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Everything posted by André Mermoud
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There is now a way of defining the tariffs in hourly values on a CSV file.
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No, there are no PVsyst distributors in any country. The company PVsyst SA is the only distributor for the whole world.
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selfconsumption optimisation using water heating control
André Mermoud replied to Etienne Guerin's topic in How-to
Yes, you can define a "normal" system with self-consumption and storage, and consider the energy injected into the grid as the heating energy of the hotwater tank. The battery sizing is completely dependent on your requirements (load profile, PV power and required self-consumption). -
No, this result is not available in PVsyst. The only way is to perform 2 simulations, with systems equivalent to each sub-array.
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The simpler way is to redefine your inverter with 3 MPPT inputs, and attribute one sub-array to each input. The mismatch between orientations (i.e. between strings in different orientations) is usually very low (a fraction of %). You can check this by defining one sub-array with a "mixed" orientation. Here the calculation is correct, as it uses the mix of both I/V curves.
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Yes, if you define a "table" or an array of "tables", you have the opportunity of giving a slope to the baseline of your table. However this will change the orientation of your plane. See the FAQ "With sheds on a tilted roof, PVsyst changes my orientation"
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Yes, this means the proportion of data coming from Satellite data.
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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" ?
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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.
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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.
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pv loss due to irradian level at positive
André Mermoud replied to PAVAN91ROC's topic in Problems / Bugs
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 ? -
Non-zero inverter generation when GlobInc equals zero
André Mermoud replied to ebaughman's topic in Problems / Bugs
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.
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Multiple Year Single File Hourly Output Simulation
André Mermoud replied to joubert's topic in How-to
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. -
Using Measured Data for Bifacial Tracker projects
André Mermoud replied to BGiolitti's topic in Meteo data
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. -
One Diode Model Linear or Non-Linear Temperature Correction
André Mermoud replied to cq.trac's topic in PV Components
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
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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.
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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.
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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.
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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.
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Defining Imported Measured Irradiance Data
André Mermoud replied to kjs55's topic in Problems / Bugs
PVsyst doesn't take this difference into account in the present time. We are preparing the feature for a next version. -
Measured vs. Simulated Power Plot - Copy Values to Clipboard
André Mermoud replied to kjs55's topic in Problems / Bugs
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.