Eiffage Installs Substation for eRoadMontBlanc
The eRoadMontBlanc research and development project is a groundbreaking initiative aimed at significantly decarbonizing road freight and long-distance mobility in France and across Europe by 2030. At the heart of this effort is the adaptation of Alstom’s Ground Power Supply (APS) system—originally developed for the Bordeaux tramway—to Electric Road Systems (ERS), an innovative technology that allows electric vehicles to charge dynamically while in motion.
Establishing an Open-Air Laboratory for ERS Testing
Near Lyon, in Saint-Maurice-de-Rémens (Ain department), an advanced open-air laboratory has been set up at the Transpolis Innovation and Safety Testing Center. This center, located on a former military site dating back to the 1930s, provides an ideal environment for rigorous experimentation on ERS technology.
The test track at this facility spans 418 meters and is fully equipped with Alstom’s APS system. To power this infrastructure, Eiffage Énergie Systèmes was responsible for the design and construction of an advanced electrical substation between March 7 and December 12, 2024. This substation consists of two specialized shelters, each playing a crucial role in energy distribution.
Technical Details of the Electrical Substation
The substation’s primary function is to convert and deliver electrical power efficiently to the APS-equipped roadway. This process begins at an existing transformer station, where energy is routed through a high-voltage (HVA) shelter.
“We connected a first HVA shelter containing HV cells, two HVA/LV transformers, and a rectifier that converts AC energy (585 V) into 750 V DC, mimicking the power supply of a tramway system,” explains Frédéric Aïta, the project manager.
The system’s core traction technology is housed in a separate low-voltage (LV) shelter, where Alstom’s electrical cabinets have been installed. From this shelter, power cables extend to the test track, passing through an injection inspection chamber and 19 strategically placed inspection chambers, each outfitted with a power supply box.
Dynamic Charging for Electric Freight Transport
The ERS technology at eRoadMontBlanc enables electric trucks to receive power while moving, significantly reducing dependency on large onboard battery packs. Power is injected into the road at 11-meter intervals, allowing trucks and other electric utility vehicles traveling between 30 and 90 km/h to seamlessly connect to conductive rails embedded in the road surface. These conductive rails transfer energy via friction pads, a contact-based charging method that ensures efficient power delivery.
One of the primary advantages of this dynamic charging system is its potential to optimize battery size and weight. Instead of requiring massive battery packs to sustain long-haul routes, electric trucks equipped with this system can recharge incrementally while driving, extending their operational range without the need for lengthy charging stops.
Next Steps: Real-World Testing and Expansion
The eRoadMontBlanc project is structured in multiple phases. The first phase, currently underway, involves controlled testing on a closed test track within the Transpolis center. If successful, the project will advance to phase two, where the APS system will be deployed on a 1-kilometer section of the N205 highway near Les Houches, in Haute-Savoie.
“This second phase will allow us to test the APS system under more challenging real-world conditions, including significant temperature fluctuations, varying altitudes, and a 4% gradient,” Aïta explains.
Competing Technologies in the ERS Sector
The eRoadMontBlanc demonstrator is one of several competing technologies being tested for large-scale implementation across Europe. Alongside Alstom’s ground-based conductive APS system, two other major approaches are currently under evaluation:
- Overhead Catenary System (OCE): Developed by Siemens in Germany, this system employs overhead electric wires similar to those used by electric trains and trolleybuses. Trucks equipped with pantographs can connect to these wires for charging while driving.
- Inductive Wireless Charging System: Developed by Israeli company Electreon, this technology uses electromagnetic induction to wirelessly transfer power to vehicles. While it allows electric trucks to operate without physical contact with the road, it does not support simultaneous battery charging, limiting overall range extension.
According to Aïta, the APS system has a distinct advantage over the wireless inductive method:
“The induction power system allows electric trucks to drive but does not charge their batteries. By contrast, Alstom’s APS system enables trucks to draw between 400 and 500 kWh of energy, with 100 to 150 kWh used for propulsion and the remaining 350 kWh for battery recharging. This means that when a truck leaves an APS-equipped ERS, it has an additional 200 km of range.”
Future of Electric Roads in Europe
Following the results of these pilot projects, the European Union will select the most effective ERS technology to deploy on a large scale. The chosen system will be implemented on France’s 8,800 km of motorways and, ultimately, across Europe’s highway network.
The implications of this transition are substantial. A successfully deployed ERS could dramatically cut carbon emissions from road freight, reduce reliance on fossil fuels, and make long-haul electric trucking a viable and cost-effective solution.
