I am running simulations in SAM and PVSyst with the aim of comparing the two software's yield results for a vertical E/W-oriented (east-facing) bifacial PV system in the Netherlands. The results I'm obtaining diverge substantially and exhibit a peculiar pattern. When modelling a conventional N/S-oriented (south-facing) system with moderate tilt (around 30 degrees), the results are in close agreement. However, when considering E/W-oriented systems, the results start significantly diverging, especially for high tilt angles (maximum deviation of around 70% is reached at 90 degrees).
Since I am interested in using SAM for modelling vertical E/W systems for actual projects, I am concerned about these observed discrepancies. That been said, I'm seeking guidance from SAM experts or people who have experimented with similar systems in SAM or PVSyst. Any insights regarding the source of the discrepancies or how to resolve them would be appreciated. Also, I would be grateful if someone could point me to actual reference use cases of vertical bifacial PV simulations in SAM.
Thank you in advance.
