Hydrogen is generally very hard to store. Batteries have downsides but apart from them, they do work. Hydrogen can either be stored cryogenically (which is pr

Hydrogen is generally very hard to store. Batteries have downsides but apart from them, they do work. Hydrogen can either be stored cryogenically (which is problematic in a car), or compressed. In the latter case, hydrogen leaks out through the metal (because its atoms are so small) and worse still, causes embrittlement of the metal. So while we know how to build a battery car today, which is safe and stable, it's much less the case for hydrogen. It's not like you can take eg LNG car tech and just fill it with hydrogen.