LauraH

I have the same question.

I'm not sure how I never noticed this before, but spectral correction is included in the loss inputs section of a PVsyst report even when the correction wasn't applied due to lack of any water vapor variable in the input met file. In this case, spectral correction is listed but there is no loss/gain listed in the waterfall diagram. I think this is VERY misleading and should be changed. Either take spectral correction out of the input loss list or put an error message where the data source is normally listed. The inconsistency makes it very difficult to figure out why no spectral gain/loss appears in the waterfall diagram when you know you turned on spectral correction. The issue is most likely to arise when modifying an existing project because the user may not check all the previous loss settings. All of the places where the spectral correction could be referenced in a PVsyst run that I can find are shown below for the case when spectral correction couldn't be run along with the input loss pane when RH is included in the met file.

Hi, Are we still not able to export SIT files in v. 8? I'm trying to upload a new met file for an existing project but can't pick the appropriate site because it's not in the list. I don't want to create a new site at the risk of changing the model. Any suggestions? Thanks, Laura

Hi, When I do a google search on "export PVsyst shade scene to PVC," the AI response is a long message that includes a description of this process, but when I click on the links the same search returns, this process isn't included. I also don't see an appropriate option under "Files" in the shading scene window. I would love to be able save my (updated) shading scenes as PVCs, but I now suspect that this is a case of AI hallucination. Is it, in fact, possible to do this export? If not, can I suggest adding this feature? Thanks.

Nevermind. I figured out the problem.

I'm trying to load a project I recently ran in v.7 into v.8. I follow the usual procedure: Click on "Import project," then select the project's zip file, as exported. A new window comes up that tells me to "Please choose a zip file containing projects." Why would I have a zip file containing projects inside a project zip file? Do I need to zip the zip file? This makes no sense and doesn't conform to the old procedure. Using 8.0.9. Thanks, Laura

I don't think that fully answers the question. Swonno is saying that projects that s/he already worked on in v. 8 don't show up in the list on v. 8. Why should this be? Thanks, Laura

I guess it depends on whether you think the degradation rate is a positive or negative number. When I see "annual guaranteed lower limit diminution rate," I think in terms of the magnitude. I believe that the warrantee specifies the maximum amount of degradation you are supposed to see, not the minimum. The minimum would be 0% (least degradation). The graph also shows that the warranted degradation rate is the greatest (largest decrease), but the resulting efficiency is the lowest. Personally, I would buy the modules with the lowest degradation rate. [Maybe this would be clearer if the words "greater" and "lower" were used rather than "higher" and "lower," because the second pair of words implies a direction rather than the overall size of a change? Not sure.]

Kanagavel -- The degradation used is the average over each year. The important thing is that the warranty is not an absolute value, it is a degradation RATE. So if the warrantee is 0.5% per year, the degradation proceeds as follows: Year 1: 0% to 0.5%, average 0.25% Year 2: 0.5% to 1.0%, average 0.75% Year 3: 1.0% to 0.5%, average 1.25% By the end of each year, degradation has increased 0.5%, so the step from year to year is 0.5% or the warranted rate. Note that, as stated elsewhere, this form of degradation isn't the only one the plant undergoes. For example, module capacity mismatch increases as some modules degrade faster than others. This is accounted for separately in PVsyst.

Could you confirm that the only inputs to the degradation calculations are the values circled in green here? I'm assuming that the red values are calculated and the warranty info is only for plotting. Thanks.

I found what appears to be a mistake in the latest documentation about the Aging Tool (https://www.pvsyst.com/help/project-design/array-and-system-losses/ageing-pv-modules-degradation/index.html?h=degradation#guaranteed-and-average-degradation-rate). Initially it says that the manufacturer's warranted degradation is the LOWER limit of degradation. This should be UPPER, as the first sentence of the next paragraph rightly states: "In these curves, the initial loss (of the order of 3%) should be considered as the LID, or initial Power possible deficit (tolerance, factory measurement uncertainty). Therefore the annual guaranteed lower limit diminution rate is the slope of this curve. In our example (-3% initial, -20% after 25 years), this means a rate of -0.68%/year. But this is not the degradation rate of the full array. In this tool we define an average degradation rate (for a set of modules). This loss value may be much lower than this guaranteed limit." [Incidentally, the help page is titled "Ageing" but the spelling "aging" is used in PVsyst. Apparently both are correct, but I don't think I've ever seen "ageing" in the US. It's extremely rare to have a silent "e" in the middle of a word.]

What resolution are the tested tracker angles, every 5 degrees? 2 degrees? .....

Thanks. I wonder how Google's AI came up with that. My interest isn't in improving production, it's in accurately modeling ATI trackers. They are tied together in groups of 2 to 20 rows (depending on model) controlled by a single motor. This layout is something that PVcase can represent, although I'm not sure how they determine the tracking angles.

If I search for "gang tracked trackers PVsyst" in Google, Google's generative AI (which I don't fully trust) provides a whole page of information about simulating these trackers in PVsyst, starting with "In PVsyst, "gang tracked trackers" refers to a type of solar tracker system where multiple trackers are mechanically linked together, moving as a single unit to follow the sun's path, essentially acting as a "gang" to optimize sun exposure on the solar panels; this design is often used to minimize mutual shading between trackers within a large array, maximizing energy production." and moving on to "How to model gang tracked trackers in PVsyst: Project setup: When creating a new project in PVsyst, specify the tracker type as "Horizontal axis" or "Tilted axis" depending on your design. Tracking settings: Within the tracker definition, select the "Gang tracking" option to activate the linked movement feature." However, I can't find any of this information on a PVsyst website/help page/etc. What's the story? It would be great if PVsyst could model these trackers, particularly with backtracking.

Hi, Normally, we model mixed module blocks by finding an equivalent block that uses just one module model. Could we accommodate a mixed block using the multiple MPPT feature? If the block only contains two module models that are identical except for bin class, say 445s and 450s, would that make a significant difference to the production on that inverter (due to differences in inverter operation, not just the module rating)? I'm wondering whether it's worth the effort to represent the block more specifically. Thanks!