Maximum Power Point Tracking (MPPT)
Achieving Reliable Solar Performance for Critical Applications
A well-designed solar lighting product uses an Energy Management System (EMS) that ensures the energy collected from the product's panel gets safely stored in the battery and efficiently delivered to the light's LEDs.
The solar energy available to the panel varies based on where a product is installed, the time of year and daily weather conditions. Similarly, a battery's charge capacity varies with extreme heat and extreme cold. A good EMS system will include a charge controller that ensures the battery stays topped-up under these varying conditions. It will also protect the battery from damage due to overcharging and overheating. Different types of EMS charge controllers can help you get more value out of your system under varying installation conditions.
Pulse Width Modifier (PWM) controllers: This common controller technology is used satisfactorily in many consumer applications. A PWM controller monitors the battery's state-of-charge and lowers the charging current as the battery gets close to maximum capacity. This is a simple solution to help ensure that the battery isn't damaged from over-charging.
Maximum Power Point Tracking (MPPT) controllers: Often a more expensive feature, controllers with MPPT are ideal for challenging solar locations (for example: locations with long winters or frequent cloudy conditions). MPPT controllers allow you to have a high voltage panel paired with a lower voltage battery. This means your panel can collect the maximum amount of available solar energy during the ideal charging hours. The MPPT controller receives the higher voltage and converts it to a lower one that the battery can tolerate without damage.
MPPT is an excellent feature for industrial applications like safe-navigation aids which are typically installed in remote locations and where a light's failure could have critical consequences.