Solar controllers or charge controllers are essential components in off-grid solar systems.
The controller regulates the charging of batteries, which makes it possible for batteries to last long and not be overcharged or over-discharged.
PWM and MPPT solar controllers are the two main types of solar controllers available in the market today.
In this comparison guide, we shall look at the differences between PWM and MPPT solar controllers.
PWM Solar Controllers PWM (Pulse Width Modulation) solar controllers are older technologies compared to MPPT solar controllers.
PWM controllers are suitable for small solar systems, as they have limited capacity.
PWM solar controllers work by connecting the solar panel to the battery in such a way that the battery charges slowly when it is near full capacity and quickly when it is empty.
PWM solar controllers also have a voltage regulator that prevents overcharging of batteries when the solar panel generates excess voltage.
MPPT Solar Controllers MPPT (Maximum Power Point Tracking) solar controllers are newer technologies compared to PWM controllers.
MPPT controllers are suitable for large off-grid solar systems and grid-tie solar systems.
MPPT solar controllers work by tracking the optimal voltage and current production point of the solar panel.
This technology enables MPPT controllers to convert the excess voltage and current to usable power, boosting the charging efficiency of the battery and maximising the output of the panels.
Differences between PWM and MPPT Solar Controllers
1. Efficiency: MPPT solar controllers are more efficient than PWM controllers. MPPT can convert excess voltage from the solar panels into usable power, while PWM cannot.
2. Capacity: MPPT solar controllers are ideal for large solar systems, while PWM controllers are only suitable for smaller systems.
3. Cost: MPPT solar controllers are more expensive than PWM solar controllers.
4. Flexibility: MPPT solar controllers are more flexible since they can handle a wide range of voltages. PWM controllers have size limits on the panels they can handle.
5. Battery Life: MPPT solar controllers can extend battery life as they can prevent overcharging, while PWM controllers risk overcharging when batteries are fully charged.
Conclusion Both PWM and MPPT solar controllers are tailored to different types of solar systems.
PWM controllers are great for small solar systems, while MPPT controllers are ideal for larger solar systems.
Although MPPT controllers are more expensive than PWM controllers, they have greater efficiency and flexibility, and they can extend battery life.
Therefore, it is wise to choose the type of solar controller that is most efficient and suitable for your solar system needs.

Comparison of MPPT Solar controller and PWM solar controller