André Mermoud

This has been fixed in the version 6.60.

We will not create a "Major" version 7. Our policy is now to improve PVsyst progressively, in an incremental way. Now the import of Sketchup and AutoCAD files is now possible in the version 6.60 (considered as a "Major" version by the introduction of a professional tool "OpenGL" for the 3D editor).

In the present time, you have the choice of taking the losses into account either before or after the transformer. We are deeply renewing this feature, and this will be improved in a next version.

The Inactive band is the extension of the mechanical structure, with respect to the PV module itself. NB: the bottom Inactive band is not significant in the "Unlimited sheds" calculation: the mutual shadings begin when the bottom of the PV modules become shaded, whatever the bottom inactive band.

The power derate of PNom(ac) as function of the temperature may be specified in the inverter's definition. The fan's consumption should be specified as "Auxiliary Loss" (in the "Detailed losses part). The inverter temperature conditions during the simulation may be specified in the "Miscellaneous tools" part.

This is corrected in the version 6.61.

In PVsyst V 6, you can define up to 8 orientations. In the version 5, this was limited to 2 different orientations only.

In PVsyst you can define sub-arrays for at most 8 orientations. However this is not possible with stand alone systems yet.

The pitch is the distance between identical points of 2 rows (for trackers: from axis to axis, for sheds: from base to base).

You can read my previous post, and also our FAQ How is the database of PVsyst updated?

Sorry, there is no progress with this in the present time.

As explained in the FAQ, the maximum voltage is the voltage on the I/V curve, when the voltage point corresponding to the PNom(Input) of the inverter is lower than the VmppMax of the inverter.

Please see the Help "Project design > Array and system losses > Array Thermal losses". However with a spacing of 3 cm, you don't have any air circulation and heat exchange (or a negligible one), and you can consider your PV array as back insulated.

If you have a little object's shade on a rather big PV array, the shading effect ,ay be very little. You can see it in particular situations with the "Animation" tool. If the annual shading effect is lower than the resolution of the percentages in your loss diagram, you will obviously not see it.

The Table width is a backtracking parameter, which should be identical for all trackers, as it is used in the backtracking calculation. If you pass from Landscape to Portrait, the table width is probably different, so that the backtracking calculation will be different. This is not possible in PVsyst where only one tracking orientation is possible. Now you can probably simulate your system without backtracking, which seems to be not suited for your project (especially if you have altitude differences between your trackers).

The specification of a percentage is just an indicative way of specifying the wiring loss (for showing an order of magnitude when designing your system). The real parameter used in the simulation is the Wiring Resistance, which is either specified explicitly or estimated from your choice of a percentage in STC conditions. The energy loss is calculated at each step of the simulation, as Rw * I².

Yes, this feature is implemented since version 6.27. In the inverter's derfinitions, please see the page "Output parameters".

Please compare the Loss diagrams for understanding where are the differences. Now in some very rare cases, it seems that the first simulation of a new variant doesn't take all the specified parameters into account. However we cannot fix the problem, as we have never reproduced it in our installations. It seems that this was only arising with rather old versions of PVsyst.

See our FAQ Why sometimes the overload losses increases significantly without reasons ?

The shading calculation is a geometrical calculation as function of the sun's position. The program doesn't calculate the optimal distance between strings, as there is no optimal distance. This is a multi-variable and multi-criteria choice. It depends what you want to optimize. The warning you are talking about has nothing to do with these questions: after defining the 3D scene, PVsyst checks the compatibility between your specification of a number of modules (in the "System" part), and the area you have defined in the 3D scene. If you have defined a significantly too big area, or an insufficient area, PVsyst will warn you.

From version 6.60, the Degradation (year number for a simulation and degradation parameters) is indeed part of the parameters you can use/modify in the batchs.

The shading calculation is a geometrical calculation as function of the sun's position. The program doesn't calculate the optimal distance between strings, as there is no optimal distance. This is a multi-variable and multi-criteria choice. It depends what you want to optimize. The warning you are talking about has nothing to do with these questions: after defining the 3D scene, PVsyst checks the compatibility between your specification of a number of modules (in the "System" part), and the area you have defined in the 3D scene. If you have defined a significantly too big area, or an insufficient area, PVsyst will warn you.

Yes indeed, the irradiance on the PV module isw the GlobEff value. In the Help concerning the array temperature, this is a "simplification" just for explaining that this is the irradiance incident on the PV array, without referring to the details of the simulation (optical effects).

In PVsyst the cell's temperature is evaluated from the irradiance (and eventually the wind velocity) using a thermal balance, which is completely explained in the help "Project design > Array and system losses > Array Thermal losses". It involves namely a thermal loss factor U-value (expressed in W/m2K) which may be splitted into an constant Uc and a wind component Uv * wind velocity. The U-value should be adapted according to the installation conditions (free air circulation all around, or back insulated modules).

For a quick calculation, you can simply use "Unlimited Sheds" in the "orientation" part. Don't forget to define the electrical losses.