Near Shadings Simulation

[Tim K]

Hi,

I am attempting to model a modified single axis tracker in PVsyst by constructing a shading scene in "Near Shadings".

I was hoping to simulate a whole (1) MWAC inverter block worth of trackers, but after building the scene and trying to run the simulation

PVsyst runs very slowly and eventually ends the program.

Therefore, I decided to scale up by tracker rows and E-W center to center row spacing by a factor of 10 in order to run the simulation. That way,

the area of shading will be very close to the area of the system and I can produce a shading table. So for instance, if a "real-life" typical row is 2m

in width and c-c row spacing is 6.1 m, I scaled them up by a factor of (10) to 20m and 61m respectively in order to successfully run the simulation. Is

this the correct approach for using "Near Shadings"?

Also, if I am implementing a N-S tilt in my simulation, what does PVsyst assume for shading on the modules in the N-S direction? If the spacing (pitch)

is not great enough and there is shading on the modules, how does this affect each individual module's production?

Thank you for your help.

Tim

[André Mermoud]

Scaling the tracking rows (by a same factor for the tracker's width and pitch) is indeed a very good idea, that I adviced for sheds since a long time.

However:

- there may be errors due to edge effects at the extremities: if you also scale the tracker lenghth (i.e. diminish the number of trackers) I think the simulation should be quite representative.

- if you use shadings "according to strings", you should also scale the string's sizes (i.e. a string rectangle will represent several strings).

- this is not correct for the electrical losses calculated with the "module layout", which are based on the module's sizes.