Integrated Travel Research and Development


Comparative Analysis of Hydrogen Fuel Cell and Battery
Hybrid Retrofitting for Diesel Locomotives: Design,
Performance, and Economic Feasibility


Shivangi Sharma
M.S. Mechanical Engineering, Arizona State University

 

This research focuses on the pressing need to decarbonize diesel locomotives by examining the viability and performance of retrofitting them with hybrid systems that combine hydrogen fuel cells and batteries. Drawing from dozens of peer-reviewed articles, technical reports, and industry analyses, we investigated the design requirements for these systems, including technologies for battery and hydrogen storage, regenerative braking methods, and cost estimates. The results reveal important trade-offs between fuel cell and battery technologies, limitations related to thermal and spatial integration, and the best configurations for routes such as Calgary to Edmonton.


We determined that a hybrid system using modular battery packs and PEM fuel cells provides the optimal balance of emission reduction, operational efficiency, and ease of retrofitting conventional diesel electric locomotives. The goals are to create efficient, safe, and modular battery packs that can work alongside hydrogen fuel cells for both propulsion and regenerative braking. These battery packs need to effectively store energy to capture braking energy from frequent stops, especially on routes with up to 20 stops over 324 km, thereby improving overall efficiency. Furthermore, the design should prioritize modularity for easy maintenance and scalability based on the train configuration.


Key limitations include the maximum train length of about 200 meters, the space available on each locomotive (approximately 22 meters), weight restrictions, challenges in thermal management due to high power density, energy density needs for long-distance travel, and overall system costs. The decision to use one or two locomotives for housing hydrogen tanks, fuel cells, and batteries is  significantly influenced by these constraints.


An analysis of hydrogen fuel cell systems in locomotives indicates that models like the P42, Siemens Charger, and Alstom ALP45DP are promising candidates for retrofitting, as they possess adequate structural capacity and have been modified for hybrid systems in North America. Existing hydrogen powered trains, such as CPKC freight locomotives and the Stadler FLIRT units in California, offer valuable lessons regarding system integration, storage, and operational efficiency