Techno-economic assessment of Green Hydrogen Production for Blending in the Natural Gas Network

Increased electricity generation from renewable sources is critical for the transition towards a zero-carbon future. While this growth of production presents challenges in grid management due to inadequate storage systems for surplus electricity, solutions such as green hydrogen production offer promising avenues for integration into existing infrastructure. By leveraging surplus renewable electricity to power electrolyzers and inject green hydrogen into natural gas networks, we take a significant step forward in realizing an integrated gas-electric system. This study delves into this concept by conducting a comprehensive techno-economic assessment of a hydrogen production facility. The initial step is to determine the required volume of hydrogen to achieve a 10% concentration within a real natural gas distribution network. This value is such that the gas mixture remains within the Higher Heating Value (HHV), Wobbe Index (WI) ranges defined by Italian legislation. The goal is to optimize component sizing using a genetic algorithm to minimize the Levelized Cost of Hydrogen (LCOH) while meeting criteria for green hydrogen production. In fact, results show that an input from electricity grid is necessary to meet the hydrogen demand while maintaining the techno-economic feasibility of the system. A sizing optimization is therefore performed on photovoltaic, electrolyzer and storage system. Furthermore, the study underscores the critical role of energy policies, particularly green hydrogen incentives, in determining the economic feasibility of the system. By analyzing their impact on economic revenues, the authors emphasize the importance of supportive regulatory frameworks in driving the transition towards a more sustainable future.