Linda Thoren

Hello, Indeed the PVsyst simulation is hourly based, so any sub-hourly phenomenon has to be averaged. This includes the weather data or self-consumption. The main reason for this limitation is that we currently consider that Perez’s transposition model is not well calibrated for sub-hourly data (EUPVSEC 2023). Sub-hourly simulation should be available in PVSyst 8.1, but the release date is not yet defined (it will be after 2025). Nonetheless, we included a sub-hourly clipping correction in PVsyst 8.0, allowing the simulation to consider sub-hourly irradiance fluctuation for clipping (EUPVSEC 2024) You can refer to the dedicated section in our help page for more information. The last option is to use the so-called pseudo-subhourly simulation. The idea is to run n hourly simulations (in your case n = 60min/15min -> 4 ) then recombine the results. You can find a PDF tutorial about the whole process in our website: pseudo sub-hourly simulation This process can even be automated if you have a PVsyst CLI licence. You can find an application of pseudo-subhourly simulation using PVsyst CLI in python in the help Please note that pseudo sub-hourly simulation cannot be used with energy storage systems. Best regards,

Hello, The available area in the Pre-sizing help in the System window, serves as a guide for a first order of magnitude of how many panels you can fit on a dedicated surface. This tool take only the size of the panels into consideration (not the spacing between the panels or a pitch). If no 3D scene is defined, no configuration other than what is defined in the system and orientation window is considered (no shadings). Defining a 3D scene with the surrounding shading elements, include electrical shading definition etc. will more accurately simulate the system. You find a tutorial for the 3D tool in the following link: Another potential important parameter for a vertical system would be the reflection on the ground. For a monofacial system, this is discussed in the following forum page:

Hi, Indeed the maximum number of rectangles is limited to 100. However, in most cases—even for large-scale projects—each table typically contains only a few strings, so this limitation normally is not issue. For example, if each table includes four twin half-cell panels arranged in portrait orientation, and each row of panels in the table corresponds to a single string, then the table would require eight rectangles in width (x-direction). Could you please clarify how the system layout is defined in your example? You can find more details about the partition model in the following help page https://www.pvsyst.com/help/project-design/shadings/electrical-shadings-module-strings/index.html?h=partition

Hello, If all the strings have the same length you can indeed use the Power sharing within the inverter. The two options should give the same result.

Hi, Changing these values in the project settings will not affect the simulation results — it will only have an impact in the triggering of the error message. The error message is designed to protect the inverter from potential damage when the absolute maximum input voltage is exceeded. In this situation, there is a real risk of damaging the inverter.

Hello, You set the Lower temperature for Absolut Voltage limit in the Project Settings, Design conditions window. Kind regards

The P50-P90 is fully described in the following youtube tutorial:

Hello, In the following youtube tutorial you find how to define the thermal parameters, soiling losses etc. Kind regards,

Hello, Indeed, since successive losses will affect the active power, the power factor at the injection point may differ slightly from what you entered in PVsyst. Kind regards

All the most important losses are illustrated in the loss diagram that is generated after running the simulation. Here you can clearly see what kind of losses your project suffer from. The P90 will depend on the variability and uncertainties you define in the Energy management window.

The structure shading factor is design to reflect the area covered by the structures. The electrical effect of this shading should be reflected in the mismatch loss factor. Thus if I understand your example correctly, the mismatch loss factor should be set to 40% if 40% of a cell in the concerned sting is shaded. For the structure shading factor, define only the ratio of the area covered by structures to the photovoltaic area.

it is the coefficient set for that specific PV module technology. You can find additional information in the following help: https://www.pvsyst.com/help/physical-models-used/pv-module-standard-one-diode-model/firstsolar-spectral-correction.html#spectral-correction-in-pvsyst

Hello, In the loss diagram, each loss is defined as percentage of the previous energy quantity. In general, if you have defined a continuous auxiliary loss and export an hourly output file, you will see that this value will remain constant, though the percentage it will represent will of course vary depending on the production (if you for instance look at the loss diagram for the different months). You can read more about the loss diagram and the auxiliary losses in the following help page: https://www.pvsyst.com/help/project-design/results/loss-diagram.html https://www.pvsyst.com/help/project-design/array-and-system-losses/auxiliaries-consumption.html Please let me know if this answers your question. Kind regards,

Hello, When defining monthly values, it is assumed that the consumption that month is identical throughout the month. Thus from kWh/month to an average power is simply a calculation of how many hours there are per month. Note that the average power need for monthly values are reflecting day and night consumption, thus it does not directly make a very good basis for the needed installed AC capacity, but at least a fist order of magnitude.

Dear Shivya and Ben, This is difficult question and we do not have a direct answer. As a first approximation, the structure shading could be estimated as the ratio of the area covered by structures to the photovoltaic area. In this approximation, the effect of structures is therefore their projection on the rear plane. Therefore, it neglects the fact that light may arrive on the rear side from multiple directions, akin to diffuse light. This approximation is hence likely an underestimate of the shading loss, in full generality. Indeed, even if structural elements are not directly in front of the rear side of modules, they may cause significant shading. A better approximation is beyond the present possibilities of PVsyst. Then there is the the variable for the mismatch loss factor, caused by a heterogenous irradiance distribution on the rear side. Any source of heterogeneous irradiance will cause electrical mismatch effects. Such is the case of shading cast by structural elements (but also differences in location relative to the environment and the ground). At present, PVsyst has no easy way to make an accurate estimation for these effects. Based on comparisons with measurement data, we have determined a default value (10%) for a general case. With beams covering the module width directly in front of the rear side of modules, the mismatch losses may increase drastically. In such a case, one can roughly estimate the mismatch effect as follows: as the current in a string is the current in the worst cell, if the structure covers x% of one cell, the shading effect will be x% for the concerned string. For example, the loss may be reduced by a factor of 2 if the structure covers half a cell (or two half cells).