André Mermoud

Yes, this means the proportion of data coming from Satellite data.

The "Module quality loss+ is a parameter at your disposal, for any purpose. Only the default value proposed by PVsyst is based on the PV module tolerance specification. Please see the FAQ How to define the "Module quality loss" ?

This is really strange as this file should not be located here, in any way... This is the second case of this problem. I don't know how this could arise. Please delete the PVsyst.INI file, this should solve the problem.

This is really strange as this file should not be located here, in any way... I don't know how this could arise. Please delete the PVsyst.INI file, this should solve the problem.

A gain due to the low-light efficiency is possible, especially in very sunny places. However this usually indicates that the PAN file has been specified with a very high series resistance, resulting in high low-light performance. See the FAQ How are specified the PAN files in the PVsyst database ?

I really don't see how this could arise. Please send us an example, at support@pvsyst.com

What you need is indeed provided by the "Grid system", using the "Grid storage" option, "Peak shaving". However this option doesn't define a DC converter in parallel with the Inverter yet. The Inverter is supposed to deliver the extra-power for the battery, so that it should be sized for accepting the peak power during the best days. We will develop this feature in a next version. In the mean time, the results with an oversized inverter sould be quite equivalent to a separate DC converter.

You can define different conditions from simulation to simulation using the Batch mode. Each simulation may produce an Hourly CSV file. But these resulting hourly CSV files will be independent. If you want to gather them in one only file you have to do that manually.

You can indeed import the POA measured on your trackers. But be careful: this measurement is subject to the same mutual shadings on the diffuse part than the value calculated by the simulation (linear shading loss on the loss diagram). So this measurement is not really suited for a good simulation. The best way is to use the measured Global horizontal. If you have also the diffuse at disposal, this is indeed the top for the accuracy of the transposition models. Now the Rear side irradiance measurement is extremely delicate, as the reflected irradiance is not homogeneous behind the tracker. In the present time this measurement is not useable as input for the simulation. The relationship between this value and the GlobBack calculated by PVsyst is not well established.

This is an artefact of the one-diode model. For numeric reasons, I had to limit the Diode Saturation current at a threshold value of 0.01 pA. When limiting to this value, the muPmpp becomes positive. This arises at very low temperatures, when you define a Rseries value close to its maximum RSMax. I judged that below -10°C, this remains acceptable. By the way even if the muPmpp becomes positive the one-diode model still works correctly. Simply the Pmpp doesn't increase anymore when going towards lower temperatures.

TArray and TArrWtd are based on the same TArray hourly data. Only the way of averaging these data is different: - TArray is a simple average of all values when the system is working. - TArrWtd is an average weighted by the irradiance: TArrWtd = Sumh (TArray * GlobInc) / Sumh (GlobInc) where Sumh = sum on hours

This is indeed an erroneous situation within the original Meteo data. PVsyst should normally check this at the import time. But the import of each provider is different, and perhaps this has not been checkd during your import. Moreover these checks have significantly evolved since this old version 6.43. NB: If you want to use these data, you have to correct them in the original meteo data file, before importing them.

The PID is not taken into account in PVsyst. We don't know any model describing this loss, which varies along the system life according to operating conditions (and module's quality !). If you want to take it into account for a particular year, and you know its amplitude, you have to specify it either as a LID loss, or with the "Module Quality Loss" parameter.

For defining arrays of trackers, you should use "Create > Tracking PV planes" in the main menu of the 3D editor. It is not yet possible to distribute trackers in a zone. If you define tables (sheds) in a zone, you can modify the tilt angles globally by selectring the desired tables, and use "Edit > Modify selected objects" in the main menu.

I don't see how you have evaluated these loss percentages. By the way the mismatch losses are not cumulative, as each of them implies a displacement of the Pmpp on the I/V curve. You have a detailed tool for studying the mismatch between strings: In the system dialog, "Detailed Losses > Module quality-LID-Mismatch", you can press "detailed study". Here you can press F1 for a description of the Mismatch problematics. Usually the mismatch between strings (in voltage) is extremely low.

PVsyst doesn't take this difference into account in the present time. We are preparing the feature for a next version.

It is noted in the Help that the copy of Graph's values to the clipboard is not always reliable. It depends on how the graph has been internally constructed. You should consider this as a facultative bonus, and be happy when it is available...

When there is a bug in a version, we cannot modify this version in any way. If there is no workaround, you can: - either upgrade to a more recent version, - or revert to a preceding one. You can always download and install older versions from our site www.pvsyst.com, and install them in parallel with your working version. Both versions use the same license.

The LID loss is obviously not recovered after some few hours. If you have a module of, say, 300 W, and a LID loss of 2%, the module will deliver 294W after some few hours. But there is no reason that is gives 300 W again at the end of the year! The LID loss is a permanent loss, for the whole life of the module.

This is not a bug. During the simulation, the GlobInc threshold is used as an indicator for the night time. Setting it to 0 is incorrect.

The development of the SolarEdge systems has been done in close relationship with SolarEdge. SolarEdge edicted very complex rules for each of their components and associations of components. PVsyst strictly applies the requirement of these SolarEdge rules. Please ask SolarEdge people for the reasons of these constraints.

The "Miscellaneous tools" button has simply been renamed as "Energy management", which seems more appropriate in this case. The features inside the button are unchanged.

The right way is to sum all the values of the numerator, and all the values of the denominator. I.e. divide the sum of all E_Grid by the sum of all (GlobInc * PnomPV) products.

No, this is not possible. By the way I don't see well which kind of usual application would have energy needs just corresponding to the PV production at any time. The only practical case I know is the pumping, where the pump's power may be modulated according to the sun's availability at any time. PVsyst treats such pumping systems. We could also think about some air-conditionoîng units, but I really don't know any suited device for that.

For the interpretation and difference between the project's albedo and the Bi-facial albedo, please see our FAQ "What is the effect of changing the albedo in the project ?". Now the mention of albedo in the Horizon part is not another definition of the albedo. This is an interpretation - and correction - of the project's albedo in shading situation. If you have an obstacle (far shadings) rather close to your system, the albedo of the terrain in front of this obstacle may be diminished due to the fact that the irradiance is lower for this area (ie the terrain is in the "shade" of the sun), and this area is not so extended as an "unlimited" terrain. For details, please see the Help "Project design > Shadings > Far shadings - Horizon", especially the paragraph "Treatment during the simulation process".