Chen

OK，thanks！

Dear PVsyst team： I saw an article in the literature that mentioned a comparison between the settings of UC and UV and actual simulation tests. Can we see if there is still a need to optimize UC for bifacial modules？ thanks de Oliveira A K V, Braga M, Naspolini H F, et al. Validation of Thermal Models for Bifacial Photovoltaic Systems under Various Albedo Conditions[J]. ESS Open Archive eprints, 2024, 63: 06323163. https://onlinelibrary.wiley.com/doi/abs/10.1002/pip.3892 CTG_PIP_Temperature.pdf

OK IRev = Iph +aRev *V，for aRev=800mA/V^2, 800/1000*（-5.2）*（-5.2）= 21.632 (A) ；the externally forced current is 7.93A； how to calculate IRev？ thanks

Excuse me, Prof.Andre Mermoud is I the reverse current in this formula，so a more accurate representation would be IRev = Iph +aRev *（V+Rs * IRev） ；and the externally forced current is IRev？ thanks for reply.

as we can see the three values on the figure， the V (-5.2V）,I（7.93A） and P（128W），Is there a formula that can explain their relationship，thanks！

Dear pvsyst team： I am using this software to simulate the temperature and power when a cell is local shading. I find that “externally forced current= 4.4A” is all the same for the different solar modules. What does it mean？ thanks！

sorry ，i find a mistake in my sentence，the solar size is 210mm*105mm，so final result is 44/ ( 0.21*0.105*29) =25 = 94 （℃）.The results are basically the same as those of pvsyst.

just choose "Generic_Mono_700W_Half_Bifacial.PAN" for example. Here, Uc = 29 W/m²·k, or say Uc = 29 W/m²·℃, and the size of the cell is 150 mm*210 mm. For one solar cell shading, if the temperature rises by 1 ℃, it need power 0.21*0.15*29= 0.9135（W），and the cell power consumption now is 45W，45/0.9135= 48.17 （℃），by adding 25 ° ambient，the result is 73.16（℃），which is not quite consistent with the results shown on the graph （95℃）.Can you help me check if there are any errors in my deduction？ thanks

in my opinion，the module VOC corrected by irradiance value and ambient temperature will be more reasonable for system design.

Dear PVsyst team： when some solar cell is partial shaded，how to calculate its temperature as shown in the following figure, thanks!

Hi PVsyst team: Did we do some studies about the temperature and convective heat transfer characteristics of PV module due to the different array pitch，or different array tilt angle，or fixed tilted installation horizontal axis N-S installation. such as the pitch of 1# array is 4.5m, and the pitch of 2# array is 5m, in my opinion, the Uc and Uv coefficient will be different for the two array modules. meanwhile，choosing different sopport for photovoltaic modules can also have an impact on the temperature of the modules. Will future software consider these intricate factors？ thanks

Thank you very much for your help Regards!

"Imp RMS dispersion are not comparable to a degradation factor. You should first translate into a degradation of the Pmpp. This is done stochastically by PVsyst". sorry, I still feel very confused for this topic. Can you clearly tell users how to operate and take values of Imp RMS dispersion ? Should we take 0.4% by default or other values for Topcon or HJT /IBC different solar modules？Or is there any relevant basis to support filling in this data. thanks!

The Average degradation value obtained from the the module warranty interface is 0.38%/ year. Is 0.38% used in the PV module ageing parameters input settings interface？should we change 0.35% to 0.38%？thanks!

OK，we assume that the degradation given to the user is achievable, that is, in the first year, each solar panel power degradation will not exceed 1%, and starting from the second year, the maximum degradation per year will be 0.35%（the minimum degradation is 0%）. According to the upper limit of warranty. "maximum average degradation factor"="1/2 of yearly warranty"="0.175%", right？ So at the end of the first year, the minimum power of the module is still 99% of the initial level, and at least 98.65% at the end of the second year, can the average degradation rate from the second year be equal to 0.35%? The worse possible annual degradation rate we assumed in the warranty is 0.35%. "Average degradation factor"+2*"Imp/Vmp RMS dispersion" ＜ "The worse possible annual degradation rate (the upper limit of warranty is 0.35%) " ； so that "Imp/Vmp RMS dispersion"="0.0875%" ，( 0.35% - 0.175%)/2= 0.0875% Thanks for your time!