bapossatto

Considering: Is any calculation of energy losses due to stow made in PVsyst? If so, is the wind direction taken into account to position the tracker at + or - 60º for example?

Assuming initially that in the "Energy management" area you have set "Inverter temperature for PNom evaluation" to "External ambient temperature (outdoor installation)" in the same way for both inverters, perhaps it is valid to analyze the "Grid power limitation" field, also in the "Energy management" area; if the limitation occurs at the inverter level and considering that the installed power of the systems is different, there will probably be a difference there. Anyway, I believe that PVSyst has a great difficulty, which is the modeling considering the temporal and spatial variability of irradiance in a large-scale power plant. See the article below: https://www.sciencedirect.com/science/article/abs/pii/S0038092X19304530 You will see that a central inverter will suffer less clipping by overradiance events, but despite this, the consideration of hourly data generates modeling errors that can be significant.

Dear Mr. Mermoud, Considering the "diffuse shadows" losses, should I consider this fact in a PR test for example? Because when taking into account the value of GlobInc for the determination of the reference PR, it would be ignoring the losses due to diffuse shadows that the pyranometer will measure during its operation. In this sense, I understand that it would be correct to use the value "GPOA = GlobInc - Near Shadings: irradiance loss + Ground reflection on front side" as a reference for calculating the PR. Thanks, Benhur Possatto

Hello No, it doesn't take the rear side irradiance into accounu, until know the biracial performance ratio is calculated as the mono-facial. "PR for bifacial systems The definition of the performance ratio should be something like a standard, defined by an official instance, and accepted by everybody. Now I have not yet seen any reference which would define a performance ratio for bi-facial systems. Therefore PVsyst cannot propose any specific value in the present time. The value provided presently with the PVsyst results uses the definition of the Monofacial systems, so that the bi-facial gain comes as an increase of this ratio. NB: The main objective of the PR is to find an indicator for comparing real and simulated data, therefore which may easily be evaluated using simple (and "primary") measured data. However neither the rear side irradiance, nor the part of the bifacial gain is available in usual measurements." Source: https://forum.pvsyst.com/viewtopic.php?t=31 Best Regards, Nedal Nassar And what about now... IEC 61724-1:2021 is available!