PhD defence on 17 December 2026
On 17 December 2026, Melissa CHERROUK will defend her thesis on multi-objective optimisation for the design of hydrogen supply chains incorporating offshore wind energy.
Her research, supervised by Catherine AZZARO-PANTEL (Institut National Polytechnique de Toulouse) and Florian DUPRIEZ-ROBIN (France Energies Marines), was carried out as part of the OPHARM2 project (2023–2026) which focused on an advanced analysis of offshore hydrogen production using offshore wind turbines.
Abstract
Floating offshore wind offers the possibility of producing renewable hydrogen directly at sea through electrolysis, with subsequent transport to shore. This configuration raises specific challenges related to the integration of offshore electricity generation and hydrogen production, the sizing and location of facilities, and the transport of hydrogen to demand centres. Its assessment also requires accounting for the temporal variability of wind resources and the economic and environmental trade-offs between alternative hydrogen production pathways. This thesis thus investigates the design and optimisation of regional hydrogen supply chains integrating offshore hydrogen production and onshore production alternatives.
A spatial mixed-integer linear programming model is extended to integrate offshore configurations and associated investment decisions across multiple investment periods. To account for offshore wind variability, a temporal downscaling approach based on k-means clustering and Fourier analysis ais developed and compared with an average-availability formulation. Multi-objective optimisation is performed using an augmented epsilon-constraint procedure to explore the trade-offs between levelised cost of hydrogen (LCOH) and global warming potential (GWP) intensity.
The approach is applied to regional hydrogen supply chains in Occitanie, southern France.
The results show that cost minimisation progressively favours unabated natural-gas reforming, whereas GWP minimisation selects low-carbon electrolysis, including offshore production. The representation of offshore availability through four weighted regimes changes the infrastructure configurations selected by the model and, under GWP minimisation, yields an 11.4% lower LCOH than the average-availability formulation, at the same reported GWP intensity. Multiobjective analysis places offshore production only near the lowest-GWP end of the computed trade-off.
A further analysis considers more realistic assumptions and a joint clustered representation of offshore-onshore wind and photovoltaic availability. A compromise between economic and environmental objectives reduces GWP intensity by approximately 85% for a 24% increase in
LCOH relative to the lowest-cost configuration without offshore electricity. However, access to nuclear electricity, represented by a gross regional generation envelope, is more permissive than access to renewable electricity. In the selected low-GWP configurations, increasing the offshore allocation to 100% raises its contribution to regional hydrogen production in 2050 from 6.3% to 35 %, mainly replacing nuclear-powered electrolysis.
The results show that the role of offshore wind in regional hydrogen supply depends on its interaction with competing production pathways, electricity-access assumptions and economic and environmental objectives. They also highlight the influence of temporal resource representation and allocation assumptions on regional supply-chain design.
Composition of the jury
- Zita VALE, Professor, Instituto Politécnico do Porto – Rapporteur
- Assaad ZOUGHAIB, Professor, Mines Paris – PSL – Rapporteur
- Xavier ROBOAM, Research Director, LAPACE Laboratory, CNRS – Chairman
- Kenneth BRUNINX, Associate Professor, Delft University of Technology – Examiner
- Catherine AZZARO-PANTEL, Professor, Institut National Polytechnique de Toulouse – PhD Director
- Florian DUPRIEZ-ROBIN, Research Projects Manager, France Energies Marines – PhD Joint Supervisor
