Energy storage power is a battery, and "energy storage" refers to the storage of energy by converting different forms of energy such as electrical energy, thermal energy, and mechanical energy into other forms of energy, and releasing them when needed. Batteries are the most common energy storage devices, but the "energy storage system" discussed in this article has higher technical complexity and larger scale. Generally speaking, energy storage systems can be divided into the following categories: pumped storage is currently the most mature and largest installed capacity energy storage technology, which uses electricity from low power loads to pump water to the upper reservoir and then discharge water to the lower reservoir for power generation during peak power loads. Pumped storage can provide various auxiliary services such as peak shaving, frequency regulation, and emergency backup for the power system.