SAT at different azimuth near shading loss

[Vladislav Iliev]

Hello. 

I have the following staging: same site and two single axis tracker (N-S) variants:

- idenatical parameters expet the azimuth.One is 0 degree , one is -47degree.

- Backtracking is ON, Latitude  44° 49' 0" N, flat/No terrain

Results of simulation indicate better overall performance of the 47degree. Whitch contradicts with articles about performace of deviations from the 0 azimuth.

Main difference comes from near shadings.

Can someone explain those results? Comparison attached.

 

Sincerely, 

Vladislav

 

[Vladislav Iliev]

Anyone?

[Michele Oliosi]

This indeed is inconsistent. We have observed recently that for trackers that do not have azimuth zero, there is a bug for a certain diffuse shadings calculation mode. I suspect this is what is happening here.

In the 3D scene, if you go to Tools > Tracker diffuse shadings definition, you can switch between the modes:

• automatic (=central tracker above a threshold* number of trackers / = all trackers below that threshold*)
• central tracker (fast)
• custom tracker (fast)
• all trackers (most accurate, slower)

The "Central tracker" and "Custom tracker" modes do not work well with azimuths away from zero because the neighbor identification fails. I would suggest to use the mode "all trackers".

* The threshold can be modified in the advanced parameters:

Read https://www.pvsyst.com/help/tracking_diffuse.htm for more details.