Karjalv

Hello everyone! I'm puzzled. In an hourly simulation output file, I'm having positive values for the global incident irradiation yet the energy injected into the grid is zero for some hours. The loss factors are zero for those hours as well. I'm wondering what is the cause for this? Or is there some kind of threshold value (W/m2) in PVsyst below which energy isn't calculated? Sorry if this has been brought up before. Best regards,

Hi, I just ran a simulation where I set the custom incidence angle modifier to be 1 at all angles, yet I still got 0.2 % IAM losses. Should it be exactly 0 %? Or are the IAM losses affected by some other parameters? Thanks, Vilppu

Hello again! I am now trying to replicate the results of another research with PVsyst. I've created a custom defined profile for the IAM losses in the 'detailed losses' part with the help of a reference article. The reference article itself is: Martín, N., & Ruiz, J. M. (2005). Annual angular reflection losses in PV modules. Progress in Photovoltaics: Research and Applications, 13(1), 75-84. I can send a pdf to an email unless you have access to the article. The model they used is described in the beginning of the article. Now, the results I'm getting with PVsyst are still a little off from the article's values of annual angular losses. I've tried adjusting some of the settings in PVsyst but none of them seemed to have any effect on IAM losses, apart from the IAM curve itself and albedo settings that were kept the same as in the article. (Choosing between Perez and Hay model had some effect, but the difference in IAM losses was only about 0,3 %). Does the model used by PVsyst differ so much of the article's model? Or is there a significant difference between the meteo data? The article used meteonorm data 5.0 whereas PVsyst uses 6.1. Or is there something else I haven't thought of? I'd appreciate any insight! Thank you! -Vilppu

Hi! I'm assisting in a university research related to incidence angle modifiers and dye-sensitized solar cells. We're deciding whether or not to use PVsyst in a simulation related to the research. My question is how is the IAM calculated for the different radiation components (Dp, Bp, Ap)? In the case of isotropic diffuse radiation, I think the effect of the IAM should be included in the same integral with which the Dp component is calculated. Or is the IAM factor calculated afterwards? I didn't find a mention in the help -file about this. I did found this: The bolded part gave me the impression that the IAM doesn't affect the diffuse component at all. I'd like to confirm this so I'll know if we can use PVsyst in the research. Thank you for your efforts! BR, Vilppu