The H2GridTwin project aims at developing a digital twin for a future hydrogen-to-grid living lab. The digital twin will enable advanced control strategies and optimal system operation to maximise local consumption of green energy.
The project is carried out within BRITE, such that the two official partners are Université libre de Bruxelles (ULB) and Vrije Universiteit Brussel (VUB)
This project is funded by the Belgian federal Energy Transition Funds (SPF/FOD Economie).
The project started in November 2023 and ended in October 2025.
Project description & goals
As the global energy transition advances toward carbon neutrality, renewable energy sources are expected to become the dominant component of the future energy mix. However, their intermittent nature, both daily and seasonal, poses significant challenges for balancing supply and demand. While short-term fluctuations can be managed using technologies such as batteries and hydraulic storage, long-term storage increasingly relies on the power-to-fuel paradigm. Among the various energy carriers, hydrogen has emerged as a promising solution due to its high energy density, versatility, and potential for integration across energy sectors. Nevertheless, hydrogen-based systems are often limited by low round-trip efficiency, primarily due to heat losses during reconversion to electricity. To improve overall system performance, integrated approaches that recover and utilise this thermal energy (particularly via district heating networks) are essential, especially in urban environments.
The H2GridTwin project aims to address these challenges by developing a comprehensive digital twin of a hydrogen-based multi-energy system. This digital twin enables advanced control and optimisation strategies, with the goal of maximising local renewable energy use and improving energy system efficiency. At the core of the project is the creation of Physics-Informed Reduced-Order Models (PI-ROMs) for each system component, which serve as the foundation for a real-time capable, integrated digital twin.
The figure below provides a schematic overview of the hydrogen energy system under consideration. Its main components and their attributions to the partners are highlighted.
Conclusions & outputs
Electrolyser (WP1)
A comprehensive multi-physics PEM electrolyser model was developed, coupling electrochemical, thermal, mass-transport, and degradation phenomena. To enable efficient control-oriented simulations, the degradation submodel was replaced with a neural-network surrogate, removing numerical stiffness while maintaining high accuracy. The resulting reduced-order model was successfully integrated into the MPC framework, which was tested under dynamic electricity price scenarios, confirming its ability to optimise electrolyser operation by balancing efficiency and lifetime. A journal article and a patent on these topics are currently under review.
Internal Combustion Engine (WP2)
A two-zone 0D hydrogen engine model was developed and validated against manufacturer data, showing good agreement. Furthermore, to enhance the model's predictive capability, a symbolic regression–based extension was added. This data-driven approach identified explicit functional relationships between key combustion parameters and operating conditions, enabling the model to predict engine behaviour under variable spark advance and equivalence ratio. The resulting grey-box model holds enhanced accuracy over a wide range of operating conditions, therefore ensuring reliability of prediction when the ICE is operated by the MPC algorithm.
Micro-Gas Turbine (WP3)
A steady-state reduced-order model of the Turbec T100 was derived from an existing detailed dynamic model. A parameter optimisation procedure was then performed to calibrate the model. Overall, the steady-state mGT ROM achieved high accuracy with reduced computational cost, making it suitable for integration into the global digital twin of the hydrogen living lab.
District Heating Network (WP4)
A dynamic model for the district heating network was developed. The model was able to capture heat transport delays and network inertia, which can be exploited by the MPC as an additional source of flexibility to buffer energy price fluctuations and improve overall system efficiency.
Global Digital Twin and MPC Integration (WP5)
All PI-ROMs were integrated into a single digital twin, representing the complete hydrogen-based multi-energy system, including hydrogen storage, battery arrays, and thermal storage subsystems. A bespoke MPC controller was developed to coordinate all components, minimising operating costs while satisfying technical and physical constraints. Case studies demonstrated the effectiveness of the overall control framework, resulting in cost reduction and improved plant operation.