dtarin

So this is the limitation in PVsyst in that we define tables smaller than our actual string size*. Before taking into account electrical effect percentages in PVsyst, the electrical effect loss is already underestimated when table sizes are smaller than the string size. A 70% electrical effect will not overestimate losses, it would be the opposite: 100% results in higher electrical effect losses compared to 70%. But since the partition size is less than the string size, that is a separate factor contributing to underestimation. This is more severely impacted with you have high undulations or tree shading. If you have significant undulations in your terrain, or significant tree shading, you will underestimate your electrical effect losses with a 70% setting in combination with a partition size less than your string size. This also depends on your stringing configuration & the type of module (half cell or full cell). So if you're conservative in your partition definition, perhaps you can go with something less than 100%. If you're aggressive in your partition definition, then you'll be underestimating electrical effect losses if you combine that with a lower electrical effect percentage. In your case, a table length of 20 will allow you to get closer to actual shading losses. Your 4x5 & 4x10 tables may need a different partition size to avoid underestimation if your shading is irregular and significant. *I've suggested to PVsyst they should allow for the option to exceed 100% electrical effect loss, because when we have smaller table definitions (relative to string size), we have little to no means of compensating for the underestimation of losses even when setting to 100% electrical effect. That is until the module layout method is actually useable for larger systems, or something else is implemented.

US-based designs are in ft, yet the pitch input is in meters and only to two significant figures, resulting in (backtracking-related) issues when converting. Please increase to four decimal places.

There is no straightforward answer. Are you modeling tracker or fixed tilt? What is your table size in PVsyst shade scene relative to your string length?

Your PAN and OND files are not correct.

I've been getting this often, and PAN/OND files being invalidated

There should be a report which accompanies the PAN file that details the IAM calculation. If there is not, I personally wouldn't use it until there is such a report available.

For shading calculations by considering very long rows, unlimited sheds ignores edge effects. Modules on the edges of an array will have lower shading losses compared to modules on the interior of an array, which is what unlimited sheds captures. This has a tendency to produce less accurate shading losses compared to generating a 3D shade scene.

Temperature yes, if it is specified in the OND file. Voltage, I am not sure.

See here. https://forum.pvsyst.com/viewtopic.php?f=23&t=5316

You are not required to choose one of the pre-sizing features. Simply select No sizing.

If you are using PVcase, you can export that shade scene very easily into PVsyst.

What PVsyst does is it calculates the rear-side irradiance contribution, adds this irradiance gain to the front side irradiance, and then computes the generation using the combined irradiance. The current and energy values reported by PVsyst will consider this total irradiance (rear side + front side). If you would like to find out how the rear irradiance affects current, you can try this: Run a bifacial simulation, output in the 8760 current Run a monofacial simulation for the same variant (just disable bifacial under system, use the same module); output current Compare the current output for each run Voltage seems to also be slightly affected.

Hello, It would be helpful if the Check scene validity tool was revamped. Something like a side menu opening up with a list of all items discovered, where the user can select the table/object would be great.

Another option is meteonorm. The methodologies are similar. They use a digital elevation model and trace back out from the point of interest, calculating the height of the terrain for various azimuths. I think outside of on-site measurement, both are reliable. I have not seen a validation study, however.

-10C is the default minimum site temperature defined in project settings. This needs to be set per your specific location. If -10C is your site minimum temperature, then you need to adjust your string length so your Voc voltage does not exceed the voltage rating of your inverter.

You can have them both in the same project by defining two subarrays under system, or you can model them separately in 2 different variants.

If you mean power factor, yes, under energy management

yes. Use the mppt share function of the inverter. There are many threads on this.

See thread here. https://forum.pvsyst.com/viewtopic.php?f=23&t=5316 Your load profile should be based off the template included in PVsyst.

Run two models, one with monofacial, one with monofacial set with bifaciality set to zero and compare.

Yes, it is correct that a 3D shade scene is more representative. The edge refers to the the modules which are along the edges of the array. If you have a square block, it is the first row, top row, left side, and right side. These modules receive less shading, more reflected irradiance, etc, and hence more energy.

Check your PAN file. Your Vmp value does not seem correct, it is too high. For a 1500V system, you should be in the mid to high 20's for string length. You also want a higher DC/AC ratio, 1.2 to 1.3 good range. I suggest getting a new PAN file, or double checking the IV characteristics against the datasheet.

Find this template, and populate it with your data. The template is located here: C:\Program Files\PVsyst7.1\DataRO\PVsyst7.0_Data\Templates (or whichever version you are using). The template filename is PARAMS_Hourly_Parameter_Template.csv. This is what it looks like after loading the template file.

Once you're ready to simulate, click advanced simul. menu, select output file, check filename so that a 8760 file will be generated, press ok. click batch simulation, check the box create hourly files, and create pdf report; verify your variable under test, and the output variables under results variables specification, press okay. run simulation. 8760 files will be in /UserHourly, PDF files will be in /UserData, BatchParams and BatchResults will be in /UserBatch

When importing a custom weather file, create a new conversion format based on your data file. There is a place to update the time shift. You will need to import the meteo file first each time to see the time shift, and then go back and adjust in the conversion format as shown. If you want to upload the excel file for your data as a template, I can create a conversion format file for you. Just fill in all of the data with 1's, leave the headers, date, and other formatting as is.