As nations worldwide push for greener transportation, battery-powered trains are emerging as a promising solution for reducing carbon emissions in rail systems. Recent investments and advancements in technology are driving the development of these zero-emission trains, particularly in countries like Japan and the United Kingdom, with the United States also exploring similar innovations.
Japan Leads the Way in Battery Train Technology
In Japan, the introduction of battery-powered trains is making waves in the transport sector. Between 2016 and 2019, Japan Rail converted 18 Dencha trains from diesel power to electric battery, launching the world’s first battery trains for an AC network. These trains draw power from overhead lines through a pantograph, converting AC electricity to charge their batteries. When traveling through non-electrified sections, the pantograph is lowered, allowing the trains to operate solely on battery power.
The benefits of this technology are significant. By eliminating diesel engines, the trains produce no engine noise, vibration, or exhaust emissions. As a result, maintenance costs have also decreased. By 2021, operators JR Kyushu and Hitachi Rail reported a reduction of approximately 2,700 tonnes of carbon emissions since the launch of these battery trains.
The United Kingdom and the United States Embrace Battery Power
Inspired by Japan’s success, several train operators in the United Kingdom are advancing their own battery train projects. In 2024, Hitachi Rail replaced the diesel engine in one of its intercity Class 802 trains with a 700 kW battery. This pilot journey demonstrated the potential of battery technology, with 70 km powered entirely by battery. The chief director for Hitachi Rail’s U.K. and Ireland operations expressed pride in achieving a trial without any failures, stating, “Using our global expertise, Hitachi Rail has created new technology, which means the greenest mode of transport just got greener.”
The goal is to develop a fully battery-powered intercity train with a range of 100 to 150 km. The U.K. is particularly well-suited for this transition, as much of its rail network operates on overhead electric lines. However, achieving full electrification may take decades due to high setup costs. To bridge the gap, GWR is trialing fast-charging battery trains, having recently converted a London Underground train for a five-mile return trip. The project showed promise, with an 80 percent decrease in carbon emissions compared to a diesel train on the same route.
Across the Atlantic, a 2021 study highlighted the potential for significant savings in the U.S. rail freight sector if companies transition to battery power. Startup Voltify is working to encourage this shift, aiming to introduce battery-powered services for freight trains. The company’s co-founder, Daphna Langer, envisions generating up to $10 billion annually if major freight companies adopt their sodium-ion battery technology.
Currently, the six largest freight railroad companies in the U.S., including Union Pacific and CSX, collectively spend over $11 billion a year on diesel. With nearly 140,000 miles of freight railroad track in the U.S. largely un-electrified, the transition to battery power could yield substantial savings.
Voltify is also developing solar-powered microgrids to support this initiative. The company estimates that powering the entire North American rail network would require around 1,400 microgrids. A pilot project with a Class 1 railroad company is scheduled to begin in early 2026, with plans for commercial-scale operations shortly thereafter.
The path to widespread adoption of battery-powered rail travel remains challenging. Yet, the growing number of successful pilot projects and technological advancements signals a future where rail companies can significantly reduce fuel costs while contributing to a decrease in carbon emissions. As various types of batteries are developed to power trains through both overhead lines and tracks, the potential for broader implementation in the coming decades appears promising.
