The energy storage method used in a distributed power generation system mainly depends on the role of the energy storage unit in the system. Because different energy storage methods have different response characteristics, the energy storage method that can most reliably implement the function should be selected according to the function designed for the energy storage unit in the distributed power storage unit. Of course, when there are many energy storage methods that meet functional needs technically, further choices should be made according to economy.

The impact of distributed power sources on the system mainly depends on its penetrating power limit. According to some statistics from European countries, it is feasible to penetrate 10%. Or the grid is weak. It can be considered that the power of DG is completely absorbed by the power grid, but energy storage can play an important role of calming system disturbance, maintaining power generation/load dynamic balance, and maintaining voltage/frequency stability. To achieve the purpose of maintaining the dynamic balance of power generation/load, energy storage must have a large capacity/power throughput ability. In order to keep the system voltage/frequency stable, energy storage must have millisecond response speed and a certain capacity power compensation capacity.