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Lazare Fesnien

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Everything posted by Lazare Fesnien

  1. Hi, You can account for the aging of the PV modules in ‘Detailed losses -> Aging’. This allows you to make a simulation for one specific year of operation. You can also make multi-year simulations in ‘Advanced simul. -> Aging tool’. PVsyst will not change the nominal power of the PV modules, but simulate with a model of degraded PV modules. This means that the performance ratio PR will decrease with time, since nominal power stays the same, but effective generated power will decrease. The aging of inverters is not modeled in PVsyst. For more explanations on how to use the aging tools of PVsyst, please see the corresponding help page : https://www.pvsyst.com/help/ageing_tool.htm
  2. Hi, It all depends on the characteristics of your system. There is no good or bad value
  3. Hi, This difference is due to several reasons : - In grid connected, the inverter has effective MPPT inputs to seek the maximum power point - Stand alone, regulators with MPPT don't have good efficiency. In the grid connected system, losses and gains are put by default in the tab "detailed losses" it's necessary to look at the two complete reports to visualize the differences.
  4. Hi, Can you send me an image of the error in order to understand the context ? Here are some explanations below while waiting for a complement : https://www.pvsyst.com/help/simulation_variables_standalone.htm?zoom_highlightsub=Array+oper https://www.pvsyst.com/help/simulation_process.htm
  5. Hi, The value 165.6 MWh corresponds to the energy injected into the grid (coming from your PV production). The value 158.9 MWh corresponds to the energy needed from the grid to supply your load profile. When your production is greater than you load profile, energy has to go somewhere, either into batteries or into the grid. If you want to use only the energy of your PV array, you must either modify your load profile or set up a battery park. Regards
  6. Hi, Currently, it's not possible to add consumer lines, we will develop this soon. Regards,
  7. Hi, These results are annual, to understand where the missing energy comes from you can look at the diagram of the losses month by month in order to control these values. Regards,
  8. Hi, Remember that the Active Power [kW] = Apparent power [kVA] * cos(Phi). The real power (i.e. corresponding to a useable energy) is indeed the active power. This is what is produced by the PV array and transformed by the inverter into output power. The apparent Power is the quadratic sum of the active power and the reactive power. But the reactive power IS NOT A POWER. You cannot produce movement or heat with it. If the limit is specified as Active power, the actual limit is completely independent on the Power factor.
  9. Hi, With an error in red, you cannot continue in the simulation. To resolve this error, you can uncheck the "efficiency defined for 3 voltages" box and click on the "efficiency curve" page to check if a EURO and MAX efficiency value is well defined.
  10. Hi, In case of doubts, you should use the default values of PVsyst: Rshunt and Rserie in order to get a low-light relative efficiency of -3%. You can play with these parameters. Please carefully read the Help " Physical models used > PV Module - Standard one-diode-model > Rseries and Rshunt determination procedure".
  11. Hi, This can be for several reasons : Total Self consumption (therefore grid injection equal to zero) Excessive overload etc... If necessary you can send us your complete project in ZIP format to support@pvsyst.com
  12. Hi, You can limit the power injected into the grid by indicating a limit from the "energy management" tab then "Grid power limitation". If this doesn't suit you, you can restrict the AC output power of your inverter by modifying the "Pnom" and "Pmax" values from the OND file. The production begins as soon as the MPP power is over the power threshold Pthresh of the inverter. The MPP power below this threshold is accounted as IL_Pmin loss. It is usually less that 0.1% over the year. PVsyst doesn't manage a Voltage threshold, as the Array voltage is not very dependent on the irradiance. Even with a very low irradiance, the array MPP voltage becomes significant. The Pthresh power may be understood as the power required for the Inverter internal circuits consumption. Some manufacturers claim for a very low threshold. We can observe that 0.5% of PNom would correspond to an irradiance of 5 W/m² (with respect to 1000 W/m²). Please remember that by very covered weather we have already 30 to 50 W/m² ! Please read our FAQ :https://www.pvsyst.com/help/inverter_inputmodel.htm?zoom_highlight=power+threshold
  13. Hi, You have an inverter with 10 MPPTs and in your case you tell PVsyst that you are using 11 of them. PVsyst doesn't yet allow you to wire two different characteristic subarrays to the same MPPT input.
  14. Hi, You can easily create hourly files with a large number of variables from "Advanced Simulation" then "Output File" Regards,
  15. Hi, Our languages of exchange are English and French. In order to answer you correctly, please send us your question in English or French. Regards
  16. Hi, In PVsyst there is no specific parameter for simulating floating PV installations. You might consider using a modified ambient temperature to account for the fact, that close to the water surface the temperature is generally lower during the day. So far I have not seen systematic studies on this, and there is no published model to account for this effect, so the best you can do, is to perform a direct measurement yourself. In PVsyst the relative humidity is only used to estimate precipitable water, in order to perform a spectral correction. This should be the humidity in the atmosphere above the PV installation and not the local humidity close to the PV modules. Therefore it should not change whether you have a floating system or a ground-mounted one. The albedo of water is generally lower than the one of land, so you might adapt this in the project parameters. PVsyst has no model to simulate the waving effects of water.
  17. Dear Fahad, It is possible to run several simulations at a time with varying parameters, and gather the results on a spreadsheet for easy parametric studies. Please read our FAQ : https://www.pvsyst.com/help/batch_mode.htm?zoom_highlightsub=batch+mode Tutorial video on our youtube channel :
  18. Dear YajMarc, In PVsyst, the Power factor may be specified by pressing the "Energy management" button, either as Cos(phi) or as Tan(phi). It may also be specified in monthly values. This will act on the inverter Pnom limitation if specified as Apparent power limit, and the apparent "energy" is mentioned on the loss diagram. Please read our FAQ : https://www.pvsyst.com/help/power_factor.htm?zoom_highlightsub=active+power
  19. Dear Sergio, Yes you can for that, you must click on "report options" available in the final report then click on "General options", you can change the language of the report from "Language" Regards,
  20. Hi, For the DC part: there is indeed a tool for a quick evaluation of the array's resistance in rather simple cases. This may involve combiner boxes. Please see "Detailed losses > Ohmic losses > Detailed computation". But if this is a complex layout, you can also calculate the wires resistance by yourself, see the help "Project design > Array and system losses > Array ohmic wiring loss". For the AC losses after the inverters, you have to define wire lengths and sections between inverter, transformers and injection points. You can do approximations if you have more complex circuits with combiner boxes. NB: we are preparing a tool for drawing the shema of the installation, which should be available soon.
  21. Hi, With stand-alone systems, PVsyst doesn't define an inverter yet. The user's needs are handled as an energy at the output of the system (DC). If you want to include an inverter, you should do that externally (in your EXCEL for example), by taking the efficiency into account. Sorry, with stand-alone systems, only one sub-array is possible. Therefore one only orientation. This is a limitation of PVsyst, that we should improve in the next months.
  22. Hi, Yes it's an improvement that we have in our improvement list. Thanks for your help
  23. Hi, It's already the case. In the box of the PVsyst report "AC wiring losses" it's indicated whether the AC loss is in relation to the STC or the Pnom.
  24. Hi, No, this option isn't yet implemented in the final report of PVsyst
  25. Hi, The power isn't identical (35 and 38 kW) this explains the difference Pnom/MPPT. To better help you we would need to analyze the complete project. You can send it to us at support@pvsyst.com
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