Diesel trains have been used for the better part of a century on pretty much every railway of note because they're very cheap. Moves to add electric power to railway lines have taken place, but it's hugely expensive: Alstom puts the figure at €1.2 million per 1 km, or $1.4 million per 0.6 miles. Of course, these days, most governments simply can't afford to bankroll large-scale electrification.

Battery-electric trains, too, are out of the question, thanks to the sheer size, weight and cost of a battery that could run for 1,000 km on a charge. Hydrogen as a fuel, on the other hand, behaves pretty much like diesel, has a much higher energy density and it only takes 15 minutes to refuel a tank. And on trains, where weight and aerodynamics are less of an issue, you can add more tanks depending on your needs.

From the outside, you certainly wouldn't have guessed that the Coradia iLint is a hydrogen train, looking just like its diesel-powered predecessor. But when it rolls up to approach you, you'll notice how deathly quiet it is: Aside from a little whine from the engine, you'll barely hear it. In fact, the squeak of the wheels against the cold morning tracks were louder than the train itself. Only the air brakes, which are as noisy here as on every other train, are noticeable.

The train looks and feels like pretty much every other European multi-height train I've ever sat in. There are lower decks for wheelchairs, bicycles and passengers, with steps to raised sections with additional seating. The only difference you'll spot is the livery outside, which boasts of its fancy new power supply, and the upholstery, which is patterned with H2 symbols.

I rode on the prototype along Alstom's test track, which surrounds its enormous train factory in Salzgitter, Germany. Because the track isn't that long, the iLint prototype is limited to 80 kmph, but on a real railway line near Bremerhaven, its top speed is double that. Plus, the prototype has slightly smaller fuel tanks: It can only run 800 km on a tank, compared to the 1,000 km of the production model.

The train is based on Alstom's existing Coradia Lint diesel trains, but with an engine system similar to any FCEV (fuel cell electric vehicle). The wheels are driven by an electric motor embedded in the chassis, and beside it is a battery that maintains a constant flow of power. Above the cab, meanwhile, are the hydrogen storage tanks, and the fuel cell is in the roof in the middle of the train.

One other difference between iLint and the production model is the fuel cell wasn't covered in sound insulation. Intentionally choosing to sit beneath it, then, meant that I could hear it in operation as we rode along the track. And, if you're curious, it sounded like a bunch of demons screaming at each other from the other side of an airplane hangar. I am told, however, that the production models will not make this sound, probably to avoid freaking out the passengers.