What is difference between MPPT and PWM?

1) MPPT controllers are more expensive than PWM controllers, however MPPT controllers have higher charging efficiency, especially in cold climates. The MPPT controller also supports wired series connection of more photovoltaic (PV) panels (high voltage drop), 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) Compared with the MPPT controller, the biggest disadvantage of the PWM controller is the efficiency. The PWM charge controller cannot charge the maximum power generated by the photovoltaic (PV) array, and its overall efficiency is usually between 65-85%. , on the other hand the MPPT controller will ensure that the solar array 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) 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, and the temperature range of the solar charging unit is 45-75 °C. MPPT controllers are a better choice for larger systems, and their higher efficiency means good economics. In addition, the MPPT controller allows users to obtain the maximum power from the photovoltaic (PV) array, which has obvious advantages when there is additional power demand and the limited space cannot expand the size of the PV array.