The world is witnessing increasing interest in developing clean and sustainable energy sources to reduce greenhouse gas emissions and dependence on fossil fuels. In this context, green hydrogen has emerged as a promising option in the field of clean energy because it can be produced using renewable energy sources and utilized in a wide range of industrial and economic applications. What Is Green Hydrogen? Green hydrogen is hydrogen produced using renewable energy sources, such as solar and wind power, through processes that do not rely on fossil fuels as the primary energy source. Water electrolysis is one of the main methods used for its production, in which electricity is used to split water into hydrogen and oxygen. The importance of this technology lies in its potential to produce hydrogen with low greenhouse gas emissions when renewable electricity is used. However, the overall environmental impact of production, transportation, and storage must also be considered. How Is Green Hydrogen Produced? Green hydrogen is primarily produced using a device known as an electrolyzer, which uses electrical energy to drive the chemical reaction that decomposes water molecules. The overall reaction for water electrolysis can be represented as follows: 2H₂O(l) → 2H₂(g) + O₂(g) During this process, water is decomposed to produce hydrogen gas at the cathode and oxygen gas at the anode. When the electricity is supplied by renewable sources, such as solar or wind power, hydrogen can be produced with a lower carbon footprint than conventional fossil-fuel-based methods. Applications of Green Hydrogen Green hydrogen has significant potential across several sectors. In the chemical industry, it can serve as a feedstock for producing ammonia and various chemical compounds. It may also help reduce emissions from certain industrial processes that are difficult to electrify directly. In the energy sector, hydrogen can be used to store renewable energy by converting surplus electricity into a fuel that can be utilized later. It can also be applied in some transportation systems, particularly fuel-cell vehicles, and in other sectors that require high energy density. Green Hydrogen and Environmental Protection One of the main advantages of green hydrogen is its potential to reduce carbon dioxide emissions associated with hydrogen production and use when it is produced from renewable sources and managed efficiently. When hydrogen is used in fuel cells, it reacts electrochemically with oxygen to generate electricity and water, without producing carbon dioxide from the electrochemical reaction itself. Nevertheless, the actual environmental benefits depend on the hydrogen production method, the energy source used, and the infrastructure required for transportation and storage. Challenges Facing Green Hydrogen Despite its potential benefits, green hydrogen faces several technical and economic challenges. These include relatively high production costs under certain conditions, the need for substantial amounts of renewable electricity and water, and difficulties associated with storage and transportation due to hydrogen’s low volumetric density and the need for specialized safety systems. Consequently, current research focuses on improving electrolyzer technologies, increasing production efficiency, reducing equipment costs, and developing safer and more effective methods for hydrogen storage and transportation. The Future of Green Hydrogen Advances in renewable energy technologies and water electrolysis are expected to expand the potential applications of green hydrogen. Collaboration among chemistry, engineering, and materials science can contribute to the development of more efficient catalysts, improved electrode materials, and more sustainable hydrogen production systems. Investment in scientific research and infrastructure development will be important in determining the extent to which green hydrogen can contribute to the global transition toward clean energy. Conclusion Green hydrogen represents a promising pathway toward sustainable energy systems because of its potential to reduce carbon emissions and support industries in which decarbonization is difficult to achieve through conventional methods. Although challenges related to production costs, efficiency, and storage remain, continued advances in chemical and engineering technologies may strengthen its role in building a more sustainable and energy-efficient future. Al-Mustaqbal University – The First University in Iraq