Enginerd

This conversation has been most helpful for me in clearing up that confusion. However, the issue I am now having is that the Limit Overload Loss for Design in the Hidden Parameters changes back to 3% every time I restart PVsyst V6.12 . Any thoughts on why this is? Thanks

Hello, In your FAQ post titled "Why is the Pmpp of my module different than the specified value ?", you discuss differences between manufacturer specified nameplate Pnom and the Imp*Vmp result that PVsyst uses and why this happens. My question is, which value does PVsyst actually use throughout the simulation? If the single-diode model Pnom at STC is higher than nameplate Pnom of the module by a certain percentage, will the simulation output be higher by roughly the same percentage? Thank you.

Hello Andre, I have been playing with thermal loss constants Uc and Uv to address thermal losses in high elevation regions. I ran two simulations where the only difference was Uc and Uv. The second simulation, which had smaller values for Uc and Uv, produced an increased PV Loss due to Temperature (as expected) but is also caused Module Array Mismatch Loss to increase significantly. Can you please give a description of how the thermal properties would affect mismatch loss in the simulation calculations? Thank you.

Thanks Andre, I realized this right before I saw your response.

Hello, I recently upgraded to v 5.59 and noticed a 2% increase in estimated performance for a specific system. When reviewing the system loses between the two runs, the major difference seems to be in the "PV Loss due to irrandiance level" where the newer run now has lower losses. Was there a change in V 5.59 that would modify a module's behavior in low light conditions? Thanks

Hello, I am trying calculate monthly soiling loss as a % using the monthly losses in kWh. I was using the equation (kWh Loss/(kWh Loss + Energy Injected into Grid)). However, I found that if I use this same equation on the Annual Soiling Loss and Annual Energy injected into Grid, I do not get the same % Loss that is in the Loss diagram. In this situation, I have the following annual values: Soiling Loss (from output table): 45255 kWh Energy Injected into Grid (from Loss Diagram): 1289957 kWh Soiling Loss (from Loss Diagram): 3.1% 45255/(45255+1289957) = 3.39% I also tried dividing the loss by the Nominal Array Energy at STC (1627062 kWh), which gave 2.78% Could you tell me what value I should be using to find Soiling Loss as a percent? Thanks