Dong

Sorry it was my bad, I didn't make my idea clear. Indeed RMS dispersion describes how wide the span is, where modules will randomly degrade the Imp or Vmp by means of Gaussian distribution. Therefore, I made the proposal that the range of "-2*RMS to 2*RMS" (as known as "-2*sigma to 2*sigma") is quite sufficient to represent 95% of modules. So that the total distribution range can be controlled as "4*RMS*operation years" wide. Since module manufacturer can make the power warranty of 0.4%/year for any of the module, the degradation only will be happened inside the range of "0-0.4%*operation years" (e.g. 0-0.4% for 1st year, 0-0.8% for 2nd years). So that If I make the proposal that 95% "Guassian distribution range" equals to "module warranty range", I can draw the conclusion that the "4*RMS*operation years" equals to "0.4%*operation years". So that "RMS"="0.1%/year". Hope the following table can explain the logic I mentioned above. Thanks for your time in advance! BR, Dong

Thanks Prof. Andre! Since most of module supplier can warrant the maximum degradation of 0.4% for every TOPCon module, it can predict that the degradation of all modules can be controlled within the span of 0-0.4% after 1 year operation, 0-0.8% after 2 years operation, and so forth. Therefore, inside the Guassian distribution, I would say the inrerval of "-2*RMS to 2*RMS" shall equals to the warranty span I mentioned above. Because module supplier (I'm from LONGi) doesn't have the sufficient data to indicate the "Average degradation factor", "Imp RMS dispersion" and "Vmp RMS dispersion". Can I make the hypothesis that: 1. "Average degradation factor"="1/2 of TOPCon yearly warranty"="0.2%", 2. "Average degradation factor"+2*"Imp/Vmp RMS dispersion"="0.4%", so that "Imp/Vmp RMS dispersion"="0.1%" Please correct me if my understanding is wrong, or my hypothesis is not reasonable. BR, Dong

Hello, When I was doing the PVsyst simulation and inputting the parameters in the aging tool, I read the help manual and got to know that PVsyst has supposed Gaussian distribution with Imp and Vmp RMS dispersion value. According to the help manual, by considering the 2*"RMS dispersion", it is applicable to 95% of the modules. It is well known that 2 sigmas in the Gaussian distribution equals to 95% of the hits. Does it mean that "RMS dispersion" of Imp and Vmp can be treated as the "sigma" for Normal distribution? Looking forward to your kind reply! BR