Deployment of China's hydrogen production with loose or tight carbon-reduction paths

Hydrogen is likely to play an important role in achieving China's carbon neutrality target which is crucial for coping with the global climate change. Given that different regions of China are heterogeneous in terms of resources and demand, this study developed a provincial-level China energy system optimization model that considers ultra-high voltage (UHV) electricity transmission and hydrogen pipeline transmission among provinces. With the model, we evaluated the optimal deployment of hydrogen in China under two paths to be carbon-neutral: a relatively loose path for the 2 °C Global Temperature Target and a relatively tight path for the 1.5 °C Global Temperature Target. This study found that the tight path indicates a faster substitution of blue and green hydrogen for gray hydrogen, which is associated with the relocation of hydrogen production from coal-rich provinces to renewable-rich ones. Compared with the loose path, the tight path would require approximately 100 %–120 % higher annual investment in China from 2025 to 2035. This study also revealed that both the paths would increase the inter-provincial carbon emission transfer from developed to less-developed provinces. A policy implication is that China should consider implementing carbon accounting at the demand side, which would be vital for an equitable regional development.