Alstom's green traction solutions: sustainable solutions for non-electrified railways

Battery and hydrogen propulsion technologies are both credible and complementary alternatives to diesel. Each technology has its use case, depending on the operational context and technical requirements. In addition to fulfilling functional requirements, several other factors influence the choice of the appropriate technology, such as operating costs and investment. This is why a total cost of ownership approach, including environmental footprint impact, should be considered when choosing between technologies, including infrastructure availability and vehicle purchase.

Green re-tractioning for existing rolling stock

Alstom’s FlexCare Modernise™ portfolio offers zero direct emission green re-tractioning for existing rolling stock by replacing diesel with hydrogen and battery solutions. For customers looking to reduce their diesel consumption and CO₂ emissions from train operations, we offer low-emission re-tractioning, which consists of upgrading diesel traction with a combination of battery or hydrogen technology.

Benefits of green re-tractioning

The re-tractioning of existing rolling stock enables asset owners to meet new environmental standards, lower energy consumption and reduce emissions. Our customers can capitalise on their existing rolling stock while reducing costs and becoming more sustainable.

Re-tractioning can also be used as an opportunity for a lifetime extension, allowing customers to improve performance and reduce energy consumption and environmental impact while adding 20 years of useful life to an existing train. Starting with a feasibility study on emission reduction, costs, and fleet performance, Alstom would build a prototype/pilot for testing and find the right solutions for the customer’s fleet.

Business cases for battery and hydrogen electric vehicles, as well as operational performances, are more dependent on charging solutions than diesel trains, in addition to being more complex to manage. Building on its rolling stock knowledge and first experiences with these new traction technologies, Alstom can propose a products and services portfolio of charging solutions in partnership with specialised companies.

We are committed to expanding our offer to support the introduction of hydrogen and battery traction according to customers’ needs, such as reducing energy consumption or providing a fast-charging solution.

Battery charging solutions

Over the last 20 years, Alstom has developed a portfolio of electrical infrastructure solutions to facilitate the integration of railway vehicles in their operational environments, such as historical city centres for tramway applications. These solutions include ground-based charging solutions such as APS™ and SRS™ ground level power supply or our advanced reversible power substation Hesop™, overhead lines, charging islands and depot charging.

Alstom's battery charging solution portfolio:

• Considers pantograph or alternatives such as plugs and contact shoes
• Includes dynamic and static solutions, depending on the vehicle equipment with a pantograph, on the charging modality, on the maximum power needed or on the public accessibility around charging areas
• Provides a system approach between the vehicle onboard traction battery and the charging station in order to find the best compromise between the vehicle onboard energy storage, the number of charging stations, their positioning and the maximum power available from the electrical grid.

Hydrogen refuelling solutions

Empowered by its track record of introducing the world’s first hydrogen vehicle fleets for commercial passenger service, Alstom enables a seamless transition from diesel to hydrogen refuelling worldwide together with key partners in the hydrogen sector:

• Applying an optimum system approach between the vehicle onboard hydrogen storage system and the refuelling station to cope with physical phenomena during refuelling operations, such as temperature rises and drops in pressure
• Considering the railway operator’s timetable to dimension the hydrogen refuelling station compressing capacity and onsite high-pressure storage
• Working with key sector players on refuelling protocols and communication technologies between the vehicle and the refuelling station to create solutions and influence international standards.

Alstom produces battery trains for both regional and commuter networks, known as battery-electric multiple units (BEMUs). The power-pack dimensioning and optimisation of passenger trains depends on various parameters such as the length and the topography of the non-electrified line as well as the timetable. Alstom is capable to optimise its battery traction package utilising its sophisticated energy consumption tool, which is capable to simulate the train behaviours under customer specific conditions. For example: high acceleration rates at stations in urban areas demand more energy. On the other hand, having many stations on a line, such as in sub-urban areas, provide kinetic energy from braking, which is then fed back to the battery. Train operations are most energy-efficient when driving at steady speed on longer, regional tracks. Alstom’s driver advisory system gives guidance.