jbennett

Similar problem for me. I am trying to model carport canopies with bifacial modules. 3 degree tilt. Some projects have only one azimuth, others have multiple azimuths. However, none of these arrays would fit the description of a "shed" in PVsyst. And defining them in the 3D scene doesn't seem to make a difference--PVsyst says the systems are not suited for the model computation. Can anyone confirm that modeling bifacial systems, can ONLY happen with sheds? And if yes, any appropriate work-arounds to get by this limitation (e.g. split each array into two subarrays of two sheds each, and make the pitch very large between them? Thanks, John

Very good. Thanks again for the help, SolarGuru!

@solarguru Ok, got it. Did not realize that the 3D scene didn't take the module diode information from the .PAN file into account when modeling between portrait and landscape orientation. That is very useful information. Last question from me here. For "unlimited sheds" orientation, when in horizontal, should the "cell size" (transverse) also be doubled from the default, to account for two cells stacked in the cell group? I.e. in portrait, cell size (transverse) is 15.6 cm, and in landscape it would be 31.2 cm? Thanks a million here. :D

@solarguru Thanks for the quick response! Does this mean that the unlimited sheds orientation cannot account for bypass diode behavior at the sub-module level? Which is to say, when the bottom row of cells is completely shaded, it assumes all diodes open, regardless of module orientation or the number of strings on an MPPT? Thanks again, John

Dr Mermoud, I am modeling sites using SolarEdge inverters with ballasted roof mounts with landscape module orientation. Tilt is 10 degrees and pitch is 1.37 m. Each row is only one module in height. How to best model the row shade for such a system, if we assume no near shadings besides inter-row shade? I have read the "help" article titled "Solar Edge Architecture" and your FAQ post "How to evaluate the effect of by-pass diodes in shaded arrays." However, it is not clear to me if the unlimited sheds orientation accounts for the effects of the bypass diodes when modules with optimizers are in landscape orientation. Or can this only be modeled via "detailed electrical calculation according to module layout"? Many thanks, John

Dr. Mermoud, Have there been any updates to PVsyst's capabilities with regard to retro-transposition of POA irradiance to GHI for single-axis trackers? If yes, can you provide instruction on how the tracker type should be indicated when using the DEMO files you referenced previously? Many thanks, John

Dr. Mermoud, Can you clarify how the "unlimited horizontal tracking" orientation differs from past tracking orientations, and how to best put it to use? I made an experimental project with a basic tracker layout (with backtracking) to compare the production of a system with "unlimited horizontal tracking" to one with "horizontal or tilted N-S axis." For the latter of the two, I am keeping axis tilt at 0 degrees, but have to construct a tracker in the 3D scene. All other variables are the same. However, the "horizontal or tilted N-S axis" orientation model producing slightly more than "unlimited horizontal tracking." Any ideas why there is a difference? Can you provide general guidance on when each of these orientations is best utilized? Many thanks, John

Good to know. Thank you for the confirmation!

Thanks for the response. Follow up question: if we had a dedicated global horizontal irradiance sensor, would that enable PVsyst to compare the measured production against the simulated production for a single-axis tracker? If so, I may be able to convince my superiors to include a horizontal irradiance sensor in future projects. Thanks again!

Hi Andre, In a response to a 2013 question from another user, you that said PVsyst was unable to transpose global POA irradiance to global horizontal irradiance for tracking systems. Has any progress been made since that time? I am working on several single-axis tracking systems that have POA irradiance sensors and sensors for wind speed, ambient temperature and array temperature. There are no global horizontal irradiance sensors. I would like to analyze the measured production against the simulated production, adjusted for weather conditions. However, when I try to format the protocol file and indicate the presence of POA irradiance data, I am not allowed to indicate that the system is a N-S single-axis tracking system with backtracking. There is only a space to indicate the tilt and azimuth of the plane orientation, which would only be relevant for a fixed-tilt system. Am I missing something, or is this transposition still not possible? Many thanks! John

Hello! I'm working on several projects with a N-S single-axis tracker employing a backtracking strategy, and am setting up the layouts in the 3D scene. Wanted to ask if anyone can confirm that for layout parameters, "Pitch E-W" refers to center-on-center post spacing, as opposed to the narrower inter-row spacing. I have not been able to find a clear answer regarding which of these two values PVsyst uses. This will have major implications for our proposed layouts and production estimates, so any advice will be most appreciated! Thanks, John