Green hydrogen, often simply referred to as “green H2,” is a type of hydrogen produced through a process that uses renewable energy sources, primarily wind and solar power, to split water molecules into hydrogen and oxygen via a process called electrolysis. Unlike hydrogen produced from fossil fuels (gray hydrogen) or natural gas with carbon capture and storage (blue hydrogen), green hydrogen production generates no direct greenhouse gas emissions, making it a vital component of efforts to decarbonize various sectors of the economy.

The International Renewable Energy Agency (IRENA) published a report on Green Hydrogen in 2021, emphasizing the following key points:

1. Production Process: Green hydrogen is produced using electricity generated from renewable sources, typically wind or solar, to power electrolysis equipment. During this process, water (H2O) is split into hydrogen (H2) and oxygen (O2). The hydrogen can then be captured, stored, and transported for various applications.
2. Zero Emissions: The primary advantage of green hydrogen is its carbon neutrality. Since it is produced using renewable energy, the entire lifecycle of green hydrogen, from production to end-use, has minimal to zero greenhouse gas emissions. This characteristic makes it a crucial tool for decarbonizing sectors that are difficult to electrify directly, such as heavy industry and long-haul transportation.
3. Applications: Green hydrogen has a wide range of applications, including as a fuel for fuel cell vehicles (FCVs), feedstock for industrial processes (e.g., ammonia and steel production), and energy storage. It can also be used to produce synthetic fuels like e-methane or e-kerosene.
4. Energy Storage: Green hydrogen can serve as a form of energy storage, allowing excess renewable energy generated during periods of low demand to be converted into hydrogen. This hydrogen can then be stored and used later to produce electricity or provide energy for other applications when renewable energy generation is insufficient.
5. Challenges: While green hydrogen offers numerous advantages, there are challenges associated with its widespread adoption. These include the high upfront costs of electrolysis equipment, the need for further cost reductions to compete with other forms of hydrogen, and the development of infrastructure for hydrogen transportation and distribution.
6. Policy and Investment: Governments and industries are investing in the development of green hydrogen technologies. Policies, incentives, and funding mechanisms are being implemented to accelerate its deployment and scale production.
7. International Cooperation: International collaboration is critical to developing a global market for green hydrogen. Agreements and initiatives, such as the Green Hydrogen Catapult, aim to drive down costs and scale up green hydrogen production.

In summary, green hydrogen holds great promise as a clean energy carrier and a key enabler of the transition to a low-carbon economy. Its ability to store renewable energy and decarbonize hard-to-abate sectors makes it a valuable tool in addressing climate change and achieving energy sustainability goals. Continued research, development, and investment in green hydrogen technologies are essential to unlock its full potential.