Good morning, ladies and gentlemen. My name is Maud, I hold a PhD in energy engineering from the University of Corsica, and I currently work as a research engineer on the H2Move project, an Interreg Marittimo project. Its goal is to propose solutions to improve territorial continuity and reduce environmental impacts — that is, to cut the greenhouse-gas emissions of port areas using green hydrogen.
The project brings together several stakeholders: port authorities from various Italian regions (such as Sardinia), the French chambers of commerce and industry (notably those of the Var and Corsica), as well as universities and green-energy research centres.
I will present the work we carried out within this project, entitled "Integrating the hydrogen vector to decarbonise Corsica's port areas." I will start by recalling Corsica's energy context and challenges, then focus on the maritime sector and its possible decarbonisation. I will move on to a state of the art of the hydrogen sector in Corsica, before presenting the model we developed, the case study, some results, and the conclusion.
Corsica's energy context
Corsica is a Mediterranean island that belongs to France's group of non-interconnected zones: its power grid is partially interconnected with Italy and Sardinia, but not with mainland France. This geographic position also makes it dependent on external imports for its supply of freight and goods.
Several problems follow from this. First, the island's electricity production rests on an energy tripod: one third from fossil sources, one third imported, and one third renewable (mostly hydro and solar). This generation mix results in a cost four times higher than on the French mainland and in much more carbon-intensive electricity.
A second issue is ships at berth. During their stopover, ferries run their onboard auxiliary generators, which burn fossil marine fuels and emit not only greenhouse gases but also air pollutants (sulphur oxides, nitrogen oxides, fine particles). Since ports are generally located in city centres, the impact on residents' health is significant.
For 2050, the Corsican Assembly has adopted an energy-autonomy target, which requires reducing greenhouse-gas emissions, lowering final energy consumption, and shifting to fully renewable electricity. The main lever identified is the use of local renewable resources and their valorisation through storage systems or energy vectors such as hydrogen — produced by water electrolysis powered by renewables, then used for mobility (urban buses, heavy trucks) or in stationary applications (conversion back to electricity for port areas or neighbourhoods during consumption peaks).
Decarbonising the maritime sector
Corsica has 28 marinas and 6 commercial ports. The latter handle 3.6 million tonnes of goods (2023) and a large passenger flow — around 4.3 million per year, concentrated in the summer season.
For the port of Ajaccio alone, the port area represents an electricity consumption of 2,247 MWh, entirely covered by grid imports — about 1,000 tonnes of CO₂ equivalent per year and an energy bill of €607,000. Ferries at berth represented, in 2023, a consumption of 5,869 MWh, supplied by their auxiliary generators: 495 tonnes of marine fuel, i.e. 5,000 tonnes of CO₂, 82 tonnes of nitrogen oxides, 2 tonnes of sulphur oxides (the Mediterranean being a SECA zone, with low sulphur content) and 2 tonnes of fine particles.
According to the International Maritime Organization (IMO), the maritime sector currently accounts for 2.9% of human-origin emissions. Its emission-reduction strategy, adopted in July 2023, targets −20% by 2030, −70% by 2040 and carbon neutrality by 2050. Four levers were identified: lower-carbon fuels, electrification of ships at berth, greenhouse-gas capture and storage, and nuclear propulsion. Not all are applicable to Corsica; the most relevant there is the electrification of ships at berth.
A ferry's energy profile shows a peak on arrival, consumption during the stopover, then a peak on departure. A key criterion is the stopover duration: according to the reports we studied (Sweden, Crete), it must exceed 4 hours for technical feasibility, with profitability improving the longer the stay. We modelled the consumption of Ajaccio's 5 berths: 1,217 stopovers, ranging from 20 minutes to 13 hours. For the study, we kept stopovers longer than 6 hours at the 3 most consuming berths, i.e. 5,870 MWh.
Comparing three scenarios — no shore connection (current situation), connection on the current Corsican electricity mix, and connection on a future, mostly renewable mix — we see a 30% drop in emissions and the elimination of air pollutants as soon as the ships are connected to the current mix, and up to −90% carbon intensity with the future mix (78 kg CO₂/MWh, the value targeted by the PPE).
The state of the hydrogen sector in Corsica
Corsica's hydrogen sector is fairly well developed: three existing projects and four under preparation, including two at the ports of Ajaccio and Bastia. Hydrogen already appeared in the 2013 regional climate-energy plan (100 GWh of electricity dedicated to its production). The multiannual energy programme (PPE), drafted in 2015 and updated in 2019, proposes three strands: grid support, cogeneration, and decarbonisation of maritime and land mobility (bus and boat fleets, electrification of ships at berth). It is from this proposal that our model starts.
The energy model developed
The base model represents only the island's high-voltage electrical system: distribution substations are linked by overhead or underground lines, each substation carrying the consumption of the municipalities connected to it, along with static generators (thermal plants) or intermittent ones (PV farms, wind farms).
This model is embedded in an optimisation module that minimises the total system cost, with the nominal power ratings of generators and the nominal capacities of storage systems as decision variables, under the key constraint of meeting the loads at all times. The output provides the optimal sizing of all components and the most cost-effective distribution of energy flows.
The model we propose adds hydrogen chains: hydrogen nodes producing hydrogen via an electrolyser and consuming it via fuel cells, with a compression and distribution stage for transport applications, tanks (high or low pressure) and loads corresponding to consumption (buses, grid service).
Concretely, at each of the 33 electrical nodes a low-pressure hydrogen node can be added (via an electrolyser), which can then feed an electrical node via a fuel cell (grid service, ships at berth, airport GPUs), or, after compression to high pressure (e.g. 350 bar), supply bus fleets or hydrogen trains. For this presentation, we focus on a low-pressure hydrogen node (electrolyser + fuel cell) intended to power ships at berth.
The case study: the six commercial ports
We modelled the consumption of the port areas by assigning a share of consumption to different consumers, then added this profile to that of the ferries at berth. In Ajaccio, for example, the maritime station's consumption rises in summer with the increased footfall.
The total annual energy consumption of the ports reaches 39.5 GWh, with Ajaccio and Bastia as the main consumers (between 11.6 GWh/year and 2.3 GWh/year for the smallest ports). Daily consumption breaks down into four periods: (1) port area + ferry arrival, (2) port area + ferries during the stopover, (3) port area + ferry departure peak, (4) port area only, mainly at night.
Sizing results
The per-port sizing gives:
Photovoltaics: 66.7 MW in total, of which ~23.3 MW at Ajaccio and Bastia, and 1.9 MW at L'Île-Rousse.Electrolysis: ~22.3 MW for all ports.Fuel cells: 27.3 MW in total.Hydrogen storage: 1.9 tonnes in total (396 MWh), from ~180 kg for small ports such as L'Île-Rousse up to 3.9 tonnes for Bastia, for a total production of 590.7 tonnes of hydrogen.The CAPEX is dominated by the storage requirement, which is high because the solar production has to be restored when it is not available. The total OPEX amounts to €3.8 million, of which 32% comes from grid imports.
Solar production is dominant everywhere: it covers part of the load (port area + ferries) and part of the hydrogen production, with electrolysers running 4 to 7 hours per day, in step with sunshine. Grid imports remain low, except at L'Île-Rousse (a smaller port with less solar production, hence less available hydrogen). At Ajaccio, hydrogen is produced during the day from the solar surplus and the fuel cell is used more, with a single recourse to the grid; at L'Île-Rousse, the grid is called upon several times.
Ports of today and tomorrow
Today, the port of Ajaccio imports its electricity from the grid and burns marine fuel oil for ships at berth: 495 tonnes of marine fuel and 2.3 GWh/year, i.e. up to 500 tonnes of CO₂ and non-negligible pollutants.
If all Corsican ports were supplied solely by the current grid, there would be no installation cost but an OPEX of €15 million (purchase at production cost) and a high carbon intensity (4,000 t CO₂). Conversely, ports supplied tomorrow by a hybrid plant (PV + hydrogen + grid as backup) would require a CAPEX of €18 million, but a lower annual OPEX and, above all, a carbon intensity divided by four, with the cost of electricity brought down to ~€130/MWh. The hydrogen production cost comes out at €7.85/kg — higher than the European target of €6/kg, but it includes installing systems that do not yet exist on the territory.
Conclusion and outlook
This work shows that, by making optimal use of the solar potential, it is possible to decarbonise all of the island's port areas through a renewable solar + hydrogen mix, at a cost of about €7.85/kg of hydrogen, and to extend the applications to other consumers to create a genuine ecosystem for each city. Several barriers remain: the installation areas required, regulation, the still-high installation costs of hydrogen systems, and the management of auxiliary systems.
Outlook: a finer modelling of the hydrogen and auxiliary systems, on shorter time steps to optimise management, and a geospatial study in QGIS to determine the precise locations of the equipment — as was done for the port of Toulon. Thank you for your attention.
Audience questions
Accounting for airports (Irwin Kerborio). Yes: we included the consumption of aircraft at the gate for the potential conversion of current GPUs. A hydrogen aircraft was not taken into account but could be, just like hydrogen-powered ships, in order to aim for full decarbonisation of the sector.
Involvement of EDF SEI (Brittany region). EDF SEI is not among the partners of the H2Move project (Italy, Sardinia, Corsica, Var). It is the regions that are involved, not the island electricity supplier.
Transferability to other ports such as Marseille (Christophe Bessier). These studies are beginning to be carried out in several ports (Livorno, or Toulon for a fuel cell, a fairly advanced study). The model is specific to Corsica since it is the Corsican power grid that was modelled, but the hydrogen part could be transferable, subject to verification.
Cost of hydrogen (Julien). The figure shown is a production cost over the systems' lifetime (~10 years), based on current investment costs for electrolysers, fuel cells and storage. If these costs doubled, the pump price would rise accordingly (the sale cost must also be added). But these deployments are envisaged for the long term (2050 horizon), with an expected decrease in equipment costs.
Identifying the best solar sites (Thomas Sommatia). Yes, this is planned, in collaboration with various regional partners and through the geospatial approach — for solar as well as for hydrogen, which will not necessarily be produced at the port. Part of this work aims to present a hydrogen roadmap integrating the various consumption and production points.
