I drove 1800 miles in a Hydrogen Car

You mentioned a couple of times the source of energy of these vehicles, the fact that it's "renewable", or that it would be green in some way. I am very sceptical. Would you care to make a follow-up video on this topic?

From what I understand, there is a theoretical limit to the efficiency of the conversion of electricity to hydrogen which is fairly low, in other words turning electricity to hydrogen is kind of a waste. Thus the only way to produce hydrogen from electricity that makes sense is to produce it with electricity coming from renewable, green, sources (that's a given, right?) which would be otherwise wasted, because there is almost always a better usage of the electricity produced than storage as hydrogen. An example of a good "source" of energy would be a wind turbine working during the night, when people sleep and the demand on electricity is low.

If you combine the poor efficiency and the low availability of these renewable sources, I don't see how it's possible to imagine replacing even a tiny fraction of all the vehicles of the world with hydrogen vehicles.

Of course you can produce hydrogen with hydrocarbons, but that's not renewable, and it produces a massive amount of CO2