The application of energy storage technology in the field of electricity can be divided into three directions: generation side, transmission and distribution side, and user side. With the continuous development of the electricity market and the continuous innovation of energy storage technology in application models, the boundaries of the three directions are gradually becoming blurred. In summary, the application of electrochemical energy storage systems in the field of power generation mainly includes three directions, namely large-scale new energy grid connection, power auxiliary services, and microgrids. Here is a detailed explanation of these three aspects:

1、Large scale integration of new energy into the grid：In recent years, China's power industry has gradually developed towards low-carbon direction, and new energy generation has experienced rapid development, with wind and photovoltaic power generation rates continuously increasing. However, the volatility of new energy has an undeniable impact on the safety and stability of the power grid. Some regions have put forward strict requirements for the grid connection indicators of new energy, and if they fail to meet the requirements, they will face assessment, which will affect economic benefits. Therefore, exploring an effective and win-win combination model between energy storage and new energy generation is currently a research hotspot. Large scale energy storage can also achieve the functions of wind and solar energy recycling, and to some extent, recover the electricity lost by owners under power restrictions. Therefore, the application of energy storage technology in large-scale new energy grid integration can improve the stability of power grid system operation and improve the quality of incoming electricity while ensuring the penetration rate of new energy. Compared to other fields, energy storage needs to meet some special requirements in the application of new energy grid connection: the energy storage system needs to meet the characteristics of flexible configuration, easy installation, and long service life, in order to reduce the construction cycle and minimize maintenance or maintenance free as much as possible; In addition, new energy power stations have high environmental requirements, and energy storage batteries and devices should be selected with green and pollution-free characteristics as much as possible. At present, the main technical means in this application field include lithium iron phosphate batteries, lead carbon batteries, etc.

2、Power auxiliary services: With the increasing proportion of new energy generation in the power grid, in order to stabilize highly volatile wind or photovoltaic power sources, corresponding backup power capacity must be configured in the power grid. In order to improve the safety and quality of electricity, ensure the stability of the electricity market, it is also required that fast response power sources such as energy storage participate in the electricity auxiliary service market. The types of auxiliary services mainly include peak shaving frequency regulation, reactive power compensation, etc. Currently, more mature applications include peak shaving of pumped storage power stations and joint frequency regulation of lithium battery thermal power. Recently, State Grid of China has successively planned multiple hundred megawatt level energy storage projects in Jiangsu, Henan, Hunan and other places, effectively supporting the stable operation of the power grid, and the market for auxiliary services on the power generation side is becoming saturated.

3、Microgrid：Microgrid mainly includes distributed energy, AC/DC loads, energy storage, power transformation and distribution, and control systems. Local power generation resources can be fully utilized to achieve spontaneous self use, and surplus power can be connected to the grid. The role of energy storage in microgrids mainly includes two aspects: (1) improving the stability and power quality of microgrids: energy storage systems can provide fast power buffering, absorb/supplement energy, provide active and reactive power support, and stabilize voltage fluctuations. Energy storage equipment, as a key part of energy storage and regulation, is controlled through an Energy Management System (EMS) to coordinate distributed power sources with energy storage systems and the main power grid, ensuring stable output. Helps improve the reliability and efficiency of the system. (2) Peak valley electricity price arbitrage: Utilizing energy storage systems for peak valley difference arbitrage refers to the profit model of charging and storing electricity during low electricity prices and supplying electricity to users during peak hours. At present, there are application cases in lead carbon batteries, lithium iron phosphate batteries, vanadium flow batteries, etc.

In summary, the continuous deepening of electricity market reform will promote the rapid development of energy storage technology to meet the increasing demand for applications; The advancement of energy storage technology will also drive changes in the form of the power industry, exerting greater practical value in the application of power generation, and generating considerable economic benefits.