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kjs55

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  1. 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.
  2. 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).
  3. 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.
  4. 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.
  5. 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. unshaded Keywords (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
  6. 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.
  7. 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.
  8. 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).
  9. 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.
  10. 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.
  11. 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.
  12. Following up on this. ~1-min. is not enough time to make important edits to our PVsyst Forum posts. Thanks.
  13. 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)? [1] https://www.researchgate.net/publication/318259323_A_Framework_to_Calculate_Uncertainties_for_Lifetime_Energy_Yield_Predictions_of_PV_Systems/ [2] https://www.eupvsec-proceedings.com/proceedings?paper=19917/ [3] https://onlinelibrary.wiley.com/doi/10.1002/pip.3566/
  14. 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!
  15. 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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