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

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

   The smalloff-grid system under 2kW is mainly used in poor and non-electric areas, suchas remote mountainous areas and some poor countries in Africa. It mainly solvesthe lighting demand. The users are very sensitive to the price. Therefore, itis suggested to use PWM charge controller, modify the wave inverters, and integratethe controller, inverters and batteries. This method has the advantages ofsimple structure, high efficiency, convenient connection for users and lowprice. It can also drive light bulbs, small televisions and small fans.

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