In the quest to decarbonize the transportation sector, the railway industry is facing a significant challenge: how to electrify vast networks while maintaining operational efficiency and cost-effectiveness. Antonio Gabaldón, a researcher from the Power Systems Group at the Technical University of Cartagena in Spain, has proposed an innovative solution that could revolutionize the way we think about hybrid locomotives and energy storage systems.
Gabaldón’s research, recently published in the journal Applied Sciences, focuses on the integration of supercapacitors and lithium-ion batteries in hybrid locomotives. This approach aims to address the energy demands of both electrified and non-electrified tracks, particularly for freight operations. The study highlights the potential of hybrid units to act as “railway prosumers,” contributing to both storage and generation in electrified areas. “The key is to leverage the advantages of supercapacitors and batteries to manage energy more efficiently,” Gabaldón explains. “By doing so, we can reduce fuel consumption and greenhouse gas emissions, making rail transport more sustainable.”
The research introduces a novel modeling approach using the Differential Transformation Method (DTM) to solve the non-linear ordinary differential equations governing supercapacitor dynamics. This method, combined with a grid search for parameter optimization, has shown high accuracy compared to laboratory trials. The models developed in the study not only simulate storage sizing and energy management but also analyze energy recovery and unit performance, providing a comprehensive framework for evaluating energy storage systems in hybrid railway applications.
One of the most compelling aspects of Gabaldón’s work is its potential to extend the operational lifetime of mid-life conventional locomotives. By refurbishing these units with on-board energy storage devices, railways can maintain their hauling capabilities while capitalizing on regenerative braking. This approach is particularly relevant for low-traffic routes, where full electrification may not be economically feasible. “Refurbishing mid-life conventional locomotives to extend their operational lifetime is an idea already proposed by some manufacturers for diesel-electric units,” Gabaldón notes. “This hybridization is particularly applicable to freight services and serves as a viable alternative during the necessary transition period to meet decarbonization targets for 2030–2050.”
The commercial implications of this research are vast. By enabling hybrid locomotives to act as mobile generation devices, railways can supply power to electric trains or restore service during overhead line equipment (OLE) failures. This not only enhances operational reliability but also opens up new revenue streams for railway operators. Moreover, the ability to recover a significant portion of braking energy—up to 40–50% on routes with gradients of 1.0–1.2%—could serve as a catalyst for shifting freight transport from road to rail, reducing overall emissions and congestion.
Gabaldón’s work represents a significant step forward in the field of energy storage and hybrid railway systems. By providing a detailed and accurate model for supercapacitors and batteries, the research offers a practical framework for validating hybrid locomotive performance in real-world scenarios. This could pave the way for more efficient and sustainable railway operations, benefiting both the environment and the economy.
As the railway sector continues to evolve, the integration of advanced energy storage technologies will play a crucial role in achieving decarbonization goals. Gabaldón’s research, published in Applied Sciences, provides a roadmap for leveraging these technologies to create a more resilient and efficient railway network. The future of rail transport looks brighter with innovations like these, driving us towards a greener and more sustainable future.
