Hydrogen valleys to foster local decarbonisation targets: a multiobjective optimisation approach for energy planning

Hydrogen Valley represents localised ecosystems that enable the integrated production, storage, distribution, and utilisation of hydrogen to support the decarbonisation of the energy system. However, planning such integrated systems necessitates a detailed evaluation of their interconnections with variable renewable generation, sector coupling, and system flexibility. The novelty of this work lies in addressing a critical gap in system-level modelling for Hydrogen Valleys by introducing an optimization-based framework to determine their optimal configuration. This study focuses on the scenario-based, multiobjective design of local hydrogen energy systems, considering renewable integration, infrastructure deployment, and sector coupling. We developed and simulated three scenarios based on varying hydrogen pathways and penetration levels using the EnergyPLAN model, implemented through a custom MATLAB Toolbox. Several decision variables, such as renewable energy capacity, electrolyser size, and hydrogen storage, were optimised to minimise CO₂ emissions, total annual system cost, and critical excess electricity production simultaneously. The findings show that Hydrogen Valley deployment can reduce CO₂ emissions by up to 30 %, triple renewable penetration in the primary energy supply, and lower the levelized cost of hydrogen from 7.6 €/kg to 5.6 €/kg, despite a moderate increase in the total cost of the system. The approach highlights the potential of sector coupling and Power-to-X technologies in enhancing system flexibility and supporting green hydrogen integration. The outcome of our research offers valuable insights for policymakers and planners seeking to align local hydrogen strategies with broader decarbonisation targets and regulatory frameworks.