Cost and technology readiness level assessment of emerging technologies, new perspectives, and future research directions in H production

There is a worldwide debate on the use of renewable energy resources and economically viable technologies for energy-efficient systems. Since H energy is the future of the world energy scheme, at the center of the discussion are the old existing methods of research and some new developments in emerging technologies. The few currently used H production technologies are outdated and not so competitive and this means a tight bottleneck in the overall energy system. Furthermore, expectations arise with the advancement of the world energy system to find the most innovative alternative renewable energy resources. This present review allows a better understanding of conventional technologies and recently emerging techniques for H production. This paper provides a brief introduction to some of the existing technologies/methods, advantages, and drawbacks. Furthermore, this work aims to show the new state-of-the-art emerging technologies and their benefits in the future energy system and a clear pathway to finding alternative schemes of energy with better working efficiencies. Most importantly, the maturity level of most fossil-based technologies and the new emerging technologies based on the timeline for their commercial availability is a part of this review. Cost and technology readiness level assessment of some of the old and new emerging technologies for unit H production in comparison with or concerning commercially available steam methane reforming technology has been summarized. Future perspectives and new research directions in H production technology have also been proposed for further research and development.