André Mermoud

Please check that your inverter is correctly defined. This usually arises when the efficiency curve is not well defined.

As explained in the help, in PVsyst you should import the file "Obstruction Elevation" for import in the Horizon tool. However the "Far shading" loss is of course closely related to the horizon line you have imported. You can check that this horizon line as imported by your SunEye is correct, by measuring the altitude angle of some points of your profile (on site). NB: The Solmetric horizon profile will also include the near shading objects. The shades of near objects should not be evaluated by the "Far shadings", but by the "Near shadings" part of the software. Therefore you have to remove their contribution in the Solmetric profile if any (i.e draw a line of the "Far" horizon only).

This is not a problem of import, but just of display on the tables. The values in the program are not truncated. However decribing hourly values of irradiance with 0.1 W/m2 resolution doesn't make sense, as the measurements have a much higher uncertainty. The same holds for ambient temperatures specified with 0.01°C. Did you ever try to measure an ambient temperature with a thermometer ? Even with 1°C resolution the value will not be stable over one hour ! NB: The rounding errors of measurements are always randomly distributed: the variance on several measurements goes with 1/sqrt(n) (n = number of measurements). For one year (8700 values), this becomes 0.01 times your uncertainty interval.

The "Module Layout" part is not suited for such big systems. It should no be used for systems greater than 500 kW or 1 MW at most. See our FAQ With my big power plant, the calculation time is prohibitive.

The Ohmic loss is quatdratic (R * I**2). Please see our FAQ How to determine the wiring loss parameter?

Yes of course, PVsyst is able to perform simulations with arrays specified for 1500V or more (without limitation). However up to now, most of the devices were limited to 1000V. The limitations are at 2 levels: - The inverter definition: few inverters are specified for a Maximum voltage greater than 1000V. - PVsyst will forbid using a system voltage greater than the maximum voltage specified for the PV module. Almost all PV modules are specified for running in Arrays which don't overcome 1000 V (IEC specification). However you have more and more PV modules certified for 1500V in the PVsyst database. This limitation is in the PV module's definition, page "Size and technology", item "Maximum voltage IEC". If you want to modify this value, it is under your own responsibility on the field. The choice of IEC or UL limit during the sizing process is in the project's definitions "Albedo and Settings".

In both module, you have the same parameters (namely Rserie and Rshunt) and therefore the muVco calculated by the model is identical. NB: The muVco value slightly varies with these parameters, especially Rserie. But in your export to EXCEL, the column muVco corresponds to the value specified by the manufacturer. This value may have been specified differently. See our FAQ How to adjust the Voc temperature coefficient ?

I'm afraid that you have completely misunderstood this little visual tool. The blue line represents the PV module plane (as seen from the prolongation of the axis). The green branches are the normals to this plane. As anywhere in PVsyst, red dots are for dragging with the mouse. You can play with the red dots for setting the stroke limits, and then orientate the PV modules between these limits as you like.

Does the program crash or hang ? If it crashes, please send a screenshot of the error to support@pvsyst.com. If it hangs up, it is probably being computing. Please see our FAQ With my big power plant, the calculation time becomes prohibitive

C:\Program Files (x86) is the space reserved by Windows for the installation of programs. You cannot write anything here. By default when using PVsyst for the first time, the workspace of PVsyst (named \PVsyst6_Data\) is located in your personal working area, usually named "My documents" (or something like this). Now if you have really worked with this workspace up to now (perhaps it was allowed by Windows formerly), Windows has displaced your data, and you will retrieve them in your personal working area, in a directory named "c:\ Users \ User \ AppData \ Local \ Virtual Store \ ProgramFiles \ PVsyst6.0.6 \ PVsyst6_Data" (see our FAQ I don't find my files in the Data structure) You should create a new data structure \PVsyst6_Data\ in your personal area (using button "New" in the Workspace dialog), and displace your \VirtualStore\ data here.

The time of your data are probably not matching the time of PVsyst. And you have probably not followed the advice of PVsyst for checking the data quality when importing your data. Please analyze your meteo file in "Databases > Meteo Tables and graphs", page "Check data quality". Here you have performant tools for the analysis of your imported data, and you can press F1 for a complete explanation in the help.

For the angle's definitions, see our FAQ How is defined the plane orientation ?. The azimuth angle is your choice according to the environment of your installation. Now if you want to identify the best angle - or the loss you will have if you are not at the optimal angle - you can use: - either the little tool in the orientation dialog (button "Show optimization") for a quick but rough estimation. - or the dedicated tool "Tools > Transposition factor", where you can get better estimation, taking eventual Horizon or periods for optimization into account.

For comparing differences bvetween equivalent simulations, you should compare the "Loss diagrams", which will show exactly what is different in the behavior of your systems. In your case I can see 2-3 possible causes: - If the ambient temperatures are not the same, the Temperature losses will be different. - If the Diffuse component is different, the result of the transposition may be different. - If the Irradiance distributions are very different, the Irradiance losses may be different.

This depends on your system layout, especially on the shadings. If you have a system without regular shadings (not a "row" or "sheds" system), you can use "Databases > Tools > Transposition factor". If you have a system in sheds, the shading losses deeply modifiy the optimum. In the "Orientation" dialog, you can see "Unlimited sheds > Show Optimization", and here presss F1 for getting an explanation.

In PVsyst the time labels always represent the beginning of the interval. 11H represents the average of the 11h to 12h values.

I don't know. The Shading objects should be defined as such in the Helios3D program. It is a specific definition in their output file. Now there may be a "youth" problem with this import. Please send your Helios3D file (*.h2p) to support@pvsyst.com.

If there is a red warning on the blue top right panel, the Model page is indeed not available. Now since version 6.39, there is indeed the possibility that the Rserie or Rshunt definitions produce a read warning, and this will hide the panel where you are defining these quantities. This is indeed a bug to be corrected. However you can: - either define these parameters using the "Show optimization" dialog (bottom left button). - or start from an existing module and modify its parameters.

When watching the report in the dialog of the "Report" button, ypou have an option "Units".

You have not defined the Filename for each hourly files (*.CSV).

PVsyst doesn't treat this behavior in the present time. I have not seen much inverters with these characteristics up to now. During the simulation, PVsyst clips the voltage at the limit value, and therefore displaces the operating point on the I/V curve, leading to losses with respect to the Pmpp array possibility. So that the efficiency limiting is related to the PV module's properties rather than a special inverter behavior. The results should not be very different. For the lower voltage, the "Minimum voltage for PNom" represents indeed an input current limit. The limit current is indeed Pnom / VMinPnom. When the array MPP voltage is below this limit, the inverter works at this fixed input current on the P/V curve.

The formula is mentioned in the Help "Project design > Array and system Losses > Array thermal losses".

The times when this arises are very close to sunrise or sunset. For these hours including the sunrise (or sunset), PVsyst considers the time between sunrise and the end of the hour, and computes the solar geometry at the middle of this interval. The Direct normal is computed on the basis of the GlobHor, DiffHor and divided by the sin(sun height). The cut on Sun height is rather low (I dont remember the value). But there is a cut of 10 W/m2 on the GlobInc value for the rest of the simulation. Now for your tracking situation (probably with backtracking), the plane is almost horizontal (1-2 degrees) so that the GlobInc value is very low at sunrise. On the other hand, there is a cut on the incidence angle (>88° doesn't make much sense due to the IAM loss). This explains the null values of BeamInc.

This is indeed a very difficult task. Our IT specialist has already passed some hundreds of hours on this development. Some parts of the calculation are now "threadable" without error. However there are still ununderstood bottlenecks and we don't gain any significant time.

This tool "Long term Financial Balance" has indeed a parameter "Annual Production reduction" (expressed in %/year). Here, if you click the button "Graphs" - "Table", you will see a column for the sold energy yearly revenue. However the simulation results are for the first year (except if you take the ageing into account in the "Module Quality Loss").

The database is updated with each new version, according to the requests of the manufacturers.