Policy-driven pathways to decouple China's hydrogen expansion from carbon lock-in

Hydrogen is pivotal for deep decarbonization, yet current production pathways in China risks entrenching carbon lock-in, as cost-competitive gray hydrogen dominates the market while green alternatives face prohibitive cost barriers and inadequate policy frameworks. To disentangle this paradox, we develop a bottom-up Hydrogen Production Pathway Planning Model (HPPPM) that integrates carbon pricing and subsidy mechanisms to systematically evaluate how targeted policy interventions reconfigure technology adoption, emission trajectories, and navigate systemic trade-offs. Key findings reveal: 1) Under current policies, gray hydrogen production is projected at 21.61 Mt by 2060, generating cumulative emissions of 20,500 Mt (equivalent to 50 % of 2024 global emissions). 2) The carbon pricing mechanism and the unit green hydrogen product subsidy can effectively drive the hydrogen production sector toward net-zero emissions, with the latter offering the lowest cost per unit of emission reduction. However, these incentives may lead to technological lock-in. 3) The initial investment subsidy has a modest direct impact on system emission reductions, but it can stimulate the development of capital-intensive technologies and effectively break the technological lock-in effect. Our research underscores the pivotal role of policy incentives in shaping hydrogen production technology selection and decarbonization pathways, providing critical insights for fossil fuel-dependent countries, particularly developing nations, on formulating cost-effective emission reduction policies.