dtarin

I would recommend also collecting ambient temperature (Tamb) and plane of array irradiance (POA) at a minimum. With POA, Tamb, windspeed, and power output, you can conduct a capacity test according to ASTM E2848 to compare the model and measured data. Since you are considering bifacial, you might also want to include backside irradiance and albedo.

Yes, the hourly output file. The variable to select is inverter output (EOutInv). It will be the sum of all inverters. Check the maximum hourly output against the (number of inverters * inverter rating).

Interesting find.

The PV engineer should determine the number of inverters to use in PVsyst and enter that number, taking into account elevation, ambient temperature, etc. PVsyst will display Pnom on the report, however if you check the 8760, it will reach 215 max output (assuming you have the irradiance and enough DC), not 200. Inverters are not sized by the average temperature of a location, though. Usually a higher temperature is selected so that nameplate is guaranteed for most operating conditions (http://ashrae-meteo.info/v2.0/). Note that the inverter manufacturer has defined Pnom here, not PVsyst. Nevertheless, your output is not being limited to Pnom.

Yes, the PAN file is associated with PV modules, and the OND file is associated with inverters.

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.