Linda Thoren

Hi, The bifacial model presently available in PVsyst is based on a simplified 2-dimensional representation, with similar assumptions as the "unlimited sheds" or “unlimited Trackers” PVsyst simplified calculation. This approximate calculation may be extended to a 3D scene, provided that this 3D scene is sufficiently well represented by the "Unlimited sheds or trackers". Thus, simply use the option "Use unlimited sheds 2D-model" in your second print screen. You find a tutorial about the bifacial model conditions for the 3D scene below:

Hi, Indeed, today the ground reflection between rows is only considered for bifacial systems. In general, this contribution is very low with sheds and trackers systems, but becomes more important with high tilts and large pitch and crucial with vertical East-West bifacial systems. The calculation of the ground reflection of the front side involves an accurate definition of the ground, its albedo, the geometry, and the full calculation of the ground points view factors. So, the ground reflection of the front side is considered for bifacial systems since all of the needed parameters are already defined, but neglected for monofacial systems. The only way to run a simulation including the ground reflection for the front side for a monofacial system today, would be to alter the PAN file (activating the bifaciality and put the bifaciality factor to 0) and run a simulation with the bifacial parameters, though everything except the ground reflection on front side will be 0 given the bifaciality factor of 0. In the following help page, the reflection on the ground is further discussed: https://www.pvsyst.com/help/project-design/bifacial-systems/bifacial-systems-results.html

Hello, The far albedo in the project settings, will be considered in all projects and correspond to the albedo of the surrounding of the project. The albedo in the bifacial system window is indeed only set for bifacial systems and correspond the the albedo of the ground just underneath the modules. This is not necessarily the same as the far albedo of the surrounding. Kind regards

Hello, You should define the number of lines to be skipped, before the line where the (sub)hourly data starts. The general procedure for importing a custom weather data file is described in the following link: https://www.pvsyst.com/help/meteo-database/import-meteo-data/custom-meteo-files/conversion-protocol.html Note that you in this tool are supposed to import a a .csv file with (sub)hourly data, thus one line per time step with irradiance and temperature data and convert the .csv file to a .MET file that you can use in PVsyst to run your simulation. It seems like your source file is already a .MET file with Meteonorm 8.2 (hourly) data. You cannot re-convert an hourly .MET file to include the clipping correction.

Hi, The shading calculation is indeed explained in the second link you have attached. In general, the higher the tilt, the higher the albedo contribution. Most of the albedo contribution will directly be lost (you see that the albedo loss is indeed following the albedo contribution) since we assume that only the first row is "seeing" the albedo, so that the albedo shading factor will be (n-1)/n (n = number of sheds). The albedo loss is a significant contribution to the global shading losses.

The low light performance and temperature coefficient is defined in the individual .PAN files. The thermal parameters are then set for the full system to evaluate the temperature and the thermal losses in each sub-array. Thus if you are mixing panels in the same inverter (though in different sub-arrays), the different temperature coefficient of the different modules are well taken into account. In the loss diagram you will see the results for the full system. You find more information on the subject in the following PVsyst help pages: https://www.pvsyst.com/help/physical-models-used/pv-module-standard-one-diode-model/index.html?h=pv+module+standard+one+diode+model https://www.pvsyst.com/help/project-design/array-and-system-losses/array-thermal-losses/index.html

Hello, As you indicate, in PVsyst you will first find the irradiance loss (linear shadings) and then the additional electrical shadings. Note that, in the loss diagram, each loss is defined as percentage of the previous energy quantity. Therefore the percent values are not additive.

Hello, With lower PV production due to ageing modules, it seems reasonable to see less overload losses.

You define the year in the batch parameter csv file. As in the video tutorial un minute 7. Now indeed it seems like you are not varying any of the parameters and simulate the same project 25 times.

Hi, It seams like you have set all the simulations for year 1. In the 15th column "Simulation Year"

Hi, You find information of how to define the ageing in the following tutorial: The Batch mode is described in the following tutorial:

Hello, When using the independent MPPT inputs feature, it is very important to have a multiple between the number of strings and MPPTs in each sub-array, or PVsyst can not equally distribute the strings over the MPPTs and you risk incorrect evaluation of the inverter losses over nominal inverter power. The MPPT and Power sharing feature is fully described in the following youtube tutorial:

Hello, This depends on your system layout. If the majority of the shadings are regular mutual shadings, you can leave the fraction for electrical effect to 100%. If you have several shading objects in the scene causing irregular shadings, you might need to adapt this value. This is furthered discussed in our help: https://www.pvsyst.com/help/project-design/shadings/electrical-shadings-module-strings/index.html#module-layout-reference Kind regards

The last generated Monte Carlo values is for year 30. You can still simulate a degradation beyond this, though after 30 it is assumed to be a linear trend.

In the coming PVsyst version 8.1, several input parameters can be defined as hourly values via a .csv file. This will allow snow coverage (in %) to be specified on an hourly basis if desired. However, we are not currently implementing more advanced snow-coverage models, though this is on our roadmap for a future version.

Hello, If you for instance have self-consumption or storage, System production production is not necessarily the same as E_grid. What version of PVsyst are you using? There may be differences due to rounding of results when saving files. However, these differences are necessarily negligible. If they are not, there may indeed be a problem and feel free to export your project as a zip file and send us an email to support@pvsyst.com

Hi, The Monte Carlo values are currently generated for up to 30 years. For simulations extending beyond 30 years, a linear trend based on the last two data points is applied. Thank you for your feedback. I’ve noted the interest in generating Monte Carlo values over a longer horizon and potentially this can be developed for a future version.

Hello, 1. In version 8.0.19 we have been improving the orientation grouping function. Which version are you using? What tolerance is set in the project settings? 2. The issue could from the fact that you can define multiple gaps for your tracker in PVcase, motor gap, joint gap, horizontal gap between modules and vertical gap between modules (though normally this would lead to the opposite issue, that more modules are placed in the 3D scene than in the system definition). PVsyst we handle only horizontal gap between modules and vertical gaps between modules, so the PVC file doesn’t contain the other information. The PVC file only contains the total length/width of the trackers and the horizontal/vertical gaps between modules. Did you check the "Terrain following trackers" checkbox in the "Frame creation" tab in PVcase? This setting should break the PVcase trackers into multiple smaller trackers for PVsyst (according to the defined gaps), placing the modules at the correct location. In this case, PVsyst will divide the tracker where the motor gap is. I also notice that 163 tables are not defined by modules, potentially the mismatch comes from these tables. Kind regards

Indeed this is a limitation we still have. The electrical shadings in general in PVsyst are further explained in the following video:

Hello, At the moment, small shades at the center of pv modules are not treated and do not create electrical shadings. This is something we hope to improve in a future version. Kind regards.

This is not a precise science and can be site dependent. In order of magnitude, one could consider that a site within 10km distance can use the same .MET and .SIT without issues.

In the detailed losses window, you can set 1% for the first year degradation as a LID loss in the "Module quality - LID - Mismatch" tab and 0.44% as an average degradation factor in the Ageing tab.

Dear Diana, You can generate graphs and plots through the detailed results window (pre defined graphs or hourly graphs for a large amount of simulation parameters). In the Advanced Simulation window, you have additional freedom to create custom plots that also can be included in the report. Another possibility is indeed to create an Output file with the relevant parameters and do the analysis in an external tool. Kind regards

The bifacial model presently available in PVsyst is based on a simplified 2-dimensional representation, with similar assumptions as the "unlimited sheds" or “unlimited Trackers” PVsyst simplified calculation. This approximate calculation may be extended to a 3D scene, provided that this 3D scene is sufficiently well represented by the "Unlimited sheds or trackers". You can read more about the bifacial model conditions in the following help page: https://www.pvsyst.com/help/project-design/bifacial-systems/2d-bifacial-model-conditions.html With multiple orientations and sub-systems with different table width, you can in version 8 create new "orientations" in the orientations window and group all the tables with similar characteristics in a sub-system/orientation, and apply the bifacial model to each sub-system in the system window

Hello, You find a full explanation and a summery of common cases in the following PVsyst help page: https://www.pvsyst.com/help/project-design/shadings/electrical-shadings-module-strings/partition-in-strings-of-modules.html?h=partitio#up-to-748