Life-Cycle Environmental and Economic Assessment of Photovoltaic and Grid-Powered Green Hydrogen Chains in Northwest China

This study conducts a cradle-to-gate life-cycle environmental and economic assessment of industrial-scale hydrogen production in the Yumen Oilfield, Northwest China. Eight scenarios are established by combining photovoltaic (PV) or grid electricity, alkaline water electrolysis (AWE) or proton exchange membrane electrolysis (PEM), and pipeline or tube-trailer transportation over 100 km. Global warming potential (GWP), acidification potential (AP), metal depletion (MD), water consumption, and the levelized cost of hydrogen (LCOH) are evaluated. The results show that the electricity source is the dominant factor affecting the environmental performance. Compared with grid-powered scenarios, PV-powered hydrogen reduces GWP by up to 91% and water consumption by approximately 87%, although it increases MD because of the material requirements of PV infrastructure and, particularly for PEM-based pathways, electrolyzer stack manufacturing. Contribution analysis reveals that hard coal dominates grid-related GWP and AP, whereas hydropower is the primary contributor to grid-related water consumption. In PV-powered scenarios, truck transportation contributes significantly to the GWP and AP, indicating that downstream compression and transportation should not be neglected in industrial hydrogen supply chains. An integrated environmental-economic assessment shows that PV-powered hydrogen achieves a better balance between carbon reduction and cost performance than grid-powered hydrogen. Under the specific carbon-price and slow, medium, and fast development assumptions, PV-powered hydrogen is projected to approach or enter the cost range of gray hydrogen by 2035.