wrong pitch in simulation (despite correct design)

[heilubke]

Dear PVsyst team,

I am facing a problem since i updated to 7.2.2 (even though the problems of 7.2.1 were mostly solved).

The parametrization for backtracking simulation is not using the settings as provided in the PV field design (7.0m) but another value (6.6m). There is no indication where this value might come from.

Please see screenshots:

 

• Screen1: Object editing dialogue cites pitch = 7.00 m.

• Screen2: The “Backtracking Management” dialogue cites pitch = 6.60 m and does not appl the actual module size for “Collector width”.
  
  (however it lists the correct min. pitch value of 7.00 m in the fields table).

• Screen3: This results in the Orientation Parameters dialog also citing the wrong pitch = 6.60 m not considering correctly the PV module size.

 

The resulting problem is quite embaracing: I am simulating the as-built design for two similar projects in different sites. The equipment is the same, technical design is similar. After simulating the results with v.7.2.1 the client called ou attention to the errors in that version (diffuse not considered) and asked for correction (turning red already from embarrassment). Then we simulated both systems with v.7.2.2 and one system receives a ~5% increase of incident irradiance gain from trackers while the other doesn't (turned bright red).

Now, adjusting the pitch in the backtracking to the actual pitch the second system results with an additional gain of 3.2% from tracking (versus v.7.2.1 sim.). Possibly, the difference from ~5% to 3.2% results from higher diffuse share. But it all seems doubtful now.

I'd really appreciate if you could provide a feedback regarding these problematic results from wrong backtracking parameters.

Object editing dialogue: pitch=7.00m

Backtracking Management dialogue: pitch = 6.60 m

Orientation Parameters dialogue pitch = 6.60 m

[HLubke]

problem solved in latest updates...