That’s actually because trains can get away with batteries. Batteries aren’t a very dense energy storage and you’d never get a commercial plane to be economical with batteries. Similar to how you can have a coal ship or train, but never a commercial plane. Hydrogen is lighter than hydrocarbons by a lot, but volume wise, hydrogen takes up more space. The cryo tanks and fuel cells are heavy.
Germany just announced they will discontinue their hydrogen-powered train service in favor of a battery-based solution due to the higher running cost.
Hydrogen may be an alternative, but it has yet to make continuous, solid financial sense for any type of transport.
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.
That’s actually because trains can get away with batteries. Batteries aren’t a very dense energy storage and you’d never get a commercial plane to be economical with batteries. Similar to how you can have a coal ship or train, but never a commercial plane. Hydrogen is lighter than hydrocarbons by a lot, but volume wise, hydrogen takes up more space. The cryo tanks and fuel cells are heavy.