what's in a off grid solar power system ?

The solar power generation system consists of a solar  panel , solar controller , solar inverter , solar battery 

The functions of each part are as follows:

1) Solar panels: solar panels are not only the core part of the solar power generation system, but also the most valuable part of the solar power generation system. Its function is to convert the radiant energy of the sun into electricity, or send it to the battery for storage, or drive the load to work. The quality and cost of solar panels will directly determine the quality and cost of the whole system.

2) Solar controller: the function of solar energy controller is to control the working state of the whole system, and to protect the battery from overcharge and overdischarge. Where the temperature difference is large, the qualified controller should also have the function of temperature compensation. Other additional functions such as light control switch and time control switch should be the functions that the controller should have.

3) Storage battery: generally lead-acid battery, Gel battery,  or lithium battery can also be used in small systems. Because the input energy of the solar photovoltaic system is extremely unstable, it is generally necessary to configure the battery system to work. Its function is to store the electricity generated by solar panels when there is light and release it when needed.

4) Solar  Inverter: in many occasions, it is necessary to provide AC power supply of 220VAC and 110VAC. Because the direct output of solar energy is generally 12VDC, 24VDC, 48VDC. In order to provide electricity to the electrical appliances of 220VAC, it is necessary to convert the DC power generated by the solar power generation system into AC power, so it is necessary to use DC-AC inverter.