Advancing the green hydrogen economy: A techno‑economic and environmental assessment

Hydrogen is widely seen as the one energy carrier that could afford deep decarbonisation. However, hydrogen's climate and economic performance, depending on various production routes, system boundaries, and infrastructure contexts, are highly variable. A harmonised, multi-criteria assessment is discussed, integrating techno-economic performance, lifecycle carbon intensity, technology readiness, and storage compatibility across 7 major hydrogen production pathways under consistent analytical assumptions. Results indicated that a small number of system-level thresholds determine competitiveness. Electrolysis becomes cost-competitive with fossil-based hydrogen when electricity prices fall to about 30–40 USD/MWh. In contrast, blue hydrogen keeps lifecycle emissions below approximately 3 kg CO₂/kg H₂ only at very high capture rates and a reliable containment of methane leakage. Biomass gasification coupled with carbon capture emerges as the only scalable route to net-negative hydrogen, constrained primarily by sustainable feedstock availability. Storage analysis identifies geological formations as the only viable option for long-duration, system-scale balancing of variable renewable energy. By linking production, storage, cost structure, emissions, and maturity within a unified framework, this study moves beyond technology comparison to identify deployment-ready hydrogen strategies for different resource and infrastructure contexts. The findings provide decision-relevant guidance for policy, industrial clusters, and regional hydrogen scale-up in the 2020–2035 period.