HYDROGEN, THE NEW MASTER OF RAILWAY?

Written by Amira Balqis, Rachel Kang

You may recall learning about electrolysis in high school — the process of splitting water into hydrogen and oxygen gas. This simple process is actually vital in producing fuel. 

Green hydrogen, generated through electrolysis, is often called the fuel of the future. By using carbon-free electricity sources like solar, wind, or hydro power, the production of green hydrogen remains entirely carbon-free. Today, more and more people are turning to green hydrogen, applying it to everyday uses, including trains.

The Coradia iLint, the world's first passenger train powered by a hydrogen fuel cell, offers hope for reducing pollution and promoting sustainability. Since it emits no carbon dioxide and only water as exhaust, it stands as a cleaner alternative to traditional trains. Built on the Coradia Lint DMU platform, it has a passenger capacity of 300 people, which includes 150 seats. Designed by Alstom, a French multinational rolling stock manufacturer, in Salzgitter, Germany, the train can reach speeds of up to 140 kilometres per hour and travel 600 to 800 kilometres on a full tank of hydrogen.

Alstom Coradia iLint – the world's 1st hydrogen powered passenger train

Delving into its structure, the Coradia iLint traction system consists of two 200kW fuel cell modules, which are located on the roof of two cars. Each cell module includes six sets of fuel cells, cooling systems, injection and air filtration. Additionally, liquefied hydrogen tanks are situated on the roof. The train is also equipped with a traction electric motor, an AC/DC traction converter, an auxiliary converter and two lithium-ion batteries with a total capacity of 220 kW, which are from Akasol, a German manufacturer of batteries for electric vehicles. These components are all installed in the undercar space. 

In the fuel cell, hydrogen undergoes a “cold combustion reaction” with oxygen, which is a reaction between H2 and O2 to generate electrical energy without evolution of heat. During the process, water in the form of condensate or steam is produced. Excess energy produced through the reaction and during regenerative braking ( a technique to capture energy that the vehicle has due to its motion) will be stored in the batteries. The excess heat produced is utilised to warm the interior of the train. The vehicle is fitted with two HVAC (heating, ventilation, and air conditioning) units, supplied by the global technology company Spheros.

There’s more than just having hydrogen as an alternative to the regular cell. One of the key benefits of hydrogen fuel cell usage is of course reducing the carbon emission as the electrolysis of green hydrogen only has water vapour as its side product. Hydrogen fuel cells are also proven to have a short refuelling time. As hydrogen is stored as a compressed gas, refuelling the hydrogen tanks involves simply transferring the gas at high pressure which can be done within minutes compared to electric batteries which require a longer time to be fully charged. 

Next, they make no engine noise. Unlike internal combustion engines which involve the burning of fuel and noise production sourced from explosions within the engines itself, fuel cells generate electricity silently as there are no moving parts involved in the energy production process. Also, integrating fuel cells into existing railway infrastructure requires minimal modifications where the train can run electrified or non-electrified so more cost can be saved.

Nevertheless, a potential drawback that could occur includes specific conditions (high pressure or low temperature) for onboard fuel storage  can lead to high expenditure on storage vessels as well as  increased energy consumption for compression or refrigeration of hydrogen for refuelling purposes to keep the engines running. Subsequently, since it might take some time for the world to be fully equipped with a hydrogen-based ecosystem such as refuelling stations, initial investment for hydrogen train technology can be high, as fuel cells and hydrogen storage systems are still relatively expensive due to the lack of infrastructure.

As a whole, hydrogen is getting a whole wide attention globally due to its vast potential in changing the future of many industries, especially transportation. Usage of hydrogen, specifically green hydrogen as the main fuel source will become a paradigm shift towards a more sustainable future. Hydrogen fuel cells will undoubtedly be a viable solution in reducing the industry’s carbon footprint and can accelerate countries’ effort around the globe in achieving a greener future together. Despite the challenges in infrastructure development and hydrogen production, a continued advancement will pave the way for a cleaner, more efficient rail system in the coming decades. It is safe to say that the future of transportation may well lie in hydrogen’s potential, making now the time to invest in and develop this promising technology. 

Reference

1. https://www.alstom.com/solutions/rolling-stock/alstom-coradia-ilint-worlds-1st-hydrogen-powered-passenger-train 

2. https://en.wikipedia.org/wiki/Alstom_Coradia_LINT#iLint 

3. https://rollingstockworld.com/passenger-cars/coradia-ilint-hydrogen-trains-have-been-put-in-commercial-operation-in-germany/ 

4. https://encyclopedia.pub/entry/49766 

5. https://www.sciencedirect.com/science/article/pii/S2666352X24000104#:~:text=Hydrogen%2Dpowered%20trains%20generate%20zero,solar%2C%20or%20wind%20power%20plants. 

6. https://www.lhyfe-heroes.com/about-hydrogen/what-is-a-hydrogen-train-the-future-of-sustainable-rail-transport 

7. https://en.wikipedia.org/wiki/Alstom 

8. https://en.wikipedia.org/wiki/Akasol 

9. https://www.doubtnut.com/pcmb-questions/27851 

10. https://www.sciencedirect.com/topics/engineering/regenerative-braking#:~:text=Regenerative%20braking%20is%20a%20unique,to%20a%20standstill%20while%20braking.