BECOME
This century is marked by a race against time to limit global warming to 1.5 °C above pre-industrial levels, as agreed in the Paris Agreement by 192 Parties in December 2015 [1]. In this context, technologies using decarbonized hydrogen have become a national priority for many countries [2, 3]. As disruptive innovations, they promise to decarbonize the most energy-intensive sectors (industry, transport, energy storage) and to reduce the real costs (environmental, climatic, health-related) across the energy value chain, from conversion to end-use [4]. In particular, they play a crucial role in decarbonizing the steel and fertilizer industries, electrifying heavy transport, and storing electricity from intermittent or seasonal renewable energy sources (RES). On the scale of non-interconnected grids, such as those in island territories, the hybridization of multi-source conversion units relies on the deployment of storage systems, both to decouple energy production and demand from the availability of local RES and to manage the complementarity of variable and flexible resources. Storing energy in the form of hydrogen and its stationary reconversion into electricity help mitigate the intermittency of variable RES by optimizing electrical production capacity.
Currently, the proton exchange membrane fuel cell (PEMFC) is the most widely adopted fuel cell technology [6]. However, it faces technological challenges that must be overcome for large-scale commercialization, such as low power densities, high costs, and limited lifespan [7]. In particular, the transient operating conditions induced by RES variability lead to performance, reliability, and durability issues in hydrogen systems: cell degradation, premature aging, or the occurrence of faults (water management, corrosion, etc.). To address these challenges, global institutions have set several development targets for PEMFCs. Regarding power and current density improvements, the European Union aims to reach 1.2 W·cm⁻² at 0.675 V by 2030 [8], while Japan targets 6 kW·L⁻¹ and 3.8 A·cm⁻² for the same year [7]. For cost reduction, the European Union seeks a price below €50/kW by 2030 for fuel cells in heavy-duty vehicles [8]. Finally, concerning lifespan, the European Union aims for 30,000 operating hours for hydrogen buses by 2030 [8].
Numerical modeling of fuel cells contributes to achieving these development goals. Indeed, models provide insights into the internal states of cells that traditional sensors cannot capture, as placing them directly inside the ultra-thin cell layers is impractical. With this precise information, PEMFC diagnostics can be enhanced [9, 10]. This enables more effective real-time control of fuel cells by adjusting operating conditions—such as pressure, temperature, humidity, and gas flow rates—which can improve performance, prevent faults like cell flooding, and reduce degradation.
The general objectives of the OPUS-H2: « Optimization of Performance and dUrability of hydrogen Systems using an advanced digital twin » project, led by Prof. Michel Benne and running from May 2025 to May 2027, are to significantly contribute to the development of numerical models for PEM fuel cells in order to improve their performance and durability, as well as to build experimental expertise in collaboration with ZSW, a well-established European partner in the field, with the aim of transferring these skills to Réunion Island. The sharing of knowledge and cross-disciplinary expertise within this partnership will foster innovation and research.
The OPUS-H2 project is funded by the European Union with a grant of €136,060.78 under the FEDER-FSE+ Réunion program, with the Réunion Region acting as the managing authority. Through the FEDER fund, Europe is committed to supporting Réunion. The Région Réunion complements this funding with a national co-financing contribution of €24,010.72.
Sources:
[1] The Paris Agreement, United Nations 2015 (https://unfccc.int/documents/9064)
[2] The Future of Hydrogen. Seizing Todayʼs Opportunities, IEA 2019 (https://www.iea.org/reports/the-future-of-hydrogen)
[3] Y. Wang et al. 2011 (10.1016/j.apenergy.2010.09.030)
[4] Panchenko et al. 2023 (10.1016/j.ijhydene.2022.10.084)
[5] Stratégie Nationale Pour Le Développement de l’hydrogène Décarboné En France, Gouvernement français, Dossier de Presse 2020 (https://www.economie.gouv.fr/presentation-strategie-nationale-developpement-hydrogene-decarbone-france)
[6] A. Dicks et al. 2018 (ISBN 978-1-118-70697-8 978-1-118-61352-8)
[7] K. Jiao et al. 2021 (10.1038/s41586-021-03482-7)
[8] Clean Hydrogen Joint Undertaking. Strategic Research and Innovation Agenda 2021 – 2027 (https://www.clean-hydrogen.europa.eu/about-us/key-documents/strategic-research-and-innovation-agenda_en)
[9] Fei Gao et al 2010 (10.1109/TIE.2009.2021177)
[10] J. Luna et al 2016 (10.1016/j.jpowsour.2016.08.019)
This project builds upon the doctoral work of Raphaël Gass, which led to the development of a dynamic 1D physical model of a PEM cell with auxiliaries, named AlphaPEM, serving as a building block for a fuel cell digital twin. Based on this model, a control strategy for inlet humidity was formulated, theoretically enabling a 60% increase in cell power output or a 15% improvement in efficiency.
The OPUS-H2 project advances this work through five specific objectives:
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Development of the digital twin and inlet humidity control strategy by adding new functionalities to AlphaPEM.
- The first aim is to improve the accuracy of the AlphaPEM model by enabling it to simulate additional physical phenomena. Six tasks are implemented to achieve this:
- refining the model simulating electrochemical impedance spectroscopy (EIS) curves,
- adding a thermal phenomena model to AlphaPEM,
- incorporating the microporous layer (MPL) into the PEM cell modeling,
- using improved auxiliary control tools,
- increasing the spatial dimension of the single-cell model to 1D+1D,
- precisely characterizing multiple cells forming a stack.
- The second aim is to enhance the inlet humidity control strategy developed in previous work. Three tasks are implemented to achieve this:
- using improved tools for controlling operating conditions,
- further developing the theory on the limiting liquid water quantity (slim), established in prior work, linking voltage drop at high current densities, liquid water content in the cell, and its operating conditions,
- refining the inlet humidity control strategy based on the results of this action.
- The first aim is to improve the accuracy of the AlphaPEM model by enabling it to simulate additional physical phenomena. Six tasks are implemented to achieve this:
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Conducting experiments on test benches to validate AlphaPEM and verify performance gains obtained through simulations.
- The objective is to perform experimental tests on the European partner’s equipment to validate AlphaPEM improvements and the proposed inlet humidity control strategy. Three tasks are implemented to achieve this:
- generating polarization and EIS curves under different fixed operating conditions on near-single-cell stacks,
- generating polarization and EIS curves under model-controlled operating conditions on near-single-cell stacks,
- repeating tests on stacks of around one hundred cells.
- The objective is to perform experimental tests on the European partner’s equipment to validate AlphaPEM improvements and the proposed inlet humidity control strategy. Three tasks are implemented to achieve this:
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Integration of models into the digital twin to estimate cell degradation state and remaining system lifespan.
- The objective is to enable AlphaPEM to account for the current degradation state of an experimental stack and incorporate this impact into the results. Two tasks are implemented to achieve this:
- integrating a model to estimate electrochemical surface area (ECSA) degradation in the catalytic layer into AlphaPEM,
- integrating a model to calculate the system’s remaining useful life (RUL).
- The objective is to enable AlphaPEM to account for the current degradation state of an experimental stack and incorporate this impact into the results. Two tasks are implemented to achieve this:
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Development of model-based control strategies to maintain optimal performance and reduce degradation over the cell’s lifetime.
- The objective is to apply the theory produced in the objective 3 to create an operating condition control strategy that maximizes performance and minimizes future degradation in an aged stack. Two tasks are implemented to achieve this:
- developing a control strategy for operating conditions, based on AlphaPEM, to maintain maximum performance of an aged stack at all stages of its life,
- developing a control strategy for operating conditions, based on AlphaPEM, to minimize future degradation of an aged stack at all stages of its life.
- The objective is to apply the theory produced in the objective 3 to create an operating condition control strategy that maximizes performance and minimizes future degradation in an aged stack. Two tasks are implemented to achieve this:
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Conducting accelerated degradation experiments on test benches (single cells and stacks) to validate digital twin enhancements and formulated control strategies.
- The objective is to perform experiments on the European partner’s test benches to validate the proposals from objectives 4 and 5. Three tasks are implemented to achieve this:
- conducting accelerated degradation experiments without modifying operating conditions on near-single-cell stacks,
- conducting accelerated degradation experiments with operating condition control strategies on near-single-cell stacks,
- repeating tests on stacks of around one hundred cells.
- The objective is to perform experiments on the European partner’s test benches to validate the proposals from objectives 4 and 5. Three tasks are implemented to achieve this:
The OPUS-H2 project : « Optimization of Performance and Durability of Hydrogen Systems using an Advanced Digital Twin » aims to promote the sustainable development of hydrogen systems and the energy transition toward a low-carbon economy. This will strengthen energy security in territories while reducing their dependence on imported energy resources. Knowledge sharing and cross-disciplinary expertise within the European Union network, combined with regional initiatives, will foster innovation and research in this field. The project’s outcomes (open-access digital twin and control strategies) will benefit all stakeholders in the energy transition (research institutes, industries, economic actors, etc.).
From a scientific perspective, the project will first provide the scientific community with an open-source fuel cell simulator, specialized for control applications—something not currently available at such an advanced level in the literature. Next, it will deepen the understanding of the relationship between voltage drop at high currents, liquid water content in the cell, and operating conditions through theoretical developments and experimental testing. Following this, control strategies to improve fuel cell performance will be experimentally validated. Additionally, the project will integrate and experimentally test cell degradation physics into the simulator to develop a model accounting for fuel cell aging. Resulting control strategies to extend fuel cell lifespan will then be experimentally assessed. Finally, the project will enable the candidate to acquire technical expertise on modern hydrogen test benches from the European partner, allowing these skills to be transferred to Réunion Island.
Funding partners
The OPUS-H2 project is funded by the European Union under the FEDER-FSE+ Réunion program, with the Réunion Region acting as the managing authority. Through the FEDER fund, Europe is committed to supporting Réunion.
Academic partners
The OPUS-H2 project aims to sustainably connect Réunion Island to the European research ecosystem by promoting interoperability and collaboration. Its main objective is to establish strong links to fully integrate the island into the European network. To this end, a new partnership has been formed with the ZSW research center (The Centre for Solar Energy and Hydrogen Research Baden-Württemberg) in Ulm, Germany. This laboratory is one of the most significant in the European Union for fuel cell modeling and testing on experimental benches.
- Project Coordinator:
- Scientific Manager for Energy-Lab:
- Associated professors at Energy-Lab: