In June this year, the certification process for the first Polish shunting locomotive powered by hydrogen cells was completed. Bydgoszcz Pesa's SM42-6Dn is a four-axis Bo-Bo shunting locomotive in which hydrogen cells with a total power of 170kW power four 180kW asynchronous traction motors, allowing the locomotive to reach a speed of up to 90 km/h. The product of a zero-emission hydrogen-powered railway pilot project, implemented by Pesa in Bydgoszcz since 2019, will soon be put into service. The extensive modernization and rebuilding of a SM42 diesel locomotive bring a revolution regarding the reduction of emissions in rail transport a step closer, and homologation tests completed in June, under the auspices of the Office of Rail Transport, on a test track in Zmigród herald an oncoming change in the rail transport area.
SM42-6Dn
The SM42-6Dn shunting locomotive is a zero-emission, 70-tonne locomotive, designed for shunting works and pulling light goods trains, especially in the area of intermodal terminals and the so-called "green ports." The first such locomotives will be operated by RCP Orlen – Koltrans.
source: www.pesa.pl/produkty/lokomotywy/sm42-6dn-hydrogen/#koltrans
The SM42 locomotive frame has an embedded three-box body with a centrally located newly designed two-way cabin, on one side of which there are hydrogen cells with a total power of 170kW, a hydrogen cooling system and one of two hydrogen tanks. On the opposite side of the cabin there is a braking system cabinet, a second hydrogen tank, a choke and an inverter used to drive electric traction motors. The total capacity of Class III hydrogen tanks is 175 kg H2, at a storage pressure of 350 MPa. Theoretically, in the case of continuous operation using the full power of hydrogen cells, reserve fuel, for fuel consumption not exceeding 0.08 kg/kWh according to the manufacturer's declaration, is sufficient for over 12 hours of continuous operation under full load. In addition, the locomotive is equipped with an obstacle detection and collision detection system as well as a radio control system with autonomous driving function so that the driver can single-handedly control the vehicle when sorting rolling stock into trains.
Advancements in the implementation of hydrogen drives in various areas of transport poses the question about zero-emission sources of such solutions.
Where does hydrogen for transportation come from?
The two most popular sources of hydrogen for transportation are: steam reforming of natural gas and water electrolysis. Efforts are also made to obtain hydrogen for propelling vehicles from gasified biomass, but reforming and electrolysis are still dominant in comparison to other technologies as regards mass production of hydrogen.
When considering the zero-emission nature of hydrogen vehicles, it should be borne in mind that both steam reforming, in which steam involved in the steam reforming reaction must be heated to a temperature of 750 to 950°C, and water electrolysis require substantial amounts of power. In addition, it is estimated that in the case of classical steam reforming, up to 12 kg of CO2 is formed (only from the reaction of methane decomposition into hydrogen, carbon monoxide and carbon dioxide alone, without taking into account the emissions related to the production of electricity) per 1 kg of hydrogen, called "grey hydrogen."
In the transitional phase of obtaining truly emission-free "green hydrogen," steam reforming combined with CO2 capture technologies is used, which reduces CO2 emissions by up to 95%, as a result of which the so-called "blue hydrogen" is produced.
The striving of, among others, the European Union for zero-emission, as part of which the so-called "green hydrogen" will be produced by water electrolysis using electricity from renewable energy sources, allows us to hope for truly emission-free transport, including the rail. Unfortunately, in our country, we are confronted with another problem, namely the so-called energy mix.
According to data for May 2023, published at Rynekelektryczny.pl, 71.49% of electric power in Poland came from power plants powered by fossil fuels or biomass combustion, while the remaining 28.51% came from wind, hydro and solar power plants. Considering that between 2021 and 2022 the share of RES in Poland's energy mix increased by 2%, we still have a long way to go before we reach zero-emissions, in the context of the entire hydrogen energy chain and, in the case of SM42-6Dn, on Polish railway sidings.
To sum up, it is extremely exciting that locomotives which will be a real alternative to mazut- or diesel-powered locomotives are built in Poland. It is also optimistic that Bydgoszcz Pesa plans to launch a prototype of a bi-articulated passenger train with electric and hydrogen propulsion for passenger transport by 2026 and continue to blaze a trail in rail transport.
Undoubtedly, this is a right and very innovative path in the railway engineering which is worth following, but for the full implementation of zero-emission rail transport we need to fundamentally change the structure of the energy mix, which, despite announced investments in small modular reactors, somewhat controversial due to the waste in the form of spent fuel they produce, will probably take many years or even decades in Poland. However, transport solutions, including rail, using hydrogen as an energy source in an increasingly better and more efficient way, may be still prepared for the time when hydrogen technologies will actually be zero-emission. Before we arrive at the green-hydrogen-on-the-railway station, it is worth observing and keeping our fingers crossed for other projects similar to the SM42-6Dn from Pesa.
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