3D scene physical layout

Imported .PVC file and terrain data misalignment

When importing both the 3D shading scene and the terrain data, these 2 files can become misaligned due to the PVsyst origin auto selection, and the result can look like below:

To correct this, when prompted with the Import result window, the user must uncheck the automatic translation and change it to x=0, y=0, and z=0.

The reason is that when importing the terrain data, PVsyst automatically sets the terrain object at the origin of PVsyst. However, when importing the 3D shading scene, PVsyst detects and sets the origin according to the AutoCAD design. This action will correct the misalignment by setting the 3D shading scene file (.PVC) origin to the same origin as your terrain file (.csv).

Rotate the whole scene

PVsyst defines its coordinate system as follows:

This issue occurs when the project location in PVsyst is set in the Southern Hemisphere. There are two ways to correct the orientation of the imported design depending on the PVsyst version that is available or the user.

PVsyst 7.3 or newer

PVsyst will automatically detect and suggest rotating the import result orientation:

PVsyst 7.2 or older:

PVsyst did not support project location detection in 3D scenes, therefore the rotation suggestion is not available. Users can adjust the orientation of the project manually by selecting Edit, rotating the whole scene, and inputting the desirable azimuth.

The number of modules and orientation changed

It is important for PVsyst and any yield calculation software to get the collective plane area. When there is no user input for the module type in the system setting that the simulation can use, PVsyst collects this data by assuming the sensitive area from the 3D model. That results in the module orientation discrepancy between the 3D model and the AutoCAD layout.

Occasionally, frames with multiple joint gaps or motor gaps also have an incorrect number of modules in length compared to the frame setting defined in PVcase

The user should ensure that the PV module is selected for the system. At this point, PVsyst will automatically calculate the sensitive area by the reference PV module, and modify the module orientation within the 3D scene to the correct orientation.

The user can modify both the number of modules and the module orientation manually by selecting the frames and using the Modify selected objects under the Edit tab.

The user should be able to modify the sizes detected by the module, the module orientation to be in portrait, and the number of modules in the X direction

Advanced parameters settings

*User discretion advised: The user should consider using their best effort to correct the model using other methods unless it is an utmost necessity to use the described methods below. Modifying the advanced parameters should only be done by expert users. The default values are set to ensure the accuracy of the simulation. Modifying these values might result in some inaccuracies, due to working with an idealized model* 

Bifacial 2D model error

After seemingly a smooth export, users might want to simulate a fixed tilt design on a complex terrain with a bifacial module to capture the additional production. However, after selecting the bifacial system in the PVsyst system, users get an error warning as the simulation cannot be executed.

The PVsyst internal algorithm checks to ensure the 3D model accuracy for most projects. However, on more complex terrain, these limitations can prevent users from performing the simulation. In order to correct this error, the user must update the advanced parameters to increase the tolerance check these parameters using the steps below:

  • Save and exit the current project
  • On the main page, select Setting > Edit advanced parameters
  • Search for “Pitch RMS limit for bifacial 2D models” and increase this tolerance. By default, this value is 0.1m, and the threshold is four times this value at 0.4 for the calculation. By increasing the value of this parameter, the user allows PVsyst to simulate the module with a threshold of four times the value of the advanced parameter
  • For N-S horizontal axis trackers designs, PVsyst also checks for the homogeneity of the axis tilt. The threshold for this value is 2 degrees and it can be modified by editing the “Max tilt axis for the bifacial 2D model”

As PVsyst suggested, these parameters should only be modified by advanced users. To learn more about the impact of these modifications, users can consult the PVsyst help article here

However, it is important to be able to capture bifacial yield on complex terrain without risking the accuracy of the production model. Users can request a trial to PVcase Yield, which can simulate the site’s performance without layout geometry limitations.

Learn more about PVcase Yield

Area of 3D fields error

After importing and/or manually modifying the imported near-shading scene (.PVC file), the user may receive an error message that the PV area in the 3D field is higher/lower than the area defines in the system

When encountering this error message, it is recommended that the user follows the steps in this help article to conduct the initial check between PVcase design and PVsyst “System”. 

If this error is consistent even after the initial check, the user can consider a more aggressive approach in the advanced parameters setting by following the steps below:

  • Save and exit the current project
  • On the main page, select Setting > Edit advanced parameters
  • Search for “Shading: absolute min shading/field area ratio”  and decrease this tolerance. By default, this value is 0.92 (7% difference). By decreasing this value, the user increases the percentage difference in the active area between the 3D scene and the “System” thus allowing the user to continue the simulation