Hyundai Rotem’s hydrogen fuel cell tram was selected as one of the “R&D Top 10 Achievements” by the Ministry of Trade, Industry and Energy through a public online vote at the “Industrial-TECH Fair 2024.” The Industrial-TECH Fair 2024, Korea’s largest government R&D achievement exhibition, was held from November 27 to 29, 2024 at COEX in Gangnam-gu, Seoul. Under the theme “Dynamic R&D Driven by the Private Sector and Supported by the Government,” this three-day event was planned to encourage industrial technologists who achieved outstanding results and to explore public-private cooperation strategies to secure an edge in the global technology competition.

At this event, Hyundai Rotem showcased the hydrogen fuel cell tram selected as one of the top 10 breakthrough industrial technologies developed with domestic technology and presented a vision for realizing a hydrogen society by exhibiting a hydrogen society diorama and hydrogen fuel cell models to attendees.

Future Growth Engine in the Decarbonization Era: Hydrogen Energy

Hyundai Rotem has recently completed the development of a hydrogen fuel cell tram based on hydrogen fuel cells, taking significant strides toward entering the hydrogen society. Through the hydrogen fuel cell tram demonstration project organized by the Ministry of Trade, Industry, and Energy in 2024, Hyundai Rotem successfully developed key components, conducted demonstration driving tests, and signed a contract to supply a hydrogen fuel cell tram with 34 trainsets for the Daejeon Metro Line 2. Starting with developing and demonstrating the hydrogen fuel cell tram, Hyundai Rotem is also focusing its research and development efforts on mapping out the future roadmap for hydrogen mobility, including hydrogen locomotives and hydrogen high-speed trains. This commitment is driven by a firm belief that hydrogen energy is the only solution to ensuring a sustainable world and the future of the railway industry.

Global market research firm McKinsey & Company identified hydrogen energy as a key solution for achieving global climate goals in its 2022 report, “Unlocking Hydrogen’s Power for Long-Haul Freight Transport.” The report projected that hydrogen could replace fossil fuels across all industrial sectors. The transition to a hydrogen society, where hydrogen produces electrical energy, is already underway. Major advanced nations are investing substantial time and resources to enhance the completeness of every stage of the hydrogen value chain. Another report by McKinsey, “Road Map to a US Hydrogen Economy,” predicts that by around 2050, hydrogen will account for 18% of the world’s energy demand. The transition to a hydrogen society is expected to reduce annual greenhouse gas emissions by 6 billion tons. Additionally, it forecasts the emergence of a new $2.5 trillion hydrogen market and the creation of about 30 million new jobs worldwide. This indicates that the shift to a hydrogen society will not only enhance environmental sustainability but also serve as a new growth engine from an economic perspective.

In Korea, some companies anticipated the potential of hydrogen as a future energy source and acted swiftly. Hyundai Motor Company began research and development on hydrogen energy 30 years ago, and these efforts have since expanded to the Hyundai Motor Group. Hyundai Motor recently extended its hydrogen fuel cell brand, “HTWO,” to encompass its hydrogen value chain business. The company aims to combine unit solutions (grids) tailored to various environmental characteristics and customer needs at every stage, from hydrogen production to storage, transportation and utilization to offer optimized, customized packages. Hyundai Rotem also shares Hyundai Motor Group’s HTWO vision, taking on a key role in the transition to future energy by covering every stage from hydrogen production to utilization. Before officially introducing hydrogen trains, Hyundai Rotem has secured technologies essential for establishing hydrogen infrastructure, including the Hy-Green 300 biogas-based hydrogen extractor, hydrogen charging stations, and hydrogen shipping centers.

Why Hyundai Rotem Took the Lead in Developing the Hydrogen Fuel Cell Tram

After successfully developing the hydrogen fuel cell tram concept car in 2021, Hyundai Rotem officially began developing a commercialized model of the hydrogen fuel cell tram by participating in the “Development and Verification of Core Fuel Cell Technologies for Export-Oriented Hydrogen Fuel Cell Trams” project, led by the Ministry of Trade, Industry, and Energy, in July 2021. This project, which Hyundai Rotem oversaw and involved participation from the Korea Automotive Technology Institute, Korea Railroad Research Institute, and Ulsan Technopark, was carried out over approximately three years. Through this project, Hyundai Rotem secured competitive advantages in the domestic and international hydrogen railway vehicle markets and developed the capabilities to respond to commercialization opportunities.

The tram, a mean of transportation that has existed domestically and internationally since the 1880s, began to fade from use after the rise of automobiles in the late 1960s. However, starting in the 1980s, it experienced a revival, particularly in European cities, and has since become a core urban public transportation option. *In Korea, 22 cities plan to introduce trams (35 routes, 456.33 km in total length). Daejeon, Ulsan and Jeju have decided to adopt hydrogen fuel cell trams and the hydrogen fuel cell tram is scheduled to commence commercial operations on Daejeon Metro Line 2 in 2028, marking a first for the country. The decision to introduce hydrogen fuel cell trams on Daejeon Metro Line 2 serves as evidence of the economic feasibility and safety of the hydrogen fuel cell tram system and the technological superiority of Hyundai Rotem’s hydrogen mobility solutions. This is expected to ripple effect on other municipalities considering adopting tram.

^{* sources : Monthly H2 Economy, “Hydrogen Trams Emerging as Eco-Friendly Urban Public Transport,” October 21, 2024.} 

Features of the Hydrogen Fuel Cell Tram Set to Operate in Daejeon and Ulsan

The hydrogen fuel cell tram developed by Hyundai Rotem can be configured as either a 5-module or 3-module tram. The 5-module tram has been fully developed through the recent demonstration project, and its design is currently being adapted for Daejeon Metro Line 2. The vehicle’s total length is 35m, and the height is 3.7m (4.0m for the extended version), with a maximum design speed of 70 km/h. The minimum radius of curvature is 25m, and it can operate on tracks with a gradient of 60 per mile slope. It simply means the vehicle can climb or descend a maximum slope of 6%.

The tram features an optimal design with various mechanical components mounted on the roof to suit its low-floor structure while ensuring a lightweight axle load. Additionally, it incorporates Korea’s unique rotary bogie system, enabling superior performance in dense urban environments. The rotary bogie enhances curve negotiation and reduces rail contact angles, effectively minimizing noise.

Safety measures for hydrogen refueling have been meticulously addressed. The hydrogen refueling safety device monitors the state of the hydrogen tank, including pressure and temperature, via infrared communication between the hydrogen refueling equipment and the vehicle’s hydrogen receptacle (charging connector). Additionally, a hydrogen overcharge prevention device, which detects pressure differences between the inside of the hydrogen tank and the hydrogen supply line, enhances safety by preventing overcharging.

The design, which won the iF Design Award in 2023, reflects a philosophy prioritizing purpose, functionality, and safety over mere styling, encapsulating the vision of future hydrogen mobility. The wide front window ensures a clear field of view for the driver, while the signature lighting symbolizes the sustainable and expandable future potential of hydrogen with a dynamic and high-tech aesthetic. The front cover is also designed to minimize physical injuries in a pedestrian accident.

The interior space prioritizes the convenience and safety of both passengers and the driver. The cabin layout is designed considering passenger boarding, alighting, and movement, while surface-emitting lights are installed across the entire ceiling to create a bright cabin atmosphere. The cabin also includes a multi-purpose area for storing various luggage sizes, and the edges of interior facilities are rounded to enhance passenger safety. Additionally, the design stands out for its ease of cleaning and disinfection, ensuring convenience in operation and maintenance.

The driver’s cabin minimizes the size of monitors and control switch modules to provide a wide field of view, and front, side and rear cameras are installed to eliminate blind spots. Frequently used functions like the emergency switch are applied as physical buttons to enhance operational efficiency. A luggage tray is also provided for the driver, ensuring additional convenience. Moreover, the driver’s cabin design complies with the railway vehicle driver’s cabin layout (UIC-651) from International Union of Railways.

Hyundai Rotem plans to begin delivering the first hydrogen fuel cell tram trainset in the second half of 2026 and complete producing 34 five-module trainsets, along with signal and inspection systems, for Daejeon Metro Line 2 by the first half of 2028. Daejeon and Hyundai Rotem signed the final contract on July 25, 2024, and held a public report event on August 26 to mark the start of hydrogen fuel cell tram production. Daejeon Metro Line 2, scheduled to officially open at the end of 2028, will be 38.8 km in total length, covering both branch and circular lines. It will feature 45 stations and one train depot, connecting all five districts of Daejeon. This line will become the world’s longest single tram route and be constructed entirely as a catenary-free system. Catenary-free trams do not require overhead wires along the tracks, offering advantages regarding environmental impact and urban aesthetics.

Daejeon held a groundbreaking ceremony for Metro Line 2 construction on December 11, 2024 and began full-scale construction of Line 2 of the Daejeon Metro tram system. During the ceremony, Hyundai Rotem unveiled the preliminary design of the hydrogen fuel cell tram for the first time and a public preference survey was conducted. Daejeon plans to finalize the tram’s design in February 2025 after expert consultations, a second public preference survey, and a public design review.

Meanwhile, Ulsan completed over 5,000 km of demonstration runs with the hydrogen fuel cell tram developed by Hyundai Rotem between October 2023 and March 2024. From April 11 to May 10, 2024, Ulsan conducted comprehensive performance verification, test-line operations and promotional test-drive experiences as part of the demonstration project. About 3,000 participants, including Ulsan citizens, business representatives, academics and local community members, attended the ride-along event to experience this new eco-friendly transportation firsthand.

Ulsan plans to initially deploy the hydrogen fuel cell tram on the 4.6 km route between Taehwagang Station and Ulsan Port Station in Ulsan’s Nam-gu district, scheduled for official opening in 2027. This project was planned to support the city’s bid for the International Garden Show and boost tourism at Jangsaengpo Whale Culture Village in Nam-gu. After the opening, an additional 1.9 km section between Ulsan Port Station and Jangsaengpo Whale Special District will be installed. Subsequently, hydrogen fuel cell trams are also expected to be introduced on Ulsan Metro Line 1, targeted for opening in 2029. Ulsan Metro Line 1 will connect about 11 km stretch (15 stations) from Taehwagang Station in Nam-gu to Gonguptap Rotary, Ulsan University and Sinbok Junction. This project is anticipated to significantly alleviate transportation inconveniences in Ulsan, which remains the only metropolitan city in South Korea without a subway (metropolitan rail transit) system.

Hyundai Rotem’s Hydrogen Mobility Roadmap: From Hydrogen Fuel Cell Trams to Hydrogen-Powered High-Speed Trains

After successfully commercializing the hydrogen fuel cell tram, Hyundai Rotem is spearheading efforts to develop hydrogen mobility solutions through its Rail Solutions Research Institute. These include hydrogen commuters (self-powered passenger or freight rail vehicles) based on the propulsion system of hydrogen fuel cell trams and hydrogen fuel cell locomotives and hydrogen high-speed trains that replace outdated diesel locomotives with high-capacity hydrogen fuel cell systems.

Hyundai Rotem is also considering overseas markets for its hydrogen railway vehicles. A model with the same power output as the one used in BuTX but configured as a 7-car trainset—adding one extra car—has been proposed to the Saudi Arabian Railways (SAR). Unlike BuTX, which operates in underground tunnels with limited passenger capacity due to high air resistance, extra cars can be added as the Saudi Arabian route operates above ground.

Additionally, Hyundai Rotem is developing a hydrogen fuel cell trailer (FC-REEV) designed to extend the driving range of existing electric buses, which connects a hydrogen fuel cell power unit that generates over 60 kW to electric buses like a trailer. As of November 2024, the continuous power output and operational efficiency of the trailer system have been evaluated. Durability tests and over 5,000 km of demonstration driving are underway in Changwon City. The verification of durability performance is expected to be completed by the first half of 2025.

The transition to a fully hydrogen-based society is a transformative process that fundamentally reshapes modern society, which has grown dependent on fossil fuels. As such, it requires a meticulous and comprehensive approach with a long-term vision for the distant future. Since initiating its exploration of the hydrogen infrastructure business in 2018, Hyundai Rotem has achieved the world’s first commercial hydrogen fuel cell tram in just over six years. As part of its carbon-neutral strategy to achieve zero carbon emissions by 2050, Hyundai Rotem is concentrating on developing large-scale hydrogen mobility solutions and establishing a robust hydrogen supply network. The company aims to lead the railway industry into the carbon-neutral era.