PV loss due to irradiance level changes when changing the module degradation loss

[gpuy]

With certain modules, the PV loss due to irradiance level changes when changing the module degradation loss. This only happens when the module degradation loss is changed from 0% to 0.4% but it doesn´t happen for changes from 0.4% to bigger values. But since the PV loss due to irradiance level stands for the low module efficiency with low irradiances... shouldn´t it remain constant?

[dtarin]

The collector area is not the same in both simulations. Can you retest with identical systems?

[Michele Oliosi]

Another point that may be at play: the module parameters have to be recomputed to be able to apply the degradation. If you are using a module that doesn't have standard one-diode parameters to begin with, once the aging is applied, they may change due to the recomputation of these parameters.

[gpuy]

On 11/3/2022 at 1:10 AM, dtarin said:

The collector area is not the same in both simulations. Can you retest with identical systems?

Sorry, I attached screenshots from 2 different projects. But I assure you that´s not the problem as you will see:

[gpuy]

On 11/3/2022 at 1:29 PM, Michele Oliosi said:

Another point that may be at play: the module parameters have to be recomputed to be able to apply the degradation. If you are using a module that doesn't have standard one-diode parameters to begin with, once the aging is applied, they may change due to the recomputation of these parameters.

Thanks for your answer.

How could I check if the module I´m using has standard one-diode parameters?

[Michele Oliosi]

Is it a PAN file provided by a manufacturer or a module from the database ?

You can check whether the parameters do not have any of the default checkboxes checked (one of them is already good). E.g.

If you are not sure you can send your PAN file to support@pvsyst.com. Personally I am not quite confident about giving good advice on modules, but my colleagues should help with that.

[gpuy]

On 11/14/2022 at 9:53 AM, Michele Oliosi said:

Is it a PAN file provided by a manufacturer or a module from the database ?

You can check whether the parameters do not have any of the default checkboxes checked (one of them is already good). E.g.

If you are not sure you can send your PAN file to support@pvsyst.com. Personally I am not quite confident about giving good advice on modules, but my colleagues should help with that.

I´ve realised the problem happens only with PAN files provided by manufacturers (no default checkboxes checked), and it doesn´t happen with PAN files from the database.

Thank you very much for your support, Michele.

Regards, 

Guillermo.