rckeyes2

I'd like to ask a question about how the Bifacial gain can be calculated from PVsyst. I've calculated the bifacial gain two different ways: 1. Toggle bifacial calculation on and off in the "bifacial system" tab of the main "system" tab; toggle from "Use unlimited trackers 2D-model" to "Don't use in the simulation" I've recorded the resulting energy production for a particular project: "Use unlimited trackers 2D-model" results in 44,395 [MWh/a] "Don't use in the simulation" results in 43,114 [MWh/a] Calculate gain: 100*(44,395 - 43,114)/43,114 = 2.97[%] 2. Calculate the Bifacial Gain from the Sankey (Waterfall) diagram: (Global Irradiance on rear side[%])*(Bifaciality Factor)-(Mismatch for back irradiance[%]) = Bifacial Gain [%] Global Irradiance on rear side[%] = 4.94[%] Bifaciality Factor = 0.75[] Mismatch for back irradiance [%] = 0.48[%] 4.94*0.75-0.48 = 3.23[%] I've done this for a few different projects and never get agreement between the 2 methods above. What am I doing wrong here and why doesn't PVsyst automatically calculate the bifacial gain? Cheers, Roger Solidago_1790_Strings_Hanwha_580_BF_equiv_6xSG3600_5.9m_100'_trees_monthly_albedo_CO-2022_VCI-Report.pdf

I've managed to create a .MEF that allows me to import minute-avg data (GHI, DHI, T_amb, WindVel) for about a month of utility-scale performance test data. I believe that minute-avg data is averaged into it's corresponding hour and then converted into a typical 8760 .MET file. I really wish you could import Albedo, POA & IPOA but the model is then, supposedly, over-constrained and IPOA is not even an option in the .MEF process. It sure would be awesome if PVsyst could allow the program to do one month of minute-avg data (Input & Output). 1440 [min/hr] * 31 [days/mo] = 44640. Essentially, your 8760 capability would be upgraded to 44640 capability. But then you would probably have to rebuild the entire transposition model :o The best thing you can do with PVsyst is manipulate the data with Python (or excruciatingly with Excel) and feed 60 qty .MET files to PVsyst through a batch process, treating minutes like hours. Then treat hours like minutes and get your data back into a stable format. To do this right, you also have to do a time shift of each .MET file to avoid needing to interpolate between hour-data of the transposition model. Better luck with NREL SAM :idea: