Assessing the impact of subsidy policies on hydrogen production technology innovation: Evidence from international energy agency countries

Hydrogen production technology innovation is a key aspect to reducing the difficulty and cost of hydrogen production, which is crucial for promoting clean energy development. This study collects global hydrogen production patent data from 2000 to 2023 and constructs a multi-dimensional system to evaluate the value of these patents. Further, this study constructs a balanced panel dataset including International Energy Agency countries, and empirically examines the impact of hydrogen production subsidy policy (HPSP) on hydrogen production technology innovation, i.e., the value of hydrogen production patents, through the multi-period difference-in-differences model. We find that the number and value of water hydrogen production patents is growing very rapidly, and that China is leading the world in hydrogen production patents. The empirical results show that the implementation of HPSP leads to a significant 11.2% average increase in the total value of patents. The channels through which these positive effects occur are that HPSP increase hydrogen technology research and development budgets and significantly increase hydrogen production and carbon capture, utilization and storage projects. Moreover, the promotional effect of HPSP on hydrogen production technology innovation is enhanced by cross-country technological cooperation, the issuance of complementary policies, and infrastructure construction. Furthermore, in terms of policy types, the combined R&D and production policies yield the most significant innovation impact. The HPSP has a stronger impact on the innovation of hydrogen production technology from fossil energy and water, and it plays a greater role in developing countries. This study provides empirical evidence that HPSP promote hydrogen production technology innovation and emphasizes the need for global confidence and sustained policy support for hydrogen development.