Smart Module and Smart Retrofit technology corrects for mismatch which results from uneven strings in parallel. It enables a variance in string length of up to 25%.
Requires single or dual add-on optimizers, 1st gen smart modules, or TS4-O/TS4-L.
Here are some important guidelines to follow when designing strings of different lengths:
- Strictly follow the inverter minimum and maximum MPP voltage windows.
- Design the strings to be as long as possible within the voltage window to reduce homerun losses and improve efficiency.
- Design shade on the longer strings or evenly across strings as much as possible.
- Have the number of longer strings as low as possible (i.e. prefer 2 shorter strings and 1 long than only 1 shorter string and 2 long strings).
How to Calculate Maximum String Mismatch
To calculate maximum amount of string-to-string mismatch use the following equation:
1-(short string/long string)= % mismatch; must be less than or equal to 25%
Short string voltage must be above the inverter MPP minimum and the longest string must be below the inverter MPP maximum voltage. Remember to adjust the voltage of the shorter string for the historical high temp for your area.