In the quest to greenify the transport sector, alternative fuels have claimed a place on the rail scene. RailFreight.com had a chat with Stefan Bernsdorf, sales manager for alternative traction solutions at Stadler, about the pros and cons of hydrogen as a fuel for rail freight. Its viability depends on many factors.
From an environmental perspective, hydrogen is a promising alternative fuel, especially when the origin of the hydrogen is fossil-free. When hydrogen energy is converted into traction with a fuel cell, it turns hydrogen and air into heat, water and electricity with no harmful emissions. The alternative to a fuel cell, the combustion engine, would still emit a small amount of the harmful substance NOx, but no carbon compounds.
Its carbon-free nature is hydrogen’s greatest advantage – making it a logical choice for organisations looking to reduce their carbon footprint. But is it viable for the rail freight sector? “That depends”, explains Stefan Bernsdorf. “Hydrogen is particularly attractive for non-electrified lines where overhead electrification is not feasible. It can help achieve a longer range than only battery-powered solutions, making it a viable option for routes where electrification is not possible.” Hydrogen can be used alongside an on-board battery, where a fuel cell acts as a range extender on a hybrid vehicle.
Vehicle range with hydrogen can vary by a factor of five
In principle, hydrogen can match the tractive performance of fuels such as diesel and HVO – but comes with a major drawback: its energy density is much lower. “This is just a hard rule of physics”, says Bernsdorf. “Diesel and HVO carry more energy relative to the volume.” This means that to cover the same distance, a hydrogen-powered train requires significantly more storage space. For freight trains that require a lot of energy, this is a major hurdle.
One of hydrogen’s advantages is that it potentially offers a larger range than battery-only solutions. But its range can, like with other fuels, vary considerably: “The range of hydrogen–powered trains depends on loading, the track profile, the number of stops and starts, among other things. It can also depend on the mood of the driver, and factors such as how efficiently they brake. The weather also has an impact on the energy required for a particular route”, says Bernsdorf. The range of a vehicle using hydrogen can differ by a factor of five, from the best to the worst case scenario.
The supply chain as a financial game changer
“When considering new operations, you need predictability for your business case. The prices of new fuels, like hydrogen, are more volatile than fossil fuel prices”, the Stadler sales manager for alternative traction solutions continues. Diesel has relatively stable pricing. “New fuels, including hydrogen, do not come with an established stable supply chain. A nucleus for a growing supply-and-demand ecosystem could be what is needed to establish supply chains and large scale production to secure economies of scale. We’ll see what the future brings.”
Stadler recognises that supply chain conditions are important. “With hydrogen’s lower energy density, a big part of the fuel cost is transport – you pay a lot for tanks and containers to carry the energy around”, says Bernsdorf. “Stadler is aware of some projects where hydrogen is close to the operator, improving the economic picture.”
Not the most obvious choice for freight
Hydrogen for freight: is it a yes, or a no? “Technically possible, but typically not the first option for consideration”, Bernsdorf concludes. “You need to look at the location, the environment, the weight, the loading, among other factors. Solutions can be wide-ranging. Hydrogen is an option to extend the range of a battery vehicle. We don’t have catenaries; so, what next? Then hydrogen might be an option.”
The high power requirements of freight push towards high energy density (liquid) fuels. “HVO is an intuitive solution to decarbonise rail freight on non-electrified lines”, says Bernsdorf. “Especially when combined with traction batteries to recuperate braking energy and increase efficiency. For lighter vehicles like short-distance commuter trains, battery or hydrogen is an ideal solution, and when feasible, battery-only tends to be the first choice. It is simple, cheaper, and more efficient, but not possible everywhere.”