China's propaganda is indeed sometimes as bad as US propaganda.

In the video that you show, the solar energy is creating electricity.
This electricity is converted to hydrogen.
There are different ways to store hydrogen, but they are not that expensive.

To convert hydrogen back to electricity you need some metal that does not breakdown from electricity.
That is usually an expensive noble metal, like palladium or platinum.
That is the part that broke down in the car.

Maybe later versions have ceramic components?
That could make a new version cheaper.