Which country launched the world's first fleet of hydrogen-powered passenger…

Concept — A hydrogen-powered train stores hydrogen in on-board tanks and feeds it to fuel cells, where hydrogen combines with oxygen from the air to produce electricity, leaving water vapour as the only exhaust. That electricity drives the traction motors and charges a battery that also recovers braking energy, so the unit needs neither diesel fuel nor overhead wires.

The claim being tested is stricter than "the world's first hydrogen train". A fleet means a group of units taking over the regular, timetabled passenger service on a route together, as against a single prototype making trial or demonstration runs. So the test is: where did several hydrogen units first replace the scheduled service on an entire line?

Application — Germany did this, using Alstom's Coradia iLint. The Lower Saxony transport authority LNVG ordered these units for the Elbe-Weser network north of Bremen, and in August 2022 the operator evb began working the Cuxhaven-Bremerhaven-Bremervoerde-Buxtehude services with them in place of the diesel railcars. Two iLint prototypes had already carried passengers on the same line from September 2018, so the 2022 changeover was the point at which a whole route ran on a fleet of hydrogen trains.

Cross-check — The other three countries also had hydrogen rail programmes, but none had put a group of units onto a scheduled passenger route:

Result — Germany launched the world's first fleet of hydrogen-powered passenger trains.