kjs55
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Posts posted by kjs55
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Edit: Even simpler option, b/c there's already a section on "3D shadings parameter":
Existing language:
"""Plane orientation
- Modify tilt, azimuth, or shed characteristics (pitch, electrical effect) if unlimited sheds defined."""[1] https://www.pvsyst.com/help/batch_mode.htm
New proposed edit:
"""Plane orientation
- Modify tilt and azimuth for fixed tilt orientation (presently limited to a single orientation) plus shed characteristics (pitch, electrical effect) if unlimited sheds defined.""" -
Hello, I saw this post at the same time as the other. In the PVsyst help documentation for batch mode [1], it presently says:
"""Plane orientation
- Modify tilt, azimuth, or shed characteristics (pitch, electrical effect) if unlimited sheds defined."""[1] https://www.pvsyst.com/help/batch_mode.htm
Of course, I defer to the @PVsyst team, but I propose this edit:
"""Plane orientation
- Modify tilt and azimuth for fixed tilt orientation (presently limited to a single orientation) plus shed characteristics (pitch, electrical effect) for unlimited sheds and certain other characteristics (Nb. of trackers, backtracking, phi limits) for tracking PV arrays.""" -
Hello, I happened to see this post and discussed it with a colleague and we have a few initial Qs:
1. What's the GCR in both cases (fixed tilt and tracking)?
2. What's the tilt angle of the fixed tilt PV system?
3. What's the tracker rotation limit (for the tracking PV system)?
Thanks.
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Is it on PVsyst's product development roadmap to enable users to run custom 8760s of tracker (phi) angles? I see this as becoming increasingly important given the increasing prevalence of custom tracking/backtracking algorithms, hail + wind stow strategies, etc. Other, PVsyst-competitor PV simulation software programs (e.g., DNV's SolarFarmer) are reportedly already offering this modeling feature in their energy production simulations. Thanks.
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I just set a Grid power limitation such that the Hidden Parameter "High Grid Power limitation Power Ratio" set point value is exceeded. I was able to run a simulation with no errors/warnings/error messages/warning messages.
I did not test whether the Hidden Parameter "Low Grid Power limitation Power Ratio" is also ignored.
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I can't figure out how to apply a grid power limitation of <1 kW.
I tried changing the Hidden Parameter "Low Grid Power limitation Power Ratio", and it didn't work.
Also note that the the simulation says "Ready for simulation" in green, but the option to "Run Simulation" is not available (grayed out).
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Suggestion is to add one decimal place (significant figure aka significant digit) to the azimuth and tilt in the PVsyst output report PDF (instead of rounding to the nearest integer) to match the inputted azimuth and tilt model parameters in the PVsyst model.
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Please add a "Clear Formatting" option to the PVsyst Forum.
e.g., When you paste content into a new forum post and then add a carriage return somewhere within the text, it results in extra line spacing. It'd be helpful if we could then highlight the entire text and click "Clear Formatting", so we can resolve this formatting issue.
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A useful starting point would be a clear specification of the measured GPI (see my comprehensive list of real-world options above). Namely, please instruct us clearly on how to properly measure GPI data for application/import into PVsyst.
I thought at one point I'd seen it written that the measured GPI data must be entirely unshaded (within geometrical/physical limits), but I just looked through the PVsyst Help Menu, and I can no longer (easily) find this instruction (so perhaps it never existed).
Considerations:
- Monofacial (front-side irradiance only) vs. bifacial (rear-side irradiance also)
- Pyranometer (dome-shaped) vs. reference cell (flat-glass)
- Shaded vs. unshadedKeywords (search terms):
ASCII text file
Back-side irradiance
Bifacial
Custom file import tool
Dome-shaped
Front-side irradiance
Global Plane-of-array POA Irradiance GPI
Global Tilted Irradiance GTI
Incidence Angle Modifier IAM
Measured data
Measured GPI
Meteorological meteo weather data
Monofacial
PVsyst
Pyranometer
Rear-side irradiance
Reference cell
Shadings
Sunny-side down
Sunny-side up
Unshaded -
I think it would be a useful feature to allow the custom import and direct use (simulation) of measured weather data (without hourly averaging). I think it would be relatively straightforward to write a PVsyst wrapper where the data is preprocessed into several 8760s on the front end, run through the core PVsyst tool as normal, and then post-processed on the back end. Namely, 1-min. measurement data is split into (60) 8760 files, 5-min. data is split into (12) 8760 files, etc. on the front end. Then, normal PVsyst is run over a loop (60x or 12x, respectively), with the appropriate time shift for each run. Then, the resultant output files are recombined on the back end (back into a 1-min. or 5-min. data set, respectively). In other words, there are really no major changes to the core PVsyst tool needed in order to implement this feature to enable simulations of (at least) custom, imported subhourly measurement data. Thanks.
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Help Menu Navigation: Project design > Shadings > Calculation and Model > Treatment of the Diffuse component > Global calculations on diffuse
Emphasis mine (bold italics):
"""Therefore for each direction, we should evaluate the product of the Far shadings, Near shadings and IAM loss as parameter for the integral. Along with the last irradiance loss (soiling, independent on the direction), this leads to a constant global loss factor for diffuse, used for the calculation of the "Effective diffuse" component in the simulation."""
The use of the word "should" here leaves me w/ the question: Would you please confirm that Near Shadings are included in diffuse irradiance shadings? Even for unlimited sheds, i.e., not only for 3D scene modeling? Many thanks.
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Would like the option to time shift imported data by, e.g., 2.5-min. (or 7.5-min., etc.). Presently, it appears PVsyst only allows imported data time shifts in integer intervals (increments).
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Sorry, I must have made a typo. I meant to say that I'd like the option to set Energy units to Watt-hours Wh in this GUI Window #1:
1. PVsyst > Settings > Preferences > Default values
Presently, you do have the option to output data in Watts (Watt-hours), not just kW (kWh), in this GUI Window #2:
2. Grid-connected > Advanced Simul. > Output File > Units
As I said above in this thread, in general, I'd like the settings of GUI Window #2 to draw from the user-defined settings of GUI Window #1.
If you don't want to use W (Wh), then I suggest to remove the option altogether from the PVsyst software program (i.e., from GUI Window #2).
Finally, I'm not sure why the unit in GUI Window #2 says "Power" while the unit in GUI Window #1 says "Energy" (I think this confusion led me to make my previous typo).
Hope that makes more sense. Thanks again.
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Suggest to allow modeling multiple sub-arrays w/ the same orientation. Presently, you get the error "The orientation X is redundant. Do you want to delete it?"
Would eventually like to assign albedos (#1) and shading scenes (#2) to different sub-arrays, even if those sub-arrays have the same orientation. I've already added posts to the PVsyst Forum requesting these two (#1 & #2) features.
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Would like the option to model multiple albedos for a given project (rather than the existing, project's global implementation). Not sure how to best implement this; perhaps associated w/ each sub-array. I'll follow up if I think of any other ideas. Thanks.
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Following up on this. ~1-min. is not enough time to make important edits to our PVsyst Forum posts. Thanks.
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It is reported in literature [1] that the p50 (median) derived from a Monte Carlo- or convolution-based uncertainty analysis [2] is more appropriate to use (and not always the same) as the primary AC energy into grid value (E_Grid simul) that comes out of PVsyst. e.g., Not all the distributions that feed into the Monte Carlo are normal Gaussian distributions (e.g., the Gamma-shaped degradation rate distribution from Dirk Jordan [2]-[3]). Does the p50 in the PVsyst p50 estimation directly use E_Grid simul? Or is the p50 derived from the uncertainty analysis? Is it really a median p50 (or is it simply E_Grid simul)?
[2] https://www.eupvsec-proceedings.com/proceedings?paper=19917/
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PVsyst > Settings > Preferences > Default values
Would like the option to set Energy units to Watts & Power units to Watts here in this window
Would also like to be able to specify the default date format here in this same Preferences GUI window (e.g., DD/MM/YY vs. MM/DD/YY) -> Same set of date options as in the "Definitions for ASCII output file" GUI window
Basically, it'd be nice if we could define our preferred options for the ASCII output file under this Settings\Preferences window. Then the ASCII definitions window references (obtains settings from) these selections in the Preferences window. Hope this makes sense. Thanks!
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FYI only, the geographical site definition GUI (PVsyst > Databases > Geographical sites > New > Geographical Coordinates > Country) has BOTH USA and United States.
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FYI only, I noticed that some of the PVsyst input data folders are missing from the main file directory Help Menu page:
https://www.pvsyst.com/help/file_workspace.htm
Namely,
- ComposePV\Clients (is NOT presently documented elsewhere in Help)
- UserBatch (IS documented elsewhere in Help)
- UserHourly (IS documented elsewhere in Help)
- UserHourlyParams (IS documented elsewhere in Help)
- UserImages (is NOT presently documented anywhere in Help)
- UserOptimization (is NOT presently documented anywhere in Help)
- UserRecycleBin (IS documented elsewhere in Help)
Recently, I had to import *.GIM & *.JPG files, & I wasn't sure where to put them. I checked the Help Menu & couldn't find any associated documentation (in this case, of the UserImages folder).
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I agree w/ @johank that it would help to have the .SIT file included in the exported project .zip. If the .SIT is modified w/in the project, then perhaps that can take a different filename extension (.SIF, .SITm, .SITx, etc.).
e.g., When I want to import Measured Data for a given project (a posteriori), I want to use the same .SIT file as used in the pro forma (a priori) PVsyst simulation. Having to manually recreate this .SIT file (b/c it does not appear in the database) introduces the possibility of user error.
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Thanks. In my original post, I used the PVsyst default, semicolon separator. Indeed, when I switch to the comma separator, it opens properly in Excel. I'm still a little surprised that, when using semicolon, only one single row (Row 6) has data which spills out of Column A into columns B, C, etc. when you open the file in Excel. Namely, I'm surprised the design of Row 6 is this:
Existing semicolon design (Row 6):
Simulation variant;US-Project_name_carport2_rev07.VCF;13/05/22 14h49;tilt3, pitch50,YL530, unlimited sheds, 1340, bifacial albedo 0.1, rev07;
Instead of this (proposed semicolon new design) (Row 6):
Simulation variant;US-Project_name_carport2_rev07.VCF;13/05/22 14h49;tilt3;pitch50;YL530;unlimited sheds;1340;bifacial albedo 0.1;rev07;
(Note that all I did was replace some of the commas with semicolons & eliminate some spaces.)
In the proposed semicolon new design, everything works well. In the existing semicolon design, you get a warning in Excel and data gets overwritten when separating the columns by semicolon.
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Steps to reproduce:
1. Export output 8760 .csv file via PVsyst simulation
2. Open in Excel
3. Click "Text to Columns" > Delimited > Semicolon > Finish
WARNING MESSAGE: "There's already data here. Do you want to replace it?"
This is b/c there is data in Column B. There should only be (delimiter-separated) data in Column A. Please fix this formatting issue in the output 8760 .csv file. Thanks!
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@dtarin: Thanks for weighing in on that one point. Here's a reference I found to support your first claim: https://www.pvsyst.com/help/iam_loss.htm
Missing from Uncertainty Analysis: Weather Data Uncertainty?
in Suggestions
Posted · Edited by kjs55
Remove commas
The weather (solar resource) data uncertainty contribution (e.g., solar irradiance measurement uncertainty) appears to be missing from the uncertainty propagation in PVsyst (?), thus leading to significantly overly aggressive P99s. Please consider incorporating this #1 source of uncertainty into the uncertainty analysis in PVsyst. Thanks.