Life Cycle Sustainability and Techno-Economic Trade-offs of Hydrogen from PEM Electrolysis: A Comparative Study of Power Sources

Hydrogen energy is vital for future clean energy systems, and its production methods critically influence environmental sustainability and economic viability. Unlike previous studies that focus on either environmental or economic aspects, this study develops an integrated life cycle assessment (LCA) and techno-economic analysis (TEA) framework under a unified functional unit to systematically evaluate PEM electrolytic hydrogen production powered by coal, photovoltaic (PV), and wind power. The results indicated that coal-based hydrogen had significantly higher global warming potential (GWP: 22.03 kg CO2-eq/kg H2) and acidification potential (AP: 0.25 kg SO2-eq/kg H2) than renewable options. PV and wind pathways greatly reduced GWP (2.98 and 1.80 kg CO2-eq/kg H2, respectively) but shift the environmental burden toward abiotic depletion potential due to electrolyzer manufacturing (ADP: 1.64 × 10–4 and 6.27 × 10–5 kg Sb-eq/kg H2, respectively). A key finding is that the dominant contributors to environmental impacts differ fundamentally across power sources: electricity generation governs impacts in coal-based systems, whereas electrolyzer manufacturing becomes the primary hotspot in renewable-powered systems. TEA revealed that coal-based hydrogen had the lowest levelized cost (¥10.57/kg H2), highlighting a trade-off between economic feasibility and environmental performance. By jointly considering environmental impacts, economic costs, and resource depletion, this study provides new insights into the complementary roles of PV and wind power and highlights the importance of balancing sustainability and system stability in advancing green hydrogen pathways.