San Bernardino, a city in Southern California, has introduced the first hydrogen-powered passenger train in the United States, marking a significant step towards California’s 2045 carbon neutrality goals.
Named Zemu, short for Zero-Emission Multiple Unit, this $20 million train features a hybrid hydrogen fuel cell and battery system. It can carry 108 passengers along a 9-mile route known as the Arrow Corridor. This area is notorious for its poor air quality, due to heavy traffic, rail yards, and industrial activities. San Bernardino recently received a failing grade from the American Lung Association’s 2024 State of the Air Index, which measures days when ozone and particle pollution exceed safe levels. The Zemu train is expected to attract riders not only for its environmental benefits but also because it operates more quietly than traditional trains.
Kaden Killpack, a commercial project manager at Stadler US, who oversees the San Bernardino County Transit Authority (SBCTA), mentioned to The Guardian that the train will be notably quiet. “All you’re going to hear is a couple of HVAC blowers and cooling fans,” he said.
The hydrogen fuel cells in Zemu combine hydrogen and oxygen to produce electricity, with water vapor as the only byproduct. The train is set to become the first passenger train in North America to meet Federal Railroad Administration (FRA) standards when it begins service in 2025. Zemu has been in development for several years, with SBCTA partnering with Swiss rail manufacturer Stadler Inc. to address local air quality issues and reduce road congestion. “Once you add hydrogen to the vehicle, you achieve zero-emission technology on the same routes used by Union Pacific and NSF,” Killpack added. “That’s what’s really exciting about this.”
The Zemu train could serve as a model for other states aiming to make their transport systems greener. California is actively expanding its hydrogen train program. Caltrans, the state’s transportation department, has commissioned Stadler to produce longer hydrogen-powered trains for the Merced to Sacramento route in the Central Valley. Caltrans has ordered 10 units, with an option to purchase 19 more under an $80 million contract.
Challenges Ahead
High costs remain a major hurdle for the widespread adoption of hydrogen technology in the U.S. transport sector. Bloomberg New Energy Finance (BNEF) reported that only 12% of hydrogen plants have secured binding customer agreements. Most agreements are vague and non-binding, making it risky for developers. Industries that could use hydrogen often face costly retrofitting, making the transition difficult.
“You need to sell at least hundreds of trains to start achieving economies of scale and lower costs,” said Lewis Fulton, the Energy Futures Program director at UC Davis’s Institute for Transportation Studies.
Green hydrogen, produced by electrolyzing water with renewable energy, is significantly more expensive than gray hydrogen, which is made from natural gas without capturing greenhouse gases. Building hydrogen infrastructure is challenging when demand is uncertain.
“No project developer will start producing hydrogen without assured buyers, and no banker will fund such a project without confidence in future sales,” notes BNEF analyst Martin Tengler.
“It’s no different from other large-scale energy developments. Natural gas pipelines weren’t built without customers,” says Laura Luce, CEO of Hy Stor Energy. Her company has secured a letter of intent to supply hydrogen to an iron mill that Sweden’s SSAB SA plans to build in Mississippi.
Even in Europe, which is focused on renewables, cost issues are significant. “If half of our projects come to fruition, we’ll be pleased. If a quarter do, we’ll be satisfied,” said Andy Marsh, CEO of Plug Power Inc. (NASDAQ
), referring to the company’s ongoing European green hydrogen projects. Marsh noted that EU member states are still integrating hydrogen plans into regulations, which is delaying private investment.