Fuel Cell Rail Technology Review: A Tool for an Autonomous Rail Electrifying Strategy

Abstract

Rail (passenger and freight) industry has been under pressure to tackle climate change, local and noise emissions. The current available powertrain technologies to reach the reduced greenhouse (GHG) and zero local emissions demands are electric (fed from the power grid), battery and fuel cell. However, the associated infrastructure costs (electrical equipments and the required overhead catenary infrastructure) have limited the electric option to heavy loaded corridors. Battery electric powered rail vehicles could be another potential option, but their system recharging requirements might significantly limit the system’s availability, thus, impacting the rail vehicle’s on-the-job performance. The recent breakthrough of fuel cell technology in the heavy duty road industry (mainly transit buses), allied with its operational flexibility and environmental performance has opened the way for this groundbreaking technology in the rail industry. Fuel cells generate electricity onboard, using hydrogen or hydrogen rich hydrocarbon fuels. Electricity is, then, stored in batteries or fed directly into a rail vehicle’s high voltage propulsion system. From an operational perspective, fuel cell powered rail vehicles might replace diesel ones in a one-to-one relationship, with the same range and running times, and a more efficient and less noisy powertrain. Moreover, the on-site refilling station is the only additional infrastructure element required, compared to diesel rail vehicle baselines. In short, fuel cell technology might offer a long term local zero emission alternative, fast refuelling (like diesel), flexibility, with self-electrification, integration with a renewable energy source and a quiet operation. Given their outstanding operational and environmental features, several rail market niches might be addressed by the fuel cell technology: i) light rail and trams in urban environments; ii) commuter and regional trains operating on non electrified tracks; iii) shunt or switch locomotives in rail yards (generally located on central portions of large cities or at the crossroads of major rail distribution hubs); iv) underground mining locomotives, and v) line haul locomotives. Since 2002, there has been an intense activity in the global development of fuel cell technology for the rail industry for both passenger and freight markets. This work is supposed to present, based on the compilation of information from a multitude of acknowledged sources, a review of fuel cell rail technology, followed by an overview of fuel cell rail experiences and feasibility studies, highlighting their main outcomes, as well as fuel cell technology potential to offer lower operational costs (fuel and maintenance) and improved performance for the rail industry.

Analysis of hydrogen-powered propulsion system alternatives for diesel-electric regional trains

“…Molten carbonate fuel cells (MCFCs) are another high-temperature FCs (600-650 • C), offering high output power (up to 3 MW), utilized mainly in stationary power generation systems (US Department of Energy, 2021). Considering the applicability to the railway sector, low-temperature PEMFC fits best to non-permanent demand cycles, and applications like light rail vehicles, commuter and regional trains, shunt/switch and underground mine locomotives, while high-temperature SOFC has been seen as a promising technology for freight or heavy haul locomotives, given their long operation time and steady duty cycles (Barbosa, 2019;Sun et al, 2021).…”

A review of hydrogen technologies and engineering solutions for railway vehicle design and operations

“…Electricity can be produced in an FC by using clean hydrogen generated by renewable energy sources such as solar, wind, hydro or hydrogen-rich hydrocarbon fuels, and it is then fed directly into a rail vehicle propulsion system or stored in batteries [17]. An FC locomotive could be built with the same power capability as a diesel-electric one, but there are significant challenges with on-board fuel storage and/or the need for frequent refilling stations.…”

“…If the storage/refilling problem could be solved, hydrogen FC technology could provide a long-term local zero emissions with fast refuelling techniques (like diesel), flexibility, self-electrification, integration with renewable energy sources, and a low-noise operation. It is pointed out in [17] that a PEMFC, which operates at moderate temperatures (80°C) and is best fitted to non-permanent demand cycles, has been proposed for applications like light rail and trams, commuter and regional trains, shunt/ switch locomotives, and underground mine locomotives. A solid oxide fuel cell (SOFC), on the other hand, has higher efficiency than other types of FCs, but needs to work at a high operating temperature (1,000°C).…”

“…China's first hydrogen FC train was developed in 2010 [38]. A tram powered with a 200 kW PEMFC was developed in China in 2015 [17] and has been in commercial service since 2019, with the maximum speed of 70 km/h. Germany's first hydrogen FC-powered commuter train (Coradia iLint) was successfully operational in 2017 [39].…”

“…It is suggested [102] that in the medium to longer term, hydrogen transport mode could be one of the possible strategies that can significantly alleviate GHG emissions. It is assumed in [17] that diesel engines play a dominant role in rail transport at the global level currently at 70%, followed by 30% being fully electric locomotives. The existing diesel engines, and so a large proportion of current fleets, do not depend on overhead catenary infrastructure.…”