Hydrogen energy is a secondary energy source with abundant sources and a wide range of applications. The utilization of hydrogen energy includes storing primary energy sources such as water, wind, and solar energy in the form of hydrogen, generating electricity through fuel cells to meet the demand for power supply, utilizing renewable energy across regions and seasons, and complementing green energy generation. It can be widely applied in fields such as energy, transportation, industry, and construction. It can directly provide efficient raw materials, reducing agents, and high-quality heat sources for industries such as refining, steel, and metallurgy, effectively reducing carbon emissions; Fuel cell technology can also be applied to fields such as automobiles, rail transit, and ships to reduce the dependence on oil and natural gas for long-distance and high load transportation; It can also be applied to distributed power generation, providing power and heating for residential and commercial buildings.

Hydrogen energy is clean and low-carbon, and is an important way to achieve carbon neutrality goals. Hydrogen energy has gradually become one of the important carriers for global energy transformation and development. It is also an important way to promote China's energy production and consumption revolution, build a clean, low-carbon, safe and efficient energy system, and achieve the goals of "carbon peak and carbon neutrality". According to the International Energy Agency, by 2050, hydrogen energy will meet 18% of the world's terminal energy demand. Countries such as Europe, the United States, Japan, and South Korea have identified hydrogen energy as an important direction for energy technology revolution and an important component of future energy strategic reserves.

Hydrogen energy is mainly divided into three types: gray hydrogen, blue hydrogen, and green hydrogen. Gray hydrogen is produced through the conversion reaction of fossil fuels (natural gas, coal, etc.) to produce hydrogen gas. Due to its low production cost and mature technology, it is currently a common method of hydrogen production. Due to the release of a certain amount of carbon dioxide during the hydrogen production process, it cannot fully achieve carbon free green production, hence it is called grey hydrogen; Blue hydrogen is the application of carbon capture, storage, and other technologies on the basis of grey hydrogen to preserve carbon, rather than releasing it into the atmosphere. Blue hydrogen, as a transitional technology, can accelerate the development of a green hydrogen society; Green hydrogen is produced by electrolyzing water through renewable energy sources such as photovoltaics and wind power. During the hydrogen production process, there will be minimal greenhouse gas emissions, hence it is known as "zero carbon hydrogen". Green hydrogen is an ideal form of hydrogen energy utilization, but it is currently limited by technological barriers and high costs, and it will take time to achieve large-scale application.

Green hydrogen is an important path to achieving carbon neutrality, and the potential for hydrogen production through renewable energy electrolysis of water is enormous. To achieve "carbon peak and carbon neutrality", China requires accelerating the application of green hydrogen and renewable energy, and promoting carbon reduction projects for electrolytic hydrogen production from renewable energy. From the perspective of technological paths, renewable energy electrolysis for hydrogen production, CCUS fossil energy for hydrogen production, and biomass for hydrogen production are the three low-carbon hydrogen production technology choices for the future. From the perspective of global ongoing or planned projects, hydrogen production based on low-carbon hydrogen production technology will continue to grow rapidly before 2030, and by 2050, 51% of global hydrogen production will be provided by renewable energy electrolysis water hydrogen production technology. Therefore, renewable energy electrolysis of water for hydrogen production is considered a promising hydrogen production technology in the future.