Lithium-ion batteries for energy storage mainly refer to lithium-ion battery packs used in solar power generation equipment, wind power generation equipment, and renewable energy storage. Currently, energy storage batteries are used in various scenarios such as renewable energy grid connection, grid ancillary services, grid transmission and distribution, distributed generation and microgrids, and user-side energy storage.
1. Renewable energy grid connection
In recent years, in order to utilize more renewable energy sources and improve the reliability and efficiency of power grid operation, research and engineering demonstration projects on various energy storage technologies have developed rapidly. Large-capacity battery energy storage technology, applied to wind and solar power generation, can smooth power output fluctuations, reduce their impact on the power system, improve the ability of power plants to track planned output, and provide backup energy for the construction and operation of renewable energy power plants.
2. Power Grid Ancillary Services
Grid ancillary services are divided into capacity-based and power-based services. Capacity-based services include grid peak shaving, load following, and black start. Energy storage battery technology can improve grid frequency regulation capabilities by reducing losses caused by frequent switching in traditional frequency regulation power sources. In terms of enhancing grid peak shaving capabilities, energy storage systems can respond promptly and reliably to dispatch commands based on changes in power supply and load, and adjust their output levels accordingly.
3. Power grid transmission and distribution
Energy storage battery systems can improve power distribution quality and reliability. When a distribution network fails, they can serve as a backup power source to continuously supply power to users. In terms of improving power quality, they act as a controllable power source to manage the power quality of the distribution network, eliminating problems such as voltage dips and harmonics, while reducing the investment in backbone network expansion and saving expansion funds.
4. Distributed networks and microgrids
Microgrid systems are required to be equipped with energy storage devices, and the energy storage devices are required to be able to: (1) provide short-term uninterrupted power supply when the grid is off-grid and distributed power sources cannot supply power; (2) meet the peak shaving needs of the microgrid; (3) improve the power quality of the microgrid; (4) complete the black start of the microgrid system; (5) balance the output of intermittent and fluctuating power sources and effectively control the electrical load and thermal load.
Energy storage battery systems have the characteristics of dynamically absorbing and releasing energy as needed. As an essential energy buffer for microgrids, they can improve power quality, stabilize grid operation, optimize system configuration, and ensure the safe and stable operation of microgrids.
5. User side
User-side energy storage mainly includes peak shaving and valley filling for industrial and commercial users, as well as demand-side response. Batteries combined with power electronics technology can provide users with reliable power, improve power quality, and save costs by utilizing the price difference between peak and off-peak electricity rates.
6. Energy supply system for VEG mode of electric vehicles
The development of the new energy vehicle industry must be coordinated with the energy storage industry. In order to meet the future demand for safe and fast charging of electric vehicles, it is necessary to establish distributed energy stations similar to gas stations. These energy stations are equipped with low-cost, long-life megawatt-level energy storage batteries, which can charge and store electricity from the grid to quickly charge electric vehicles. At the same time, the energy stations can also interact with the grid for peak shaving or frequency regulation.
