... the fuel cells. Since existing battery electric is already workable for the vast majority of ranges of actual private transport vehicle needs, which are local in character ...

... and the majority of transport tasks where it is not suited are not efficiently done by private transport vehicles anyway ...

... would the most effective private transport vehicle be a local range battery electric, with range augmentation in the form of a hydrogen, ammonia or direct carbon fuel cell?

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.