All Activity

Hello, With a grid connected system with self-consumption, you can un-tick the option "Allow solar injection into the grid"

WHAT DO I SET IN THE PROGRAM TO HAVE A PV WITH ZERO INJECTION INTO THE GRID?

Hello. Unfortunately, this approach has a fundamental limitation: PVsyst treats the ground surface as a diffuse reflector, meaning it only models albedo (reflectivity intensity) but not the directionality of the reflection. A real physical reflector tilted toward the panel's rear face would redirect light in a specific direction, which cannot be accurately replicated by simply raising ground points. Therefore, this workaround would not faithfully simulate your intended reflector behavior.

Hi, thanks for your replay You mean BkVFLss * GCR = BkVFLss_refers_to_ground? I checked these variables relationship: GlobBak = ReflBck + DifSBak - BackShd （assume BeamBak = 0） But what is relationship among ReflBck, BkVFLss_refers_to_ground, ReflLss, GlobGnd?

Hello. There is the posssibility to raise specific points in the 3d construction on the ground to immitate slopes. Maybe we could use this feature to create a sloped surface (immitating a reflector) in order to see if its possible to increase bifacial efficacy. Is that possible? I am currently working on my thesis to compare specific performance improvement methods for photovoltaic systems, and one of them is to add a special reflector with an albedo of 0.7 behind a PV table. This reflector is impossible to be added in PV syst and therefore I am trying to immitate it.

Hello, The P50-P90 statistical estimations are based on yearly values and thus it is not possible to generate monthly values through PVsyst. You can read more about the P50-P90 evaluation in the following help page: https://www.pvsyst.com/help/project-design/p50-p90-evaluations.html?

Hi, The reason is that GlobGnd, DiffGnd and ReflLss are variables that refer to the m^2 of ground area. Whereas, BkVFLss refers to the m^2 of PV modules. If you were to mutiply by the respective surfaces (ground surface > module surface), the energy hierarchy would make sense.

This is what GlobGnd and GkVFLss described in PVsyst help GlobGnd Global incident on ground, below the system. ReflLss Ground reflection loss (albedo) BkVFLss Loss due to the view Factor for rear side So I think GlobGnd is source energy for other parameters such as ReflLss and DiffGnd etc. That means value of GlobGnd should be the largest during these parameters. But I processd some simulation and looked into details of results. I found that BkVFLss always larger than GlobGnd. Does anyone know why about this? GlobGnd DiffGnd ReflLss BkVFLss kWh/m² kWh/m² kWh/m² kWh/m² January 26.1 9.94 13.06 18.8 February 41.5 13.76 20.73 35.4 March 70.9 23.17 35.45 67.1 April 98.7 27.04 49.34 96 May 125 28.2 62.51 121.1 June 124 29.7 62 119 July 122.1 32.43 61.07 117.3 August 103.1 31.35 51.56 99.9 September 75.3 24.16 37.64 72.3 October 52.8 18.7 26.41 47.2 November 30.3 12.88 15.13 23.6 December 20 10.03 10 14.4 Year 889.8 261.35 444.88 832.2 albedo=0.5 GlobGnd=889.8 BkVFLss=832.2 GlobGnd DiffGnd ReflLss BkVFLss kWh/m² kWh/m² kWh/m² kWh/m² January 26.1 9.94 5.22 30 February 41.5 13.76 8.29 56.7 March 70.9 23.17 14.18 107.4 April 98.7 27.04 19.74 153.6 May 125 28.2 25 193.8 June 124 29.7 24.8 190.4 July 122.1 32.43 24.43 187.7 August 103.1 31.35 20.62 159.9 September 75.3 24.16 15.06 115.7 October 52.8 18.7 10.56 75.5 November 30.3 12.88 6.05 37.7 December 20 10.03 4 23 Year 889.8 261.35 177.95 1331.5 albedo=0.8 BkVFLss=1331.5

Hi everywone. Please tell me if it is possible on main rezults page to get yearly results -month by month with P75 figures. As default it shows P50

Hi, I have the following limitations from the grid: Import: capacity: 150 kVA, power factor: 0.95 lag to unity Export: capacity 15,000 kVA, power factor: 0.98 lead How should I introduce this in PVSyst? Should be 15 MVA and PF 0.98 lead or 15MVA and PF 0.95 lag? Thanks.

If bifacial is disabled, the variables will not be available, same for the horizon loss.

Hello Vatsaa, Thanks for your post. It could be a network problem, also could you check that your machine time's is set automatically ? Finally you can send us some logs at support@pvsyst.com . Regards, Laurent

Hi We are working on a project that needs certain parameters in the 8760 (image attached) GlobBak (Global irradiance on the rear side) and FHrzGl (Horizon shading factor on global) does not show up in the 8760-csv file. Is it due to the bifacial model being disabled as projects are canopies, and if there are no far shading losses for the project? FHrzGl only does not come up for the sites where far shading losses are zero. I just wanted to confirm before responding to the client

Dear PVsyst Team, While importing new geographical site parameters, it is not able to locate the site in the geographical site parameters tab; the map becomes black and is not able to locate the site location. Is this a bug or anything we need to change in PVsyst to make it like before?

We update the database using the requests of the manufacturers, and publish it with each new release of PVsyst. We can't of course follow all the new products of all manufacturers in the world. We don't want to include data without the acknowledgement of the manufacturer. Nevertheless you can easily create your own components by yourself. The easiest way is to choose a similar existing device in the database, modify its parameters according to the manufacturer's datasheets, and save it under a new name, therefore creating a new file in your database. You have a tutorial for that on youtube: https://www.youtube.com/c/PVsystTutos.

DiffGnd definition missing from documentation.

Hi, I'm trying to get the .pan file of the ZNShine, ZXM7-UHLDD144 595W module. Not having any luck with the manufacturer, if it's not too much trouble could someone please provide it if they have it. Thank you so much

Hello, Yes with different weather data sources the production will vary, since the irradiance data will vary. You find more information about the weather data providers and a comparison in the following PVsyst help page: https://www.pvsyst.com/help/meteo-database/import-meteo-data/data-source-comparison.html

Funny, I just added this in the help of our 8.1 candidate a few days ago. Hence sure, will be present in 8.1 🙂 Indeed, that is the correct citation.

Hi, I conducted a study on hourly values for a solar power plant (SPP). I compared two different meteorological data sources. Meteonorm shows higher production in the morning than PVGIS, while PVGIS shows higher production in the afternoon than Meteonorm. Why are the production values different? Meteonorm (kW) PVGIS(kW)

Could you please add the formal citation for the Hay transposition model to the PVsyst Help References? It would be very helpful to have the primary source explicitly listed alongside the other physical models at these locations: V7: https://www.pvsyst.com/help-pvsyst7/index.html?references.htm V8: https://www.pvsyst.com/help/references.html My assumption is that it is the following citation (IEEE format): J. E. Hay and J. A. Davies, "Calculations of the solar radiation incident on an inclined surface," in Proc. 1st Canadian Solar Radiation Data Workshop, 1980, pp. 59–72.

You can download time-series data (20+ years) from https://nsrdb.nrel.gov/data-viewer. From there you can calculate it manually from GHI or import each year into PVsyst. You can also get ~18 years of data at PVGIS free https://re.jrc.ec.europa.eu/pvg_tools/en/#MR.

This tool is meant to compare .MET files, you first need to create several .MET files using different data sources

Hi, I tried with the second link to stimate a location but I coul not get an output. What should I do?

Thank you for the report. Note that this bug was corrected in PVsyst 7.2.17 https://www.pvsyst.com/help/release-notes/index.html#exec-1--version-7217