Operational Scenarios in the Crete-Aegean Hydrogen Valley: Impacts of Hydrogen Demand and Infrastructure Design

In the realm of decarbonization and clean technologies, whose future development will affect the evolution of the energy systems known today, green hydrogen is becoming a major contributor. It can be produced through the electrolysis process from water, exploiting green electricity from renewable energy sources to avoid GHG emissions. The aim of this study is to analyze the development of the Crete-Aegean Hydrogen Valley, known as the CRAVE-H2 project, where most aspects of the supply chain of green hydrogen are addressed. Located on the island of Crete, its strategic position allows the exploitation of electric and gas network connections between the European and African continents, as well as the favourable Mediterranean weather supplying high RES electricity production. With an electrolysis capacity of 4MW, the Crete-Aegean Hydrogen Valley is expected to produce 500 tons of green hydrogen per year, which will progressively increase to contribute to the supply of the transport and maritime sector as well as European industries. As multiple components are involved in the plant, it is fundamental to understand their functioning and interactions in a real setting. To achieve this goal, a model of the valley has been created exploiting PyPSA - Python for Power System Analysis, which allows a more intuitive representation of all components. The model facilitates the optimization of the valley operation, through an annual simulation with hourly timesteps which aims at minimizing the total costs of the plant. The system is analysed in increasing hydrogen demand scenarios, assuming a progressive integration of hydrogen in the energy system surrounding the hydrogen valley. The results show a strong dependency of the electrolyser operation on the RES availability, which causes a low electrolyser load factor and indicates the importance of precise sizing of the components. Moreover, despite the requirements for green hydrogen production, grid support results to be fundamental to avoid RES plant oversizing, suggesting the need for a BESS system to further optimize RES production. Downstream hydrogen storage turns out to be fundamental for reliable load supply, stabilizing hydrogen production through an optimized operational strategy. The model proves valuable as a decision support tool, helping optimize both design choices and operations throughout the valley. Its adaptable nature makes it possible to evaluate different scenarios and examine key components in detail, allowing future adjustments to meet the specific needs of different case studies.