South Korea is moving swiftly toward commercializing zero-emission hydrogen trains capable of making a round trip between Seoul and Busan on a single charge.
As environmental regulations tighten worldwide, the search for cleaner modes of transport has intensified. The rail sector, long overshadowed by aviation for long-distance travel, is looking to hydrogen technology and higher speeds as its path forward.
Conventional diesel trains are among the leading sources of carbon emissions and fine dust in the rail industry. Newly introduced diesel rolling stock must now comply with stricter air pollutant emission standards under the government’s comprehensive fine-dust management plan.
It is against this backdrop that hydrogen trains have drawn global attention, including in South Korea.
A hydrogen train generates electricity by feeding hydrogen stored in onboard tanks into a fuel cell, then uses that electricity to drive its motors. Because it requires no external power supply through overhead lines, the technology can dramatically improve rail access in non-electrified areas where building conventional electric rail infrastructure is difficult.
Hydrogen trains emit nothing but water, producing less carbon dioxide than electric vehicles. While conventional diesel trains emit 19 kg of CO₂ per kilometer, hydrogen trains emit just 9.1 kg — roughly half. The absence of overhead lines, substations and other power-supply equipment also reduces construction and maintenance costs.
Ryu Jun-hyeong, a researcher at the Korea Railroad Research Institute, said:
Electric railways need overhead lines, substations and power-feed systems, but hydrogen trains generate and use their own electricity onboard through hydrogen storage tanks, fuel cells, batteries and an electric propulsion system,
“They can operate without any external power supply, improving access on non-electrified lines, and their energy efficiency is more than twice that of diesel trains.”
The global hydrogen train market is forecast to grow at an average annual rate of more than 25 percent, reaching $26.4 billion by 2035, with countries around the world racing to develop and commercialize the technology.
France’s Alstom launched the world’s first commercial hydrogen train service in Germany in 2018. Germany has committed 9 billion euros ($10.2 billion) through its national hydrogen strategy to build out a hydrogen ecosystem that includes rail infrastructure. Scotland is pursuing a roadmap to phase out diesel trains by 2030. China opened a hydrogen tram line in late 2019, and Japan operates hydrogen trains using an electric multiple-unit design. The United States is also accelerating commercialization — California launched its first commercial hydrogen passenger train service in September last year.
South Korea has now joined the effort, launching a research and development project to build hydrogen infrastructure on existing operating lines and conduct trial runs toward full commercialization.
The project will receive a total of 32.1 billion won through 2027, with Korail and the Korea Railroad Research Institute serving as lead agencies.
The project will also build hydrogen train infrastructure — including hydrogen refueling stations and vehicle maintenance facilities — on currently operating non-electrified lines, and will verify the performance and suitability of the facilities by running hydrogen electric multiple units alongside existing services.
To support a smooth rollout, the project will establish technical standards and operating and management regulations for hydrogen trains, while also pursuing regulatory reforms and the removal of unreasonable restrictions.
Trial runs are planned on the Gyooe Line and the Gyeongwon Line before commercial service begins in 2028. Hydrogen tram construction is also underway in Daejeon and Ulsan.
The demonstration vehicle is being designed to deliver 1.2 MW of output, reach a top operating speed of 150 km/h — matching the ITX intercity express — with a design speed of 165 km/h, cover more than 600 km on a single charge, and run as a two-car set. The train is to be built in 2027 and will undergo safety certification including rolling stock type approval before entering service on the demonstration line, where hydrogen refueling stations, maintenance facilities, technical standards and operating regulations will also be verified.
Candidate routes for the demonstration include the Gyeongwon Line between Yeoncheon and Baengmagoji Station (21 km) and the Gyooe Line between Daegok and Uijeongbu Station (30.3 km). The Ministry of Land, Infrastructure and Transport has proposed deploying a two-car hydrogen electric multiple unit for about a year of test runs covering more than 70,000 km from 2027, with three additional sets to be introduced after the demonstration phase to replace aging diesel trains. A multipurpose hydrogen refueling station serving hydrogen trains, hydrogen buses and passenger cars is also planned at Yeoncheon Station, with three dispensers rated at 160 kg per hour and a maximum daily supply capacity of 1,300 kg.
Ryu said,
Regulations and laws are already in place for hydrogen vehicles, but we still need to build the institutional foundation for a hydrogen mobility industry ecosystem,
“As hydrogen fuel cell technology advances further, we expect it will eventually be applicable to high-speed rail as well.”
The Korea Railroad Research Institute is also developing a liquid hydrogen train with a range more than twice that of conventional hydrogen trains.
The goal is a self-powered hydrogen electric locomotive capable of carrying passengers and freight on non-electrified and mixed-use lines, replacing aging diesel locomotives that have reached the end of their service life.
Liquid hydrogen is hydrogen cooled to below minus 253 degrees Celsius, a state in which it can be stored and transported more safely than high-pressure gaseous hydrogen because the pressure involved is far lower. The institute chose liquid hydrogen for long-distance locomotive applications because of its higher storage density and transport efficiency compared with gaseous hydrogen.
The liquid hydrogen train under development targets a 1.6-fold improvement in range and a 20 percent reduction in refueling time compared with foreign gaseous hydrogen trains operating at 700 bar — a pressure equivalent to 100,000 newtons of force per square meter.
The institute has developed an onboard liquid hydrogen supply system, a core technology for liquid hydrogen rail vehicles. The system integrates multi-stage controls for pressure, flow rate and temperature into a single compact control unit, reducing volume by 10 percent and weight by 5 percent compared with the previous modular approach. The result is a range improvement of more than twice that of existing hydrogen trains on a single charge.
The system is designed to stably power four 95 kW fuel cells — 380 kW in total — and has reached a level of maturity suitable for actual railway propulsion applications.
The onboard liquid hydrogen supply system is ready for immediate installation on trains and is expected to accelerate the conversion of aging diesel trains to liquid hydrogen propulsion.
Kim Gil-dong, a senior researcher at the Korea Railroad Research Institute, said:
We plan to verify the performance of this core technology through a range of tests,
“We also plan to apply the propulsion system to existing hydrogen trams and extend the work into liquid hydrogen-based demonstration research.”
READ the latest news shaping the hydrogen market at Hydrogen Central
South Korea bets on hydrogen trains that can run 600 km on a single charge, source