What is a Hydrogen Train (Hydrail)?

What is a Hydrogen Train (Hydrail)? Comparing Hydrogen Fuel Cells vs. Diesel and Electric trains. Advantages, range, and the future of zero-emission rail.

What is a Hydrogen Train (Hydrail)?
November 30, 2025 9:29 am
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A Hydrogen Train (Hydrail) is an electric train that generates its own electricity on board using a hydrogen fuel cell, rather than drawing power from overhead wires Catenary or a diesel engine. It is a key technology for decarbonizing non-electrified railway lines.

How It Works: The “Cold Combustion”

  1. Storage: Compressed hydrogen is stored in tanks on the roof of the train.
  2. Fuel Cell: Hydrogen is mixed with oxygen from the outside air. The chemical reaction generates electricity and water.
  3. Propulsion: The electricity powers the traction motors and charges a lithium-ion battery buffer (for acceleration boost).
  4. Exhaust: The only emission is pure water (steam).

Hydrogen vs. Diesel vs. Electric

Where does Hydrail fit in the railway ecosystem?

FeatureHydrogen (Hydrail)Diesel TrainElectric (Catenary)
EmissionsZero (Water only)High (CO2, NOx, Particulates)Zero (at point of use)
Infrastructure CostMedium (Refueling stations needed)Low (Existing stations)Very High (Overhead wires)
Range1,000 km+ (e.g., Coradia iLint)800 – 1,500 kmUnlimited
Efficiency~30-40% (Well-to-Wheel)~35%~95% (Most efficient)

Current Applications

The Alstom Coradia iLint was the world’s first passenger hydrogen train, entering service in Germany. Other manufacturers like Siemens (Mireo Plus H) and Stadler are also deploying hydrogen fleets, particularly for regional lines where electrification is too expensive.

FAQ: Frequently Asked Questions

Q: Is hydrogen safe on trains?
A: Yes. Hydrogen tanks are rigorously tested for crashes. In case of a leak, hydrogen (being lighter than air) dissipates upwards rapidly, unlike leaking diesel fuel which pools on the ground.

Q: Why not just use batteries?
A: Battery trains (BEMUs) are great for short distances (< 100km). For long, non-electrified regional routes (e.g., 600km+), Hydrogen is superior due to faster refueling and longer range.