📌 Decarbonising transport, a transport infrastructure perspective

Port, airport, and rail infrastructure are facing a dual challenge with regard to decarbonisation: decarbonising their own activities, and accommodating the next-generation, clean energy vectors to power the vessels, planes, trains they serve, as well as ancillary vehicles.

Futura-Mobility explored this topic during its latest session, on 15 November, with three experts from SNCF Réseau, Group ADP Group, and HAROPA PORT.

Group SNCF’s carbon neutrality by 2035 goal calls for new solutions that take into account the company’s financial constraints. For SA SNCF Réseau, the network infrastructure manager, “it’s about controlling costs to make decarbonisation projects feasible by this deadline,” explains Philippe Berthier, head of the electric traction department at SNCF Réseau.

On the airport side, Group ADP has an SBTi (Science Based Targets initiative) validation aligned with the Paris Agreement for all its hubs – which “means zero net emissions by 2050,” explains Blandine Landfried, director of Group ADP’s climate and sustainable air transport division. “To achieve this, we are committed to reducing our carbon emissions, both direct from our airports and from our stakeholders, mainly airlines and their aircraft, by at least 90% between 2019 and 2050.” One pillar of the Group’s decarbonisation strategy involves transforming its airports into energy hubs, so that they can produce and distribute new, low-carbon energies.

For HAROPA PORT, the authority managing the ports of Le Havre, Rouen, and Paris, the biggest challenge is “encouraging and supporting partners based on or near our sites to decarbonise,” explains Cédric Virciglio, HAROPA PORT’s director of strategic planning and forecasting.

Decarbonisation solutions and innovations

• Electrification, a crucial lever

For these three players, electrifying infrastructure, while not the only solution, is playing a key role in this transition. At SNCF Réseau, decarbonising through electrification is currently focused on lignes de desserte fine du territoire (LDFT), rail lines throughout France providing everyday travel services organised and financed by the Regions, or Île-de-France Mobilité in the Paris region. “Today, many LDFTs are not electrified, which means we can test different solutions on these routes and also be in direct contact with regional stakeholders and organising authorities.”

Setting up a MiniLab within SNCF Réseau around 5-6 years ago gave rise to the notion of frugal electrification. The idea is to take advantage of the emergence in recent years of new opportunities linked to coupling between innovations in rolling stock and what infrastructure can put in place to make the best use of these new technological opportunities. It’s “a system vision to overcome the cost barrier of electrifying lines for the regions of France,” explains Mr Berthier. One of the solutions arising from this approach is the dual-mode electric-battery train, which means low-traffic lines can shift away from diesel without having to be electrified in their entirety. Another focus of this frugality work specifically concerns the ‘last mile’ journeys of freight locomotives: the MiniLab team is seeking far more frugal solutions in terms of electrification costs. “These freight trains run slowly over the last few kilometres of their journey, at around 30 or 40km/hr,” explains Mr Berthier. “So rather than installing catenary systems for trains travelling at 160km/hr, we’re going to look at catenary technologies for these sections that will cost us less.”

A third approach being studied by the MiniLab is adapting electric currents. Part of the rail network is electrified at 25,000 volts, and another at 1,500 volts DC. A lot of work is currently underway on these DC power supply technologies to increase voltages and so improve performance and reduce losses. “This is interesting for us because it could be done with virtually the same infrastructure, but the rolling stock will have to be compatible with these voltages, so manufacturers will also have to make an effort.”

Electrifying ground and in-flight operations at Group ADP airports involves a great many actions. These range from developing alternative energy and hydrogen stations to power ADP’s taxi and internal vehicle fleets to advancing recharging infrastructure for tomorrow’s electric aircraft. For the Paris airports alone, the electricity requirements generated by all their ground operations will require an approximate 1.5-fold increase in the power currently available. ‘This will mean a major overhaul of the infrastructure to make our electricity network more reliable and capacitive,” explains Ms Landfried.

For inland waterway transport, HAROPA PORT, working with Voies Navigables de France (VNF), has developed a network of some 100 charging points, to begin with for barges as well as cruise ships  to plug in to the quayside, then later on for recharging batteries when propulsion is fully electric – a programme co-financed by the European Union. “In our ports, we are also working on the container section to bring electricity quayside,” says Mr Virciglio.

• Energy diversification and optimising use

Ammonia, methanol, SAF (Sustainable Aviation Fuels), hydrogen, biomass, geothermal energy, photovoltaics…. Diversification of energy sources offers another pathway for these stakeholders to decarbonise their activities.

To this end, HAROPA PORT is looking to install companies on its land capable of producing a maximum of green energy. The Authority has biomethane facilities, notably at the Port of Gennevilliers in Ile-de-France, and is installing photovoltaic panels on the rooftops of warehouses or hangars in its ports. The same is true of Group ADP, which already uses geothermal energy to provide hot water and is investing in solar farms “in sunnier parts of France than the Paris region,” says Ms Landfried. The Group is also planning to install solar panels at its Paris airports and is studying the possibility of solarising its grasslands, “taking special care that installing these panels does not destroy biodiversity,” reassures Ms Landfriend. “Our 2030 objective is to ensure that 30% of our electricity is supplied by our solar production,” she sums up.

From among the emerging technologies, Group ADP is already carrying out studies with a view to storing hydrogen – “the technology that represents the biggest challenge for our airports, since it will require new end-to-end management of the logistics chain,” points out Ms Landfried. At HAROPA PORT, 35 projects to produce hydrogen along the Seine axis are ongoing with stakeholders like Air Liquide and Airbus (see slide below).

For Group ADP, hitting its in-flight decarbonisation targets will depend 50% on the new-generation SAF fuel, which will replace traditional jet fuel in the years to come. Hence the importance of anticipating tomorrow’s needs. “We’re investing CAPEX in developing plants to produce SAF,” confirms Ms Landfried.

Another decarbonisation pathway is optimising energy. Among the options evoked during the session, SNCF Réseau is studying train braking energy recovery and looking at how, with storage elements or reversible substations, this energy could be re-injected into other consumer elements. Creating smart grids is another energy optimisation solution being analysed.

“We have fairly advanced studies on the rail smart grid to understand how energy is used and how it can be managed more effectively,” confirms Mr Berthier. This involves, among other infrastructure, the substations feeding the rail network with electricity supplied by RTE and Enedis. Tomorrow, as part of a smart grid, they could also be partially powered by photovoltaic panels, battery systems, or hydrogen-based, energy production systems. “We could also inject this flow of energy into the substations and feed it back into the train in the same way, but with smart management of this energy to optimise use of the different types of production,” explains Mr Berthier.

Developing power electronics technologies is extremely important for the rail sector. They will make it possible to reduce imbalances on the network, limit disruptions on the lines, and so better manage the energy efficiency of lines.

This preparatory work is paving the way for a rail smart grid in 2040-2050. By then, SNCF Réseau will be in a position to manage energy dynamically, “thus shifting from a passive, one-way network to a reversible and controllable grid,” adds Mr Berthier.

The smart grid is also part of Group ADP’s strategy. “We are looking into the possibilities of the smart grid for matching electricity supply and demand across our airports through renewable energy [EnR], production, and battery storage systems,” confirms Ms Landfried.

Pathways to decarbonisation – challenges, constraints and collaboration

From the complexity of modifying existing infrastructure to managing multifarious supply chains for new fuels, this decarbonisation drive involves a considerable number of economic, technical and logistical challenges and constraints.

One of the challenges is uncertainty over the availability and quantities of alternative fuels. “As far as decarbonisation is concerned, we are preparing for the ports of tomorrow to be able to refuel with energies like ammonia, hydrogen or methanol, but we don’t know which energies will be those of the future,” admits Mr Virciglio. “What we do know is that there won’t be sufficient quantities in the medium term to supply all vessels. Hence the need to produce as much as possible ourselves.”

Philippe Berthier insists that being capable of maintaining these advanced technologies – which will transport SNCF Réseau into a new generation of infrastructure – will call for significant social and human support. “These are extremely promising technologies, but our maintainers, for instance, who are just discovering them, don’t yet have sufficient expertise on them.”

Rail, air, sea and river infrastructure involve many physical and organisational elements. Given this complexity, in addition to considerable levels of financial investment, decarbonisation necessarily involves all the stakeholders active in these ecosystems.

Maintaining relations and dialogue with organising authorities, for instance, is key to the success of this transition at SNCF Réseau. “The organising authorities are obviously very demanding when it comes to the cost of rail projects, especially electrification projects, and this is a vital variable to take into account in our approach,” confirms Mr Berthier. The same applies to Group ADP, which is working with local authorities to set up a new heating network in the communes of Dugny and Le Bourget in the Paris region. By linking up with this network, Le Bourget airport will deliver the benefits of low-carbon thermal energy to more than 60% of the companies operating on its site.

Incentive regulations are also crucial to encouraging uptake of these alternative types of infrastructures, as are changing mindsets. “If there are no binding regulations, shipowners plug in rarely or never at the quayside because it’s cheaper to leave the engine running and burn fuel,” deplores Mr Virciglio. “We could increase our (river) barge traffic by a factor of 6 without any problem,” he adds. “The issue here is the ‘all truck’ mentality that has prevailed in France since the 1950s.”

The session ends with a presentation on ports of the future. Frédéric Descombes, head of the Ideas Laboratory hub at CEA, presents the three scenarios devised by the partners of the Infraport project (June 2024) to meet the challenges facing tomorrow’s seaports. This long-term vision is knowingly quite a leap from the topic of today’s session.

The scenarios presented are based on a strategic exploration that seeks to respond to several challenges: climate change (rising sea levels, storms and extreme heat), changing business models, water and data management, new governance, land ownership, security, and so forth.

The island port: underground

The port remains on its original site, but will go underground. This involves unloading containers and transporting people through underground tunnels linked to the land.

The oyster port: protected and filtering

A port using local materials to build, close and protect itself. Buildings close in on themselves depending on climatic conditions, or a huge dyke serves for protection. Water management is becomes a new business model.

The polymorphic port: multi-purpose

A set of interconnected floating structures built from end-of-life ships. This concept integrates living spaces, producing energy, fresh water, and food, and maritime traffic management.

Each scenario proposes innovative solutions for adapting to future climate conditions, while maintaining essential port activities. Emphasising the importance of energy, water management, and data pooling at ports of the future, Mr Descombes pointed out that these scenarios are exploratory and aim to stimulate innovation in the port sector.