Assessment of the provincial hydrogen potential through photovoltaic generation in China from the perspective of water resources limits

Green hydrogen production through photovoltaic-driven water electrolysis is one of the most essential strategies for decarbonization in the 21st century due to its production process. Water resources are an indispensable factor in this electrolysis process, especially with the large-scale development of photovoltaic hydrogen (PVH) production. Therefore, it's necessary to assess the PVH potential by incorporating land suitability and water sustainability. However, previous studies didn't quantify the impact of water limits on PVH scale production. This study establishes a provincial-scale framework integrating technical potential, land suitability, and water sustainability to assess hydrogen technical potential through photovoltaic-driven water electrolysis and proposes a PVH resource potential index considering water resource limits. High-resolution ERA5-Land datasets (1-h temporal, 10 km spatial resolution) were utilized to model hourly solar radiation and temperature, while Geographic Information System (GIS) - based methods were employed to assess land suitability using geospatial indicators (temperature, transportation networks) and water resource constraints. Key findings reveal a distinct distribution pattern of technical potential, characterized by northwestern regions > coastal areas > inland regions. Seventeen provinces may experience water scarcity by 2060. Furthermore, large-scale PVH deployment would exacerbate such water shortages. Under this scenario, the resource potential drops to 1.92 × 108 per year – representing an 82 % reduction compared to the technical potential. Spatial mismatches between land suitability and resource potential are identified, with high-potential western regions exhibiting lower suitability scores. This framework provides actionable insights for prioritizing photovoltaic generation-to‑hydrogen systems deployment in national-level high-potential regions and optimizing cross-provincial resource management.