This project focuses on the design, control, and energy management of an offshore MVDC grid dedicated to green hydrogen production. The proposed MVDC grid integrates renewable energy sources (e.g., offshore wind turbines), electrolyzer stacks, and a hybrid supercapacitor–battery storage system. Each unit will be interfaced with the DC bus through modular power electronic converters.
A decentralized, multi-agent control system will be developed to coordinate the operation of electrolyzer stacks and energy storage units. This approach aims to minimize the levelized cost of hydrogen (LCOH) while mitigating electrolyzer cell degradation. Optimal energy management strategies, enhanced by wind and solar forecasting, will be implemented to maximize efficiency and system reliability.
The project will also develop prototype business models for the novel hybrid energy storage system. Significant cost reductions are expected through the use of hybrid battery/supercapacitor storage combined with innovative, application-tailored, low-cost supercapacitor technology.
The proposal primarily addresses the second main area of the call (Operation, Control, and Protection) while also contributing to the third area, Verification, Testing, and Maintenance. The integration of optimal control and energy management of hybrid storage, combined with intelligent coordination of modular and parallel electrolyzer stacks, will improve the flexibility and stability of the islanded MVDC grid. Moreover, it will extend electrolyzer lifetime by reducing load fluctuations.
Finally, the decentralization of both hardware (via modular power electronics and modular stacks) and software (through distributed control and energy management) will enhance the reliability, scalability, and resilience of the offshore MVDC grid.
The OptiDCG4H2 project is a pioneering initiative aimed at advancing offshore green hydrogen systems to align with the ambitious objectives outlined in the European Green Deal. Green hydrogen is a key player in the green energy transition. With the overarching goal of achieving a competitive and climate-neutral EU economy in 2025, OptiDCG4H2 focuses on developing an innovative and reliable hydrogen system that adds flexibility to renewable energy sources (RESs), such as offshore wind farms. One of the most important business cases for green hydrogen production is an energy island. Here, the integration of electrolyzers with offshore wind farms in these systems facilitates low-cost green hydrogen production. By converting to off-grid operation, substantial cost reduction is attained through the elimination of the electrical network between the offshore wind farm and the onshore grid. However, the intermittency of wind power gives rise to variations in the electrolyzer’s input power with oscillations of various periods (seconds, minutes, and hours). Those variations degrade the electrolyzer stack and reduce its lifetime, hence the overall system reliability will deteriorate. This issue is especially prominent in offshore applications, where maintenance is costly. Moreover, the stability of such an islanded system can be jeopardized if the rate of change of wind power exceeds the ramp rate of the electrolyzer. Additionally, the utilization factor of electrolyzer can be quite low, which increases the capital expenditure (CAPEX) per unit of hydrogen production. To cope with these fundamental problems, the OptiDCG4H2 project advances the islanded hydrogen system by including an energy storage system that works as an energy buffer between the wind turbine generators and the electrolyzers. The storage system smooths out power fluctuations on the electrolyzer, hence preventing fast degradation of electrolyzer cells.
