Green Hydrogen as a Potential Solution for Reducing Carbon Emissions: A Review

Abstract

Hydrogen is one of the types of energy discovered in recent decades, which is based on the electrolysis of water in order to separate hydrogen from oxygen. These include grey hydrogen, black hydrogen, blue hydrogen, yellow hydrogen, turquoise hydrogen, and green hydrogen. Generally, hydrogen can be extracted from a variety of sources, including fossil fuels and biomass, water, or a combination of the two.  Green hydrogen has the potential to be a critical enabler of the global transition to sustainable energy and zero-emissions economies. Worldwide, there is unprecedented momentum to realize hydrogen's long-standing potential as a clean energy solution. Green hydrogen is a carbon-free fuel and the source of its production is water, and the production processes witness the separation of its molecules from its oxygen counterpart in the water by electricity generated from renewable energy sources such as wind and solar energy. Green hydrogen is one of the most important sources of clean energy, which may be why it is called green hydrogen. It is a clean source of energy, and its generation is based on renewable energy sources, so no carbon gases are released during its production. Green hydrogen produced by water electrolysis becomes a promising and tangible solution for the storage of excess energy for power generation and grid balancing, as well as the production of decarbonized fuel for transportation, heating, and other applications, as we shift away from fossil fuels and toward renewable energies. Green hydrogen is being produced in countries all over the world because it is one of the solutions to reducing carbon emissions, and it is clean, environmentally friendly energy that is derived from clean renewable energy. However, due to the combination of renewable generation and low-carbon fuels, projects for the production of green hydrogen are very expensive. The goal of this review is to highlight the various types of hydrogen, with a focus on the more practical green hydrogen.