Bombardier Transportation (now part of Alstom) introduced a variety of green innovations to reduce CO₂ emissions and pollution in the railway sector. One of our first sustainable mobility solutions was a dual-mode Autorail à Grande Capacité (AGC) train, designed and developed by its Crespin site in France; the AGC was the world’s first hybrid train when it entered service in 2007.

With 2,473 AGC train cars in operation today, the AGC is the largest regional fleet operated in France. To help France meet its sustainability targets, Bombardier will now convert AGC hybrid trains to full battery power. The effort is part of France’s strategy to eventually phase diesel power out of its national rail fleet.

In January 2021, Bombardier signed a new contract to retrofit and to introduce a pre-series of five prototype AGC battery-operated trains by 2023, in collaboration with SNCF Voyageurs and five French regions including Auvergne-Rhône-Alpes, Hauts-de-France, Nouvelle-Aquitaine, Occitanie and Provence-Alpes-Côte d’Azur.

The partners will modify existing AGC trains into battery-operated trains to help decarbonize French rail transport. The idea is to convert dual-mode (catenary and diesel-powered) high capacity self-propelled trains to dual-mode battery-powered AGCs.

This project is a response to the growing demand for emission-free solutions; these five dual-mode battery-catenary trainsets will be used as demonstrators. The range in battery mode will be at least 80 kilometers. The current range will allow the dual-mode battery-powered AGCs to perform the same missions as the current AGCs (diesel-catenary) and Bombardier wants to increase that autonomy.

Bombardier is ideally positioned to carry out this greening project, since nearly 50% of the diesel rail fleet in France consists of AGC trains built at Crespin.

This AGC battery project is the only one that offers a “greening” transformation of existing trains, and the project will be undertaken as part of the fleet’s scheduled midlife maintenance. The project also provides a unique opportunity to capitalize on existing assets and avoid unnecessary renewal of installed rolling stock fleets. But perhaps most importantly, it offers a proof of concept and a way forward to eliminating diesel trains by 2035, a target set by the French government and SNCF.

It also reduces the cost of energy consumption, due to lower electricity costs compared to diesel-fueled trains. AGC battery-electric multiple units (BEMU) can store braking energy and use it for upcoming acceleration, offering major energy savings, plus 15% higher peak power.

In addition to diesel operation, the performance of France’s electrified network is often bound due to limitations in line power. Using battery to complement catenary-power during peak acceleration will not only improve the eco-profile of the AGC fleet, but also improve overall operations.

Technicians will remove the trains’ diesel packs and replace them with four battery units each. Then they will add the necessary high-power charger to transfer energy between batteries, traction equipment and pantograph. Next, the trains’ control system will be adapted to work with the new propulsion system. This AGC upgrade project has been selected as one of the French Government and rail sector’s top strategic innovations.

The renovated battery-powered AGC trains will bring excellent energy efficiency by limiting energy lost during charging and discharging. Excess energy that cannot be stored or regenerated during braking represents 10 to 30% of the total energy used by a train. Energy is also frequently lost when running on parts of the French network that is electrified with 1.5 kVDC, where energy regeneration during braking isn’t allowed, and when the trains are running on diesel power, braking energy is also lost.

Battery EMUs will be able to store the braking energy and use it when required, offering strong energy-savings and a sustainable mobility solution.