Why Even a Little Hydrogen Power Can Be Made to Work

The excellent work done by Network Rail’s Traction Decarbonisation Network Strategy (TDNS) group has identified the constraints and opportunities of different types of low carbon traction for most of the GB network. This lays out what the ‘best fit’ type of low carbon traction is for a specific section of track, covering the vast majority of Britain’s 15,400 single track kilometres (STKs). Only 15% of track has not yet had their most suitable type of low carbon traction decided; 6% is most suitable for hydrogen traction.

The TDNS treats electrification as the preferred solution for many lines, especially those with higher traffic volumes. For starters it allows for zero carbon emission at point of use, and can be exceptionally clean if the electricity is generated sustainably. However, the fixed electrification infrastructure can be expensive to provide and maintain through its whole life, and for lightly-used lines this might be difficult to justify. 

Alternatives to electrification are diesel, battery and hydrogen, with various hybrid options too (including in combination with fixed electrification). While there are ways of making diesel more efficient and reduce emissions, battery and hydrogen are the only realistic opportunities for a self-powered zero carbon train. 

Hydrogen as a fuel is novel to the railway. An explosive gas, it introduces new risks and needs a careful approach so that the railway and its neighbours remain safe and there is no loss in public confidence. However, knowledge and expertise is limited. The engineering, operational and legal issues that this brings for any one train operator, maintainer or infrastructure manager are significant, potentially even prohibitive. 

While significant these are not insurmountable barriers. Through collaboration with stakeholders, consolidating research, learning and experience, it is possible to drive the market through standardised processes, systems, engineering and operational requirements.

RSSB is already working with industry partners supporting safety analysis of hydrogen trains, mapping the process and dependencies to safely integrate hydrogen trains on the network. Work is underway to assess the legal framework and help stakeholders understand their boundaries of responsibility. The whole operational lifecycle is being considered, including depots and the hydrogen supply chain. All this is done in collaboration with standards bodies, academia and manufacturers, learning and adopting relevant good practice from other sectors (for example automotive) and influencing a global approach to standardisation to achieve wider economies of scale.

Hydrogen trains may be niche, but they are real and being shown to work, so it’s crucial they’re part of the standards debate.