why choose MPPT for solar power system

The solar controller is used in the solar off-grid solar power generation system, which can automatically control the solar panel to charge the battery.

Coordinate the work of solar panels, batteries and DC loads, monitor the Battery charging and display the current、 voltage and  solar panels charging to the batteries conditions ,can effectively prevent battery overcharging, with reverse and short circuit functions.

The solar controller needs to coordinate the work of solar panels、 batteries、 and DC loads, to ensure the stable operation of solar off-grid power generation system。

At present, there are mainly two kinds of solar controllers on the market, MPPT solar controller and PWM solar controller. on the market.

Today let's discuss the difference between MPPT solar controller and PWM controller

PWM is pulse width modulation, which refers to the use of the digital output of the microprocessor to control the analog circuit. It is a method of digitally encoding the level of the analog signal.Controlling analog circuits digitally can significantly reduce system cost and power consumption， PWM  compared with the MPPT controller, the biggest disadvantage of the PWM controller is its low efficiency. The PWM charge controller cannot charge the maximum power generated by the solar panel.Its overall efficiency is usually between 65-85%. The PWM mode technology is mature, the circuit is simple and reliable, and the price is cheap, but the utilization rate of components is low, which is suitable for small systems

The temperature range of the solar charging unit is 45-75°C. In addition, the PWM solar controller can only be matched with the relevant voltage. For example, the 12V (17V) system panel can only be matched with the 12V controller and the battery. It is suitable for some small off-grid systems below 2kw. The structure is simple, the user wiring is convenient, and the price is also relatively Cheap.

The MPPT solar controller is more complicated, and the cost is also higher. The price is usually several times - ten times that of the PWM solar controller.The MPPT controller can detect the power generation voltage of the solar panel in real time, and track the highest voltage and current value (VI), so that the system can charge the battery with the maximum power output.

Compared with the PWM solar controller, the MPPT solar controller has a maximum power tracking function, which can ensure that the solar panel always outputs the maximum power during charging, and will not be affected by temperature. In terms of charging efficiency, it is naturally better than PWM. Higher.The MPPT solar controller has a larger space for use. In general, the voltage of the solar panel can be used between 12V-160V, and the battery voltage of 12V, 24V, 48V or 48/96V can be automatically recognized, and the applicability is stronger, suitable for more than 2kw. The large-scale off-grid power generation system has high efficiency and flexible component configuration.

1) MPPT controllers are a bit more expensive than PWM controllers, however MPPT controllers have higher charging efficiency, especially in cold climates.The MPPT controller also supports connecting more solar panels in series (high dropout), which is also a big advantage.In this case, the cross-sectional area of the connecting cable can be greatly reduced, resulting in a corresponding reduction in the overall cost of the system.

2) The MPPT controller will ensure that the solar panel is always in the best operating condition. In some cases, such as when the weather is cold, the charging efficiency provided by the MPPT method is 30% higher than that of the PWM method (high charging efficiency).

3) MPPT controller is a better choice for large systems, its higher efficiency means good economic benefits. In addition, the MPPT controller allows users to obtain maximum power from the solar panel system, which is a clear advantage in situations where there is additional power demand and limited space prevents the expansion of the solar panel system.

https://swnpower.com/products/49/100a-120a-150a-mppt-solar-charger-controller