Abstract:
There is significant popularity and interest in hydrogen energy from all sectors as one of the promising solutions for a sustainable energy storing method. Hydrogen is the most abundant element in the universe, which is available in many forms. Hydrogen is catagorized by colour codes and it is called green hydrogen when produced through electrolysis using renewable energy sources. These recent developments in green hydrogen have increased attention on aspects such as hydrogen production technologies, hydrogen colour codes, life cycle analysis, and challenges faced. The maritime industry, aviation sector, and transportation industry are some of the major industries that focus on hydrogen energy as an alternative green energy source. Hydrogen production using various renewable energy sources has become a promising way to utilise hydrogen, especially as an electrochemical energy storage medium, which can later be used as a carbon-neutral fuel for various applications. By highlighting the diverse colour codes of hydrogen, weighing both the positive and negative environmental impacts through life cycle analysis on various production technologies, and discussing the critical insights and future implications, this review provides a comprehensive overview of the hydrogen energy landscape. This distinctive approach not only enriches the existing literature but also deepens our understanding of hydrogen's potential as a promising energy source.