The integration of renewable energy sources, particularly photovoltaic (PV) solar, is increasingly challenged by the limited flexibility and storage capacity of existing ener-gy systems. Hydrogen produced via renewable-powered electrolysis offers a promising pathway to address these constraints. Among the various utilization options, hydrogen injection into natural gas grids represents a technically feasible and strategically rele-vant solution in the medium term. The paper develops a methodological framework aimed at interpreting hydrogen injection as a flexibility option for renewable energy integration and storage. The approach focuses on identifying those gas network seg-ments where flow fluctuations are minimal, conditions more suitable for hydrogen blending, and on quantifying the potential contribution of this strategy to PV expan-sion. The methodology is applied to the Italian energy system, a paradigmatic case characterized by strong PV growth and extensive natural gas utilization. Results indi-cate that, under current regulatory constraints (up to 5% hydrogen blending), the ad-ditional PV capacity that could be effectively integrated remains limited, and the overall decarbonization impact modest. Nonetheless, the analysis highlights the con-ceptual and methodological value of considering gas networks as dynamic compo-nents of an integrated energy system. In this perspective, hydrogen injection emerges less as an immediate large-scale solution and more as a framework for coupling power and gas systems, paving the way for future assessments under evolving technical, economic, and regulatory conditions.
Franco et al. (Thu,) studied this question.