.

I also invite you to take a look at the Tokamak and then try to argue again that metal tubes wired around to pump liquids and do some combustion is not the future.

Compressed hydrogen has low enough density that even at dangerously high pressures it would take up most of the luggage & passenger areas of a car, just to get mediocre range. Liquid hydrogen has better density (roughly 2x), but it's still not great, & you're dealing with a cryogenic propellant that's constantly venting explosive gas (so it runs out of gas when parked for ~3 days, can't be parked in an enclosed space, & still doesn't deliver impressive range). I'm all for using hydrogen for things in general, but as I understand it there are hard physical limits that make it a poor choice for personal motor vehicles as we understand them today (size, safety & range in particular).

Methanol or renewable synthetic gasoline seem like they'll always outperform hydrogen for ICE cars.

Hydrogen airships would be cool though & we could make them safe with modern technology (both preventing fires & making the passenger compartment an under-slung survival cell with parachutes & giant airbags so a catastrophic loss is survivable)

All of this is very interesting, and I'm aware of the many challenges hydrogen is still facing./ But I think material knowledge is also improving rapidly, so perhaps we'll see some very nice new lattices to safely contain it in some compartmentalized manner. But what I meant about hydrogen was not really about cars, but heavy industry. Heavy industry is hungry and will produce its own solar, then dump it in hydrogen and burn it overnight. Then it can feed the electric cars perhaps.