Assessing Transition Pathways of Hydrogen Production in China with a Probabilistic Framework.

The transition of China's hydrogen production system to meeting carbon neutrality is considerably uncertain. This study uses a probabilistic framework to assess the transition pathways of hydrogen production in China to meet the goal of carbon neutrality and reveals the key technology selection mechanism. Three strategies for hydrogen production transition were considered: delayed, orderly, and radical, corresponding to the green hydrogen shares between 70 and 95% in 2060. More ambitious strategies tended to result in greater uncertainty of green hydrogen production and introduce higher system costs and cost uncertainty. The different strategies showed notable differences in carbon dioxide (CO) reduction pathways. The cumulative CO emissions of the delayed strategy may reach 3 times that of the radical strategy, and the CO reduction uncertainty of the orderly strategy may be twice that of the other strategies. Alkaline electrolyzers were predicted to dominate green hydrogen production until being surpassed by proton exchange membrane electrolyzers (PEM) after 2060. The synergy of the solar-energy storage-PEM technology combination was notable because expensive electrolyzers tended to increase utilization, thereby diluting fixed costs. Our results underscore the importance of studying the impact of uncertainty and technology selection mechanisms on transition pathways.