It is known that transport is one of the major contributors to global climate change, responsible for one quarter of global energy related greenhouse gas (GHG) emissions and one sixth of total emissions, in conjunction with the fastest growing emissions sector.

After COP26 convention, countries have agreed and reinforced the need to reduce global carbon emissions in order to keep limiting global warming to 1.5C above pre-industrial levels.

In this way, this article proposes to evaluate the hydrogen trains technology, analyzing if it could be a good option to reduce freight transport emissions.

Hydrogen Trains

The hydrogen fuel cells have been used by the rail industry as a strategy in the way to reducing dependence on fossil fuels and transit to net zero emissions, once it is a clean energy source that only produce water as a residue. In hydrogen trains, the energy produced in hydrogen fuel cells is made by transforming hydrogen stored in an on-board cylinder and temporarily storing in a special battery, which supplies energy to the train.

The knowledge of hydrogen energy has over 30 years. In the past, there have been peaks of interest in hydrogen, but it hasn’t succeeded so far. Currently, technological developments and the urgency to reduce GHG emissions have triggered again the interest in this technology as it is now becoming more economically viable.

In the last years, many nations have committed to developing strategies and have taken actions to improve the hydrogen ecosystem, in order to scale and reduce the technology cost, which includes the gas production and the vehicles industry. In the US. , hydrogen fuel is included in President Joe Biden’s plans to cut emissions in half by 2030. Furthermore, the European Union set hydrogen as a key priority to achieve the European Green Deal and foresees its participation in Europe’s energy matrix which will grow from the current less than 2% to 13-14% by 2050.

Major rail companies also are investing in hydrogen trains. In 2018, Alstom started a pilot operation of Coradia iLint,… with a hydrogen train that serves passengers between Weser and Elbe, in Germany. It is expected that in 2022 it will be a regular service and that hydrogen trains will begin replacing the existing diesel stock in Lower Saxony. And in 2020, Coradia iLint started the first regular passenger service in Austria. Furthermore, Alstom has also signed an agreement for the development of hydrogen trains to other European countries, as Italy and France. In parallel to that, Stadler secured a contract from the San Bernardino County Transportation Authority in California to deliver the first hydrogen powered trains in the US. They are planning to start service in 2024. Finally, Siemens has firmed a testing operation in Bavaria, beginning in 2023.

Regarding these hydrogen train pilots, mention should be made that the trains under development were projects adapted from trains firstly designed for diesel or electric. It means that once the technology evolves the trains can be more optimized to better fit the fuel cells.

Application

With a range up to 1000 km and refueling time of around 15 minutes, all these trains are designed for passenger transport. Until now, it has only been considered for passengers, as cargo transport requires more traction, which for hydrogen fuel cell would take up a lot of space on board, making it economically unfeasible.

The main uses considered viable and sustainable by hydrogen technology enthusiasts are for long routes, with low traffic and where the costs of installing electrical infrastructure are high.

Carbon Footprint

Despite of hydrogen being the simplest and the most abundant element in the universe, on Earth, it is rarely find in its pure state, so it needs to be separated from other elements. In the context of clean energy, it is important to analyze the carbon footprint of the entire process chain, not just the transport itself.

Nowadays, over than 95% hydrogen production comes from fossil fuels. This hydrogen is called as Gray Hydrogen, due to the high level of CO₂ emissions. On the other hand, the Green Hydrogen is produced by electrolysis using renewable energy sources, with emissions close to zero. Between the two extremes, there is the Blue Hydrogen, produced by electrolysis with energy from the grid or even with CO₂ captured. However, renewable and low-carbon hydrogen are not yet cost competitive compared to fossil-based hydrogens.

Figure 1. Comparison of C0₂ emissions and costs of hydrogen process type (Illustrative)

Even with high levels of emission in the most common hydrogen production, the technology is seen by specialist as a good strategy to help leverage the hydrogen industry and enable cost savings of sustainable hydrogen production achievement would be on largescale. And that achieve is beneficial to many industrial sectors that can use hydrogen power.

Sustainable Freight Transport

In conclusion, the hydrogen trains promise to be a good and sustainable option just for a few cases of rail transport. Due to technology specifications, such as power capacity and volume of hydrogen needed onboard, hydrogen trains work best on low-traffic and low frequency rail services and in places that are very expensive to have electrical infrastructure.

In the specific case of freight transport by rail, the hydrogen needed to carry heavy cargos occupies a large amount of space in the wagon, which makes it an inefficient transport. This does not mean that the railway industry should not invest in hydrogen trains or other ecological solutions. Actually, most of rail freight transports are made by diesel trains, and despite being a better ecological solution than road transport (especially for long routes) diesel trains still emit a high volume of carbon and it is important to reduce it promptly.

In this context and considering the actual possibilities and known technologies until now, the freight transport better option in terms of GHG emissions will be for a long time the electric trains.

 

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About the authors
Tamara Barbosa Gaspar is BSc in Civil Engineering and Team Leader at ALG. tbgaspar@alg-global.com
Guilherme Esmanhoto is BSc in Civil Engineering and MBA. Partner at ALG. gesmanhoto@alg-global.com
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