A perspective on three sustainable hydrogen production technologies with a focus on technology readiness level, cost of production and life cycle environmental impacts

Hydrogen will play an indispensable role as both an energy vector and as a molecule in essential products in the transition to climate neutrality. However, the optimal sustainable hydrogen production system is not definitive due to challenges in energy conversion efficiency, economic cost, and associated marginal abatement cost. This review summarises and contrasts different sustainable hydrogen production technologies including for their development, potential for improvement, barriers to large-scale industrial application, capital and operating cost, and life-cycle environmental impact. Polymer electrolyte membrane water electrolysis technology shows significant potential for large-scale application in the near-term, with a higher technology readiness level (expected to be 9 by 2030) and a levelized cost of hydrogen expected to be 4.15-6 €/kg H