dtarin

Perez is the standard in industry. See additional posts here: https://forum.pvsyst.com/viewtopic.php?t=4596

I cannot say, in my test (v6.84) there was no change to GlobInc. In a fixed tilt system on flat ground (no terrain), the only parameter that will affect GlobInc is system tilt if I recall correctly.

https://forum.pvsyst.com/viewtopic.php?f=30&t=483&p=2124&hilit=perez#p2124 https://forum.pvsyst.com/viewtopic.php?f=17&t=477&p=2104&hilit=perez#p2104 https://www.pvsyst.com/help/models_meteo_transposition.htm?zoom_highlightsub=transposition

Yes, just overwrite the constant loss factor Uc under Field Thermal Loss Factor in the Detailed Losses menu.

Yes it is possible. Under batch settings you will select specify different meteo files under parameters selection. Then use the batch file which is created and modify it so that it includes 20 lines in your case for each meteo file.

It depends on the transposition model you have selected for your simulation. The Perez transposition model is the default for PVsyst, and that is where you will find the formula for converting GHI to POA

Is there terrain? Fixed tilt or tracker?

If i recall correctly to set PV materials you need to use google sketchup

What is the nature of your shade scene? Is there terrain and/or other shading objects? Are you modeling in unlimited sheds or with a 3d shade scene?

PVsyst POA is dependent on your weather file, location, and system design. There are a lot of questions one could ask, such as how well does your PVsyst model match actual site conditions, is there complex terrain for this site in question? If you are comparing measured to modeled and the results are way off, then perhaps you have an inaccurate weather file. Does GHI/DHI in your model match measured? If it doesnt, you shouldnt be expecting GlobInc to match measured. If your weather file is TMY, that is a P50 weather file.

https://www.pvsyst.com/previous-versions/ Find version that will work with the met file you have, install as parallel installation. Did you first try just dropping the file or importing the MET file first? Open 6.8, select file > import components, find your MET file, import.

If you can't directly drop it into 6.8, import it into an older version of PVsyst (create a project) then export the project . Then import the project into 6.8. You can install an older version of PVsyst as a parallel installation and use both versions of PVsyst if you only have 6.8 currently.

Versions 6.8x cannot be used in earlier PVsyst versions. If the there is no version incompatibility, just drop the .met file into your meteo folder: C:\Users\COMPUTERNAME\PVsyst6xx_Data\Meteo

I dont believe there is a maximum size you can simulate. The main constraint would be the processing time or ability of the hardware/software to model a large site in the 3D shade editor.

The bifaciality factor is a property of bifacial modules. They are modules which receive light from both sides of the module, and have either glass or a transparent backsheet on the backside of the module. The bifaciality factor refers to the ratio of the efficiency of the rear side compared to the front side efficiency. Typically manufacturers will provide PAN files specific to their bifacial modules. If you are not modeling specifically a bifacial system, you should not use this feature.

I dont think those files are meant to be imported into PVsyst. They must be imported into meteonorm software, which will generate a horizon file based on your site location, and that horizon file will go into PVsyst.

Hello, If the OND file was properly updated to include a temperature de-rate, please verify your weather file contains temperatures during production hours which are higher than your de-rate in order to see temperature-related clipping. Assuming this is an outdoor installation, the inverter temperature for nominal power evaluation should be checked to external ambient temperature (which is default) for grid-connected systems. Miscellaneous tools is renamed to Energy Management in new PVsyst versions.

To add to this suggestion on the same feature, it would be helpful to edit the perimeter of the extruded poly in the shade scene and not in the separate menu. Ground images are brought into the shade scene and the extruded polygon is used for obstructions. When the layout changes, the polygons have to be redrawn.

Hello, It would be helpful if PVsyst were to modify the data which are imported from an NREL TMY file to included relative humidity.

Hello, I have a question on PF implementation and thought I would keep it in this post. I have a Power Electronics central inverter which requires a 0.97 lagging PF. In PVsyst, do I select "limit in active power", or "limit in apparent power" on the "Grid Power Limitation" tab? Inverter Pnom is defined as apparent power.

I dont believe it is contradictory. Simply deleting the file does not change the already existing SIT data in the PRJ/VCi. The SIT data is stored in the variant and project file (you can see this in text editor) . If the project is updated with new site data and the simulation variant is saved, the variant/project will update with the new values. You can delete the SIT file and still run because there is still the site data in the PRJ/VCi file. I just tested changing the site file, and checking in text editor the PRJ and VCi files. The update to contain the new data. edit: I see the error I wrote; in a way it is backing up the SIT file, so yes that was incorrect. Edited for correction. However MET files need to transfer with projects.

NSRDB ground station data is a bit old, and varies in uncertainty (Class I-III, with III having highest uncertainty). Class II-III are generally not used due to the uncertainty and quality of data. However the other issue with this source is the proximity of these stations to your site and how representative it might or might not be. PSMv3 compared to some commercially available satellite data providers (for TMY data) has been quite high in GHI in my experience (3-6%). You are able to select your location however, which is a benefit compared to NSRDB. Perhaps look at both and consider the result might be somewhere in between the two (NSRDB is often lower GHI compared to PSMv3 and other sources).

The PRJ does not backup MET. If a project is transmitted without the MET file, you will not be able to run the project with the same meteo source. Also, it stated that the variant stores SIT data (not MET data), and not the PRJ file. But when viewing a PRJ and SIT file, both contain SIT information. If a SIT or MET are updated, and the PRJ/SIT are saved, the next simulation will run with the updated values. This is easy to check. Pick a location for your site next to a steep hill or mountain and run with a site file on the low ground and high ground. Your elevation will update in the report, and also if the coordinates change more than two decimal places, they will update also. Another check is to use the PVGIS horizon feature with two different SIT files. This function pulls coordinates from those listed in the SIT file.

P = I*V, so 91,000 W/400 Vac = 227.5 A

That article is quite old. Perez is the default transposition model. Using measured diffuse irradiance will result in higher transposition accuracy for GlobInc.