> With hydrogen based car though it's an almost exact copy of the ICE car. It's got a big, hot finicky fuel cell under the hood that requires ongoing highly qualified maintenance.
That's utter bullshit. A fuel cell is literally an electrochemical system no different than a battery.
A fuel cell is not a closed system, a battery is. A fuel cell need a supply of hydrogen (obvious) and oxygen from the air and in return it produces heat, water, and some electricity (with pretty terrible efficiency). A battery produces electricity and heat (depending on load).
That's widely inaccurate. The fundamental advantage of an electrochemical system is that you are no longer limited by Carnot's theorem in the same way as heat engines. As a result, the efficiency of both systems can be the same. Not to mention you don't have to deal with all that heat either, making operation much simpler.
In the end, a fuel cell is basically a metal-air battery, and has the same level of efficiency.
Except it does not have the same efficiency when you compare how many kWh you have to feed into an electrolyzer so that you make 1 kWh of electricity out of the fuel cell in a car.
You cannot get every kWh from renewable energy into a BEV no matter what. The intermittency problem guarantees that a lot of it will be lost or never captured. An idea like hydrogen that lets you store energy for long periods lets you utilize energy that otherwise would be lost. As a result, the full cycle efficiency of a hydrogen car can exceed that of a battery car.
'... lets you store store hydrogen for long periods of time' is not as easy as you suggest. It's well known that hydrogen makes most (possibly all) metals become brittle over time. Hydrogen also leaks easily through metals because the atoms are so small. Consequently very expensive tanks are require to '..store hydrogen for long periods of time...'. It's a near certainty that storing energy for long periods is more effectively done with Megapacks of batteries. A little googling will show that Tesla (and others) are now making a booming business in this technology whereas, to my knowledge, not one substantive hydrogen storage plant has been built to date, because of the problems stated above.
> It's well known that hydrogen makes most (possibly all) metals become brittle over time.
It's not "well known." In fact, this is bullshit. Only some metals have this problem. Even then there are ways of preventing the problem via coatings and the like. Nor is it even necessary, as geological formations can be used to store hydrogen in the same way we store natural gas.
You are simply reading too much pro-BEV propaganda. These are solved or are easily solvable problems.
That's utter bullshit. A fuel cell is literally an electrochemical system no different than a battery.