A recent study in Germany has found that battery electric trains were 35% less expensive to buy and operate over trains that ran on hydrogen fuel cells powered by green hydrogen. The study examined the cost over a 30-year life cycle and it concluded that the trains’ fuel cell version would be even more expensive than the diesel variant that they would replace, owing to the cost of the fuel cells and the surrounding infrastructure. This includes producing the hydrogen, setting up the refueling stations and the upfront cost of purchasing the fuel cells.

Fig. 1: Alstom’s battery electric regional train that runs in Germany | Image: Alstom

The German state of Baden-Württemberg has found in a separate study that for inter-city connections, hydrogen fuel cell trains would cost 80% more over 30 years than battery-powered hybrids.

These studies point to the growing case around the world for using electric trains. Apart from Germany, there are battery electric trains running in the US and Australia, while a high speed line is planned from Los Angeles to Las Vegas that will run entirely on solar power. Initially met with a lot of skepticism, battery electric trains are proving to be viable for both passenger and freight transportation because of their low running costs.

Fig. 2: The Wabtec battery electric freight locomotive in service in the US | Image: The Guardian

Incidentally, the world’s first all-electric freight train service was started in Pittsburgh, Pennsylvania (US) in September 2021, and is the first in line in an industry that the IEA says only hauls around 7% of all freight globally.

Opportunity for India

This points to an excellent opportunity for Indian Railways. India achieved the distinction of being a fully-electrified rail network in March 2023 when two new rail lines in Meghalaya were brought online. The country has also placed a gigantic order for state-of-the-art electric locomotives from Siemens, which will supply 1,200, 9000 horsepower locomotives at a cost of around Rs. 26,000 crores.

Fig. 3: Siemens will supply India with 1200 electric locomotives as part of a giant new order | Image: Siemens

Put together, the Indian rail network now covers more than 108,000 km of track and the Siemens order comes at a time when the network plans to become a net zero carbon emitter by 2030. The government also has plans to increase the share of freight carried by the railways from 27% to 45% by 2030. This is to offset the emissions from the diesel truck-heavy road transport sector, which alone accounts for 14% of India’s CO2 emissions. However, most of the power from India’s electric locomotives still comes from fossil fuels.

Thus, the potential for emissions reduction is enormous. The Railways already has an internal target of sourcing 20GW of solar power by 2030. This target is supported by a study from 2021 that says that it can source up to 28% of solar power from its own captive capacity, which would enable it to run 1 in 4 trains through self-generated power. It must be noted that for locomotives that are diesel-electric hybrids, converting them to run on electric power from renewables alone would require the addition of a battery car which would be connected to the existing drivetrain.

Benefits for air quality

Switching to trains run on renewables alone will benefit the local air quality as well. India loses around 2 million people a year to high air pollutant concentrations, and while an exact number attributable to diesel locomotives is not available, it could be significant. A report from the US, for instance, calculated that it loses around 1,000 lives prematurely every year because of the emissions from its diesel locomotives.

Fig. 4: France has banned short haul flights that last for less than 2.5 hours, in favour of train journeys instead | Image: BBC

The air quality benefits would be even more pronounced if high speed rail corridors are built along the major routes, as it would alleviate the emissions from the flights carrying the same passengers. This is similar to the steps taken in France and Germany, that have either banned or are considering restricting short-haul flights to clamp down on emissions.

The potential for battery electric trains in India therefore must be fully utilised. The form factor of trains makes them good candidates to store large battery packs, and feasibility studies indicate that a switch from diesel-electric locomotives is certainly possible.