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Different Orientations

Optimization enables modules to be placed in the same string on different orientations or pitches.

On strings with split orientations (e.g. East-West), each major orientation should meet the minimum inverter voltage.

While not in the sun, modules should not be considered to be contributing to the string voltage for inverter operation.

Generally, for any condition, ensure panels in major orientations can generate enough voltage on the same string to start up the inverter, and maintain string voltage within the inverter's operating voltage range. The higher the string voltage (within range) the better.

When using TS4 with Predictive IV (-O or -L covers) to design different orientations, selective deployment is possible in a few cases listed below. When using gen. 1 Smart Modules (non-TS4) or 2ES add-on optimizers; always deploy on 100% of an MPPT to enable the different combinations. Assume the residential systems described below are built with 240V SMA Sunny Boy 3800TL-US inverters (datasheet available here) and Trinasmart 270W modules (datasheet available here)

  • Cases with most panels facing the same direction, and a small portion, which can’t generate high enough voltage to start up the inverter, facing a different direction. For example, with 9 panels on a string; 6 of them facing south and the remaining 3 panels facing west:
    • The SMA inverter's startup voltage = 150V, and the Trinasmart modules in direct sunlight contribute 30.9V each (assume 30V for the sake of simple calculations)
    • The 6 south-facing modules alone will start up the inverter, (6 modules * 30V = 180V > 150V) and the 3 west-facing modules will not (3 modules * 30V = 90V < 150V)
    • Conclusion: Deploy TS4-O only on the 3 panels that are facing west
 
TS4-O or TS4-L: Selective deployment   Non-TS4: 100% deployment
  • Cases where each orientation is able to produce enough voltage on a single string for the inverter to start up. For example; a string of 12 panels with 6 panels facing south, 6 panels facing west.
    • Assume the inverter's startup voltage = 150V, and that modules in direct sunlight contribute 30V each
    • Each orientation will have enough voltage to keep the inverter on (6 modules * 30V = 180V > 150V) 
    • Conclusion: Deploy 100% optimization to ensure that the array voltage is high enough keep the inverter on throughout the day. This is especially important for systems with half an array facing east, and half an array facing west.
 
In this single string example, each orientation is able to produce enough voltage for the inverter to start and stay ON. Deploy 100% optimization 
  • Note that there's no limit on how different the azimuths are, as long as voltages of the inverters are met.
  • On multiple parallel strings, follow the same voltage guidelines, and deploy 100% optimization (TS4-O, TS4-L, gen.1 Smart Modules and/or 2ES).
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