Aging Tool - Recommended values

[Simon 33]

Hi everyone

I would like to use the aging tool to model 35 years of generation based on Canadian Solar bifacial monocrystalline panel (CS6.2-66TB-H).

Could you please recommend a value for "Av. degradation factor" for such panels?

Does the default value for "Imp RMS dispersion" and "Vmp RMS dispersion" assume any panel replacement during the 35-year project lifetime? My company used string inverter monitoring and drone scan to spot defective panels and replace them. Heavily degraded panels might be moved to the same array and replace by new panels at some point in time. Over the project lifetime, we estimate that up to 25% of the initial panels will be replaced. This strategy shall mitigate mismatch losses to some extent. How can I take this into account in the "Imp RMS dispersion" and "Vmp RMS dispersion" values?

Thank you

Best regards

Simon

 

[André Mermoud]

We obviously don't avail of detailed ageing data for a specified PV module.

The average degradation rate itself is really not well defined. In the literature you can find a wide panel of values (0.3% to 1%/year). The PVsyst proposition of 0.4% seems a reasonable choice for usual modules.  

The specific mismatch effect due to ageing has been developed "theoretically" as a tool in PVsyst, without any experimental basis. We don't know any publication studying this problem in the literature. The hypotheses under this evaluation (Monte Carlo evaluation of the dispersion progress) are purely speculative. 

Therefore this model is obviously not able to take your particularity into account in a reliable way. You can probably take a lower value for the Isc/Vos RMS.