André Mermoud

This is a development that we should do rather shortly indeed. However it is not straightforward, this represents significant work for doing correctly. This will not be in the next main release.

In PVsyst you cannot specify different modules in a sub-array. Therefore you cannot define your systemwithout using Multi-MPPT. Now you can also redefine your inverter as a (dummy) Multi-MPPT device, and define 2 different sub-arrays. In this case you should use the button "Adjust" for correclty sharing the nominal powers of each MPPT input.

In PVsyst and the Northern hemisphere, the azimuth zero corresponds to the south. Therefore your 215° correspond to 35°. Please see our FAQ http://"How is defined the plane orientation ?"

It is extremely difficult to find an algorithm satisfying any situation and anybody. The tables are filled one after the other. If their size is changing, the number of modules on each table will vary and the result will be different for each table. What we could do would be to fill a selection of tables. We will think about that for a next version.

The module area is used essentially for the efficiency definition. PVsyst proposes 2 definitions for the area taken as reference for efficiency: - The rough module size, which gives the "usual" module efficiency, - The cell's area, which leads to an efficiency at the sensitive level, which characterizes the cell's technology (quality). The frame mentioned in the "Table" definition is an extra area representing eventual mechanical supports, which could produce shades on the next table. It is indeed null in many cases.

The Imp and Vmp values are used for establishing the one-diode model. Therefore they affect the PV production of the simulation. Now manufacturers use to take the positive sorting into account by altering the definition of Imp and Vmp. If you account for the positive sorting in the "Module Quality Loss" factor, you will account for this gain twice. Choosing one or the other option is your choice. PVsyst tries to stay coherent and relies to the PNom value for the "official" module efficiency.

This is indeed an error: this verification doesn't apply to the "Lake or River" configuration. This will be corrected in the next version 6.53. In the meantime, there is a workaround: in the "Hydraulic Pumping circuit" definitions, you should choose for Pumping system type "Deep well to storage", modify the parameter "Max. pumping depth" to a high value, and come back to your "Lake or River to Storage" option.

Thank you for your project. I have indeed found the error in the simulation. This affects the way of distributing the losses (some part of oveload is transferred to the efficiency loss), but doesn't affect the final result. I have corrected for the version 6.53.

The definition of the parameter "Limit overload Loss" has been moved to the Project's parameters (button "Albedo&Settings") since a long time. The value in thew Hidden parameters only acts as initial value for new projects.

The spectral effects are not considered for Crystalline modules. They are considered negligible. With amorphous modules, you have indeed an evaluation of the spectral effect, i.e. the deviation with respect to the AM1.5 conditions.

I don't know. Please attach an image of what is wrong.

Importing DXF files is not yet possible in PVsyst. The *.SHD files are meant for internal use, not for public modifications. You can sometimes modify something with some success, but the format has a strict structure suited for the internal organization in PVsyst. It is closely related to the object's defined in the 3D scene and their interactions. It is not possible to describe it in a simple way, and we don't intend to do so.

PVsyst tries to read your data in the american format MM/DD/YY instead of the European one DD/MM/YY. You should specify this format in the Format protocol.

Sorry, we have just discovered an error in the TArray evaluation: the averages of TArray in Daily or Hourly values don't work correctly, as the operating time is not well registered. If you want significant values of TArray, the only way is to analyze them in hourly values (in the CSV file). This will be corrected in the version 6.50.

This tool is behind the button "Miscellaneous tools". This will automatically be apparing on the Report as soon as you correctly define it (no red warning).

The fog is in principle included in the meteo data. There is no possibility of explicitly modifying the meteo data within PVsyst.

In the version 6, the "Module Layout" construction and calculation is based on the 3D shading scene. You cannot add customized shades.

This is also named "Irradiance loss". This represents the beam deficit due to shades. See the help "Project design > Shadings - General" and also "Project design > Shadings > Near Shadings: Main dialog > Shadings treatment of Beam, Diffuse and Albedo"

When the "Minimum voltage for PNom" is specified in the inverter's parameters, this corresponds indeed to an input current limitation. This current limit corresponds to the value I limit = PNom / VmppPNom Now when the Impp of the array is higher than this current Limit, the loss with respect to the available Pmpp is accounted in the IL_VMin loss.

A model for treating bifacial systems will ba available in the next "major" version 6.60, hopefully before the end of this year. However no manufacturer has submitted Bi-facial modules for the database up to now.

This sentence is meant for the irradiation, as the PR is referenced to GlobInc. The PR is obviously related to the temperature. But this is a second-order variation when comparing systems in different locations (same region) or different orientations.

You can use a not-null longitude value. Remember that 1 minute represents less than 2 km. This is completely negligible for the use of PVGIS values.

Yes you can import POA measured values in PVsyst. Please use "Databases > Import ASCII meteo Files", and press F1 for the procedure. The format protocol includes the possibility of reading Global Incident values and PVsyst will perform a retro-transposition.

The difference between Central and distributed inverters is not quite clear. An eventual cloud effect difference is probably completely negligible, as the mismatch between strings under different irradiances (different currents) is very low. In the present time, PVsyst doesn't show any difference between these 2 options, except if you carefully specify the DC wiring losses in each configuration. A difference may perhaps occur because of a mismatch due to the string's lengths in central configuration. This problem is under investigation.

It is no more possible to create a site for your project from the Project's dialog (button "Site and Meteo"). PVsyst now requires that you create and save your Project's site within the database ("Database > Geographical site").