At present, an important issue facing the transformation of the energy system is to improve the flexibility of the energy system, enhance energy regulation capabilities, and solve the problems of renewable energy consumption and supply-demand matching.

The "flexibility" and "fuel/raw material properties" of hydrogen energy perfectly match the flexibility and deep decarbonization issues faced by the energy system in the process of supply and demand transformation. This is the fundamental reason why hydrogen energy has become an important component of the future energy system.

Hydrogen energy is a high-quality resource that supplements the flexibility of energy systems

Electricity is a "rigid" energy source that is difficult to store directly and needs to be converted into other forms of energy, which requires real-time consistency between power generation and consumption. Unlike electricity, hydrogen energy has temporal flexibility in its preparation and use. Due to its ease of storage and the fact that hydrogen production and use do not need to be carried out simultaneously, hydrogen can be considered a flexible energy source. With the rapid development of renewable energy, the power system has gradually shifted from being "adjustable on the power side and uncontrollable on the load side" to "uncontrollable on both the power and load sides", increasing the difficulty of real-time balancing supply and demand in the power system. Therefore, hydrogen energy, as a flexible energy source that can be produced from electricity and does not emit waste during use, can be well integrated into the future renewable energy system dominated by electricity, providing regulatory capabilities for the power system.

Energy storage solutions can be mainly divided into several categories: thermal energy storage, mechanical energy storage, electrochemical energy storage, electromagnetic energy storage, and chemical energy storage. Among them, pumped storage is currently the most important traditional energy storage method, accounting for 77% of China's total installed energy storage capacity; In the new energy storage, lithium-ion batteries are currently the most important solution, accounting for about 94% of the installed capacity of new energy storage.

Under the current energy storage scheme, there will still be a significant gap in renewable energy power regulation in the future. These gaps mainly come from three aspects. Firstly, due to the limitations of carbon neutrality targets, the scale of flexible coal-fired and natural gas power generation units as fossil fuel power generation methods is restricted. Secondly, due to geographical limitations and other factors, the development scale of pumped storage also has a certain upper limit. Thirdly, although electrochemical energy storage is a rapidly developing new energy storage method, it still faces issues such as lithium resource constraints, high costs, and safety in the application of long-term and large-scale energy storage needs.

According to the current situation, the power regulation gap of renewable energy will reach 1200GW by 2030; by 2050, this gap will exceed 2500GW. Therefore, in order to meet the needs of energy transformation, new energy storage methods need to be introduced in the future to develop renewable energy systems.

Hydrogen energy can provide flexibility for the power supply side, grid side, and load side of the power system. On the power side, by combining with wind and solar energy, on-site hydrogen production can be achieved and excess renewable energy can be consumed, thereby reducing power generation fluctuations. On the grid side, by combining electrolytic hydrogen production with hydrogen energy generation, the peak and valley loads of the grid can be adjusted through hydrogen storage. On the load side, hydrogen production/consumption scenarios such as electrolysis water hydrogen production and hydrogenation integrated stations can selectively produce hydrogen according to the high or low electricity price to meet the demand side response.