Traction Batteries: Powering the Path from Diesel to Electric Rail

By Andreas Z’Graggen, Head of Energy Storage Systems, ABB Traction Division

Rail operators are racing to decarbonise, and traction batteries are emerging as a vital bridge between diesel-powered legacy fleets and the fully electric systems of tomorrow.

As the rail industry pushes to achieve climate goals and meet an ever-growing regulatory burden, the transition away from diesel is a fast-approaching reality in the rail sector’s decarbonisation journey.

The Challenge

There is a key short-term challenge – whilst full electrification is the ideal model, it is not always immediately feasible, but that’s where traction batteries come in, offering the only flexible and scalable solution to reach environmental objectives. Beyond cutting carbon emissions, they also enhance passenger experience and deliver instant engineering value for rail operators.

As rail operators seek sustainable alternatives, the complexities of transitioning away from diesel must be acknowledged. Diesel engines, while entrenched, are no longer compatible with sustainability mandates or emissions targets as they are significant sources of air pollution. Many see fully electrified rail networks as the only alternative; however, they are not a one-size- fits-all solution and are costly and time-consuming to implement. Not only that, but electrified rail can also be geographically impractical when regions lack continuous catenary infrastructure or face budgetary constraints.

Advantages of Traction Batteries

The limitations of diesel and the delays in full electrification mean that an opportunity is emerging for traction batteries to offer a stepping stone to full electrification, especially in semi-electrified railway lines. Traction batteries bring unmatched flexibility, reduced emissions and compatibility with partial electrification. Whether powering hybrid configurations or enabling fully battery-electric operation, they offer a long-term solution that supports today’s needs and existing infrastructure while future-proofing tomorrow’s rail networks. This flexibility of deployment outweighs that of other decarbonisation measures, such as using alternative fuel sources.