system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: how do hydrogen-powered cars work, and are they a considerable competitor to electric vehicles?

Are hydrogen-powered cars even a thing?
gpt
Hydrogen can be used as fuel for combustion engines that are very similar to the fossil-fuelled ones. But another, less mechanically complex solution is to use hydrogen as fuel for a *fuel cell* which creates electricity that powers the car. So in that case, the car is just a normal EV where the large battery pack is replaced with a hydrogen tank and a fuel cell.