Among the different shades of hydrogen, GREEN HYDROGEN (GH) – meaning hydrogen produced from renewable energy – is the most suitable one for a fully sustainable energy transition. It is this shade that has been in the news lately as USA promised to use renewable energy to produce green hydrogen that costs less than natural gas. The Department of Energy is putting up to $100 million into the research and development of hydrogen and fuel cells. The European Union has a strategic plan for the transition to green hydrogen, with a view to decarburisation and climate neutrality in the future and will invest $430 billion in green hydrogen by 2030 to help achieve the goals of its Green Deal. And Chile, Japan, Germany, Saudi Arabia, and Australia are all making major investments into green hydrogen, A review on how Green hydrogen, an alternative fuel generated with clean energy, is experiencing a global resurgence and has been identified as the clean energy source that could help bring the world to net-zero emissions in the coming decades.