PWM and MPPT controllers have their own unique advantages and disadvantages. The choice of the scheme depends on the design characteristics, cost and external environment of solar photovoltaic arrays. When choosing, we should consider the following factors:

        PWM technology is mature, the circuit is simple and reliable, and the price is cheap, but the utilization rate of components is low. MPPT solar controller refers to the solar controller with maximum power point tracking function. There is a BUCK voltage-reducing circuit between the module and the battery, and the utilization ratio of the module is about 90%.

        The small off-grid system under 2kW is mainly used in poor and non-electric areas, such as remote mountainous areas and some poor countries in Africa. It mainly solves the lighting demand. The users are very sensitive to the price. Therefore, it is suggested to use PWM controller, modify the wave inverters, and integrate the controller, inverters and batteries. This method has the advantages of simple structure, high efficiency, convenient connection for users and low price. It can also drive light bulbs, small televisions and small fans.

        MPPT controller is recommended for off-line system with 2 KW or more. It has high utilization ratio of components, high efficiency of whole machine and flexible configuration of components. Generally speaking, no technology is the best, so for users, they should listen to experts'opinions and ensure that they choose the right controller to meet their needs.