Knowledge Nugget | India’s first hydrogen train: How does hydrogen fuel cell technology work?
India’s hydrogen train is set to launch after approval from the Railway Board. What is the technology behind it? In ‘Beyond the Nugget’, learn about the National Green Hydrogen Mission and check out the UPSC Prelims 2026 question on this topic.
Hydrogen trains are electric trains with an onboard power source, unlike conventional electric trains that are powered via overhead wires. (Image: AwasthiAwanishK/X) Take a look at the essential concepts, terms, quotes, or phenomena every day and brush up your knowledge. Here’s your UPSC knowledge nugget on hydrogen train technology for today.
Knowledge Nugget: India’s first hydrogen train
Subject: Science and Technology
Why in the news?
India steps closer to joining the global league of countries, including Germany, Sweden, Japan, and China, that operate hydrogen-powered trains. In its letter dated May 22, 2026, the Railway Board (RB) approved the introduction of the country’s first hydrogen-powered trainset. Hydrogen trains – often referred to as ‘hydrail’or ‘H-trains’ provide a viable alternative to diesel locomotives on non-electrified railway routes.
Key takeaways:
1. India has one of the largest railway networks in the world. More than 25,000 trains run across India every day. The country’s first hydrogen-powered train will run between Jind and Sonipat in Haryana. It is developed by Chennai-based Integral Coach Factory (ICF). The 10-car hydrogen-powered set will operate at a maximum speed of 75 kmph.
2. Decarbonisation of the railways is a significant step towards attaining the net-zero goal by 2070. Indian Railways under “Hydrogen for Heritage” envisages deploying 35 hydrogen-powered trains on heritage and hill routes across the country.
📉 Knowledge Nugget Quiz: India's First Hydrogen Train
3. Hydrogen trains are electric trains with an onboard power source, unlike conventional electric trains that are powered via overhead wires. They use HFC (Hydrogen Fuel Cell) technology, which generates energy through the electrochemical reaction of compressed hydrogen with atmospheric oxygen, emitting water vapour as the sole byproduct. This makes the system a zero-emission mechanism at the point of use.
Infographics created by Notebooklm
4. The electricity generated by the fuel cell powers traction systems directly, while onboard batteries store excess energy and provide additional power during acceleration and regenerative braking. Hydrogen trains also employ regenerative braking technology, which captures the kinetic energy (motion energy) generated during braking and converts it into electricity to recharge onboard batteries.
How does the Hydrogen Fuel Cell technology work?
5. HFCs generate high-quality electric power that is clean, quiet, and consistently reliable by converting the chemical energy stored in Hydrogen into electrical energy. The primary components of an HFC are the Membrane Electrode Assembly (MEA) and the bipolar plates.
6. The MEA is where the electrochemical reaction takes place. It consists of a Proton Exchange Membrane (PEM) placed between two catalyst layers – anode (where hydrogen gas enters the fuel cell) and cathode (where oxygen from the air enters). Surrounding them are Gas Diffusion Layers that help distribute reactant gases (hydrogen and oxygen) and remove byproducts (water and heat).
7. According to the US Department of Energy, the PEM —a specially treated material that looks something like ordinary kitchen plastic wrap—conducts only positively charged ions and blocks the electrons. The PEM is the key to the fuel cell technology; it must permit only the necessary ions to pass between the anode and cathode.
8. First, hydrogen fuel (H2) is passed through the anode and is split into protons (H+) and electrons (e-) via oxidation using a catalyst. Then the PEM allows only protons to pass through to the cathode and blocks the electrons.
What is the significance of hydrogen trains for India?
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9. Electrons flow through an external circuit, generating electricity. At the cathode, oxygen (O2) from the air interacts with the catalyst and undergoes reduction. Subsequently, Oxygen reacts with the protons that have passed through the membrane, and the electrons from the external circuit to produce water (H2O).
10. The bipolar plates facilitate gas distribution, electron conduction between cells in a stack, and heat management. This continuous electrochemical process converts the chemical energy of hydrogen directly into electrical energy with water vapour as the only byproduct.
11. This continuous process can generate energy as long as fuel and oxidants are supplied. Due to their operation via electrochemical reactions, HFCs have no moving parts, making their operation silent and highly reliable.
BEYOND THE NUGGET: National Hydrogen Energy Mission
1. The National Green Hydrogen Mission was approved by the Union Cabinet in 2023, recognising the role of Green Hydrogen in India’s ambitions of energy independence by 2047 and Net Zero by 2070.
2. The mission aims to build capacity to produce Green Hydrogen at least 5 MMT (Million Metric Tonne) per annum by 2030, with potential to reach 10 MMT per annum with growth of export markets.
3. The Mission supports the replacement of fossil fuels and fossil fuel-based feedstocks with renewable fuels and feedstocks based on Green Hydrogen. This includes the replacement of Hydrogen produced from fossil fuel sources with Green Hydrogen in ammonia production and petroleum refining, the production of steel with Green Hydrogen, and the use of Green Hydrogen-derived synthetic fuels (including Green Ammonia, Green Methanol, etc.)
| Types of Hydrogen | |
| Grey Hydrogen | It constitutes the bulk of India’s production. It is mainly produced through steam methane reforming (SMR), in which natural gas (methane) is used as the feedstock. The process relies on fossil fuels and releases carbon dioxide into the atmosphere |
| Blue Hydrogen | Production of hydrogen from coal/natural gas combined with Carbon Capture and Storage (CCS). CCS is a way to catch carbon and trap it beneath the earth. It is different from carbon dioxide removal (CDR) — where carbon is sucked out of the atmosphere. The byproducts, like carbon monoxide and carbon dioxide, are captured and stored. |
| Green Hydrogen | In this, hydrogen is produced from water electrolysis—splitting water into hydrogen and oxygen—by using renewable energy-powered electrolysers. It is considered a virtually emission-free pathway for hydrogen production. |
Post Read Question
Which of the following statements with regard to Green Hydrogen is/are correct? (UPSC CSE 2026)
1. It is decarbonized hydrogen obtained from natural gas reforming combined with carbon capture and storage (CCS).
2. It is produced using electrolysis of water with electricity generated by renewable energy.
3. The National Green Hydrogen Mission of India aims for an abatement of nearly 50 MMT of annual greenhouse gas emissions by 2030.
Select the answer using the code given below:
(a) 1 only
(b) 2 and 3 only
(c) 2 only
(d) 1, 2 and 3
(Note: Answer is as per the Provisional answer key released by the UPSC.)
| Answer key |
| (b) |
(Sources: India’s first Hydrogen train trial run begins; passenger services expected this year, Hydrogen trains for a truly green and sustainable form of transportation, Hydrogen fuel cell vehicles for greener tomorrow
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