The solar power generation system is composed of solar cells, solar controllers and batteries (groups). If the output power supply is AC 220V or 110V, an inverter is also required. The functions of each part are:
（1） Solar panel: solar panel is the core part of the solar power generation system and the most valuable part of the solar power generation system. Its function is to convert the radiation capacity of the sun into electric energy, or send it to the storage battery for storage, or promote the load to work.
（2） Solar controller: the function of the solar controller is to control the working state of the whole system and protect the battery from overcharge and over discharge. In places with large temperature difference, the qualified controller shall also have the function of temperature compensation. Other additional functions such as optical control switch and internal time control switch shall be optional to the controller;
（3） Battery: generally lead-acid battery. In small and micro systems, nickel hydrogen battery, nickel cadmium battery or lithium battery can also be used. Its function is to store the electric energy generated by the solar cell panel when there is light, and release it when necessary.
（4） Inverter: the direct output of solar energy is generally 12VDC, 24VDC and 48VDC. In order to provide power to 220VAC electrical appliances, it is necessary to convert the DC power generated by the solar power generation system into AC power, so DC-AC inverter is required.