Axis Azimuth with SAT in v6.47

[Kyle Kattke]

I have a Single Axis Tracker array with backtracking activated. I set the azimuth to 19 degrees within the "Object Positioning" settings.

When I simulate with PVsyst v6.44, the report states under "Simulation Parameters" an "Axis Azimuth" = 19 degrees

Production = 3802 MWhr/yr

I don't make any modifications to the project, and I open it with v6.47. When I simulate, the report states under "Simulation Parameters" an "Axis Azimuth" = 0 degrees

Production = 3823 MWhr/yr

In v6.47, I have found that I can get the report to state 19 degrees azimuth and 3802 MWhr/yr production with the following sequence of steps:

- turn off backtracking

- calculate shading table

- turn on backtracking

- calculate shading table

- perform simulation

But, when I re-open v6.47 and re-simulate, it reverts back to reporting 0 degrees azimuth and 3823 MWhr/yr production.

Regards,

Kyle

[Kyle Kattke]

I found this same problem occurs with v6.49.

Regards,

Kyle

[johank]

I'm having the same issue in v6.52.

I'm simulating SAT with backtracking and ran a few comparisons, attached. Setting azimuth in the 3D Shading Scene alone appears to only affect IAM loss, leading to a small reduction in GlobEff. It does not appear to affect incident (POA) irradiance, GlobInc. This was unexpected.

Changing GlobInc required this:

- define 3d scene, use "position in scene" (ctrl+b) to set azimuth

- compute shading factors table

- set azimuth under "Orientation" (it says it's w.r.t. to 3d shadings but I suspect that's not the case)

This prints the correct azimuth angle in the report. However, the value under "Orientation" resets to 0 after the simulation.

The change in GlobInc starts to be fairly significant for larger azimuths. Please advise.

The forum does not allow adding xlsx, happy to send via email if it would be helpful.

Thank you!

[André Mermoud]

There is indeed an error in versions 4.46 to 6.52: when defining a not-south azimuth for the Single axis tracking object in the 3D scene, this is not taken into account in the simulation.

This was corrected in the V 6.53.