Electrical loss according to string - Tracking systems

[gpuy]

I would like to know if there is a reason for not obtaining "electrical loss acc. to string" when using a Horizontal Tracking System and simulating as "According to Module Strings",  regardless of the "fraction for electrical effect".

With fixed structures, there is "electrical loss acc. to string" when simulating as "According to Module Strings", since shadows generate mismatch of electrical response of the modules in series and strings in parallel.

I was expecting the same for Horizontal Tracking Systems (despite backtracking) since once there are shadows ("near shadings: irradiance loss" is not 0), the mismatch of electrical response of the modules would cause a loss.

[Michele Oliosi]

The "Near shadings: irradiance loss" also includes diffuse shadings. In PVsyst we consider that these do not produce any electrical mismatch. It seems that your backtracking is working well, since the electrical losses according to strings are 0%.

[gpuy]

2 hours ago, Michele Oliosi said:

The "Near shadings: irradiance loss" also includes diffuse shadings. In PVsyst we consider that these do not produce any electrical mismatch. It seems that your backtracking is working well, since the electrical losses according to strings are 0%.

Thank you for your answer Michele.

I´ve checked the ShdBLss (Loss on the beam component), ShdDLss (Loss on the diffuse component), and ShdALss (Loss on the albedo component). They represent the next porcentage of the total shading loss:

• ShdBLss: 20%
• ShdDLss: 38%
• ShdALss: 42%

Since ShdBLss > 0, is it still normal to have electrical losses according to strings of 0%?

[Michele Oliosi]

Hmm indeed that doesn't seem normal. I'd try to try and recompute the shading factor tables, if you are using the tables.
If that still doesn't change the results, I would suggest sending us your project (exported via the main window > File > Export project). We'll be then able to review if any parameter is causing that or if there is a bug to be corrected.

[gpuy]

On 11/28/2022 at 9:58 AM, Michele Oliosi said:

Hmm indeed that doesn't seem normal. I'd try to try and recompute the shading factor tables, if you are using the tables.
If that still doesn't change the results, I would suggest sending us your project (exported via the main window > File > Export project). We'll be then able to review if any parameter is causing that or if there is a bug to be corrected.

Thank you for your support, Michele.

Since recomputing the shading factor tables didn´t change anything, I´would like to send you the project. Shall I do that via email?

[Michele Oliosi]

Yes ! You can send at support@pvsyst.com

 

[MNWild]

Following

 

[Elivelton Freitas]

how was this case resolved?

[Michele Oliosi]

In the end, the results were consistent with the backtracking (on flat ground, therefore ShdElec = 0). So no issue after all.
Did anyone experience the same issue ? Or were you following by interest ?