Batch simulation yields different results compared to individual simulation

[Aquin]

Hello,

I am currently doing simulations on a single axis-tracker set-up, on a horizontal N-S axis. The modules are considered bifacial. I defined the shading scenario with the 2D model, and use the unlimited trackers 2D model in the Bifacial system definition

I want to compare the annual yield in 30 different locations. For this I use batch simulation, with changing meteo data files.

This works well, but the results I get from the batch simulation is different than when I do the exact same set-up, without even changing project for a single simulation.

Why is there a difference, I would assume to get the same results in individual simulations as in batch.

[Michele Oliosi]

Hi Aquin,

Thanks for the feedback ! Could you tell us a bit more on the differences you observe (magnitude, some examples,...) ?
Is that systematic for all locations?

[Aquin]

Hello,

I finally understood where the difference is coming from: When selecting the module, I want to change the bifaciality factor.  In "sizes and technology" it is possible to modify this manually. The individual simulation will consider this new manually entered value correctly. As soon as I do a batch simulation however, it seems like the simulations are done with the default value. 

Alternatively, I understand I should save the module with my own values as a new PV module in a PAN file. But then I don't know how to import it. I can only select a module from the list of modules included with PVSyst.

FYI I am using version 6.88

[Aquin]

Hello again,

I have found the issue, I should indeed use my own PAN file, which ultimately just shows in the list of panels, but with the same name as the standard modules. The only way of understanding which module you chose, is by looking at the file name in "basic data".

It is now resolved.

KR

Aquin

[dtarin]

What I have found helpful for custom PAN files is to rename the manufacturer to something else in the PAN file, such as my company name or custom or "[manufacturer] custom", so they don't show up mixed with the regular 3rd party or manufacturer PAN files.