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Hello PVsyst! I have a vertical bifacial East-West system, and I want to make sure that the irradiance received from the East-side should be the same whether I use east-front facing or west-front facing config. Same for West-side. Therefore, I made 2 simulations with the above 2 config, then compare just the Ressource losses (top part of the Loss Diagram). The results are attached as images. I don't think the horizon loss and soiling loss is integrated in the backside losses, hence I excluded these 2 losses from the front-side. The structure shading loss BackShd is also excluded for the back-side, in hope of a fair comparison. For the result, I expect the "Global Irradiance on front side (no soiling, no horizon shading)" of one configuration (East/West) to be more or less similar with the "Global Irradiance on rear side (no soiling, no structure shading)" of the other config (West/East). I highlight the 2 couples values in green and orange. West front-facing result: East front-facing result: Only the green pair seems to be similar (1.1% difference), the orange pair is 4.5% difference. This is already much better than some previous version of PVsyst, but I still want to know if my expectation is logical and if yes, what are the reason for this difference (the orange pair). Thank you!