If weight isn’t an issue, then it makes sense to use a system that only costs a fraction of a hydrogen-powered setup.
Trains don’t need to fly. Just pack them full of batteries or - arguably even better - just electrify the line wherever possible.
That’s just not an option for planes, so hydrogen remains a potentially viable approach.
Same goes for large container ships. It won’t make sense to use batteries unless there are significant breakthroughs in capacity technology.
One of the advantages of hydrogen is that tanks and fuel cells can withstand a large number of “charging cycles” much better than batteries. Additionally, for ships, the amount of energy needed to move is so enormous that I fear we’ll have a hard time creating batteries that are feasible for long-distance shipping.
For short distance ferrying (including large, car carrying ferries) on the other hand, Norway has already implemented quite a few electric stretches. The major issue there is building the infrastructure to charge the ferries.
No they can’t, the membranes of fuel cells degrade extremely quickly, as I a couple of 100 cycles before significant efficiency loss. That’s currently one of the biggest issues with fuel cells and one of the biggest areas of research. Currently, batteries are far more reliable as an energy source.
