High-pressure PEM water electrolyser: A review on challenges and mitigation strategies towards green and low-cost hydrogen production

There is unanimous agreement that the total power consumption for high-pressure PEM electrolysers without gas compressors is significantly lower than the total power consumption for atmospheric PEM electrolysers coupled with gas compressors; thus, low green hydrogen production costs are anticipated. However, significant bottlenecks to further lowering production costs through electrolysis are hampered by technological gaps in the development of high-pressure PEM electrolysers up to 350 bar or 700 bar. While 30–40 bar PEM electrolysers have been widely commercialised, only one 700 bar PEM electrolyser is on the market. Research and development for enhancing the stack components of high-pressure PEM electrolysers are advancing, but the translation into an actual product is sluggish. The present review aims to present the prevailing challenges and recent advancements of high-pressure PEM electrolysers towards a green and cheap hydrogen production cost. In addition to the fundamental aspect of PEM electrolysers, this review provides a market survey on the updated commercialised high-pressure PEM electrolysers. This review also highlights the prevailing challenges in high-pressure PEM water electrolysers and their recent advancements or possible mitigation strategies associated with operational challenges, coupling with renewable energy sources, and decoupling with gas compressors. A review of the techno-economic feasibility study of high-pressure PEM water electrolysers and their future projection is also comprehensively discussed. Finally, the possible pathways for driving cost-effective green hydrogen production based on the present and future state of art are also proposed to introduce cheaper green hydrogen.