Rapha123

Hi, When I run a simulation which has horizon shading effects and also output the hourly file, there is a difference in the monthly HrzLoss values when you export a customised table compared to the sum of the hourly values which have been exported on an output file. I've tried this on a few projects and got the same results, with the monthly values greater than the sum of the hourly values. The hourly values are given in W/m2 but summing them should be equivalent to the monthly value given in kWh/m2. Is this a bug or am I doing my calculations wrong? Thanks, Rapha

I'm trying to process an 11MW PV plant through the module layout tool however when I try to match all tables it states a "Floating point overflow". Is this because the system is tool large for PVsyst to handle and I should reduce it?

Hi, Since udpating PVsyst for v6.13 I get an error whenever I try to implement a shading model. Basically when I finish building the model and close the scene I get this error: "Access violation at address 00ABB308 in module 'Pvsyst6.exe'. Read of address 00000000. Please resolve asap as I cannot do any yields! Thanks R

Hi, I'm modelling a PV plant on a field which slopes towards the west. I have built the 3D shading model based on the topography of the land varying the baseline slope. It also slopes southwards so I have adjusted the shed-shed slope. This gives a "real plane orientation in the global scene" different to the defined specifications. This then edits the system orientation and complicates the rest of the model. Is there anyway for modelling it based on the "defined plane orientation" rather than the "real plane orientation" whilst incorporating the topographical effects? Thanks, Raph

Hi, An increasing number of manufacturers are providing test results for the IAM profile which give significantly improved losses compared to the default settings in PVsyst (at least 1% lower losses). It is possible to input these values into PVsyst, however if the results aren't provided, is it a reasonable assumption to assume a b0 factor of 0.04 for all ARC glass modules? Cheers, Raph

Hi, Since updating the 6.08 the PR given in the report is wrong compared to the output loss factors. Calculate the PR using these values and it is 0.7% under in my case. Thanks, Raph

I have a module with very low "low irradiance" losses for a site in the UK when using the .pan file from PVsyst which has been provided by the module manufacturer. I also have additional information on the Rseries and Rshunt values as well as efficiency values from the manufacturer at different irradiance levels. However the shunt resistance profile appears almost linear rather than exponential. Is it safe to consider inputting the measured values for Rseries and Rshunt or just rely on inputting the low irradiance efficiency profile to accurately predict the output of the module? Thanks, Raph

I have been thinking and I don't think horizon shading should be included in the PR calculation, it should be subtracted from the global inclined irradiation then the PR is calculated from this effective GII. This is because if you have a pyranometer installed on-site in the plane of the modules, you will never get theincident irradiation which has been blocked by the horizon shading. Thoughts?

When I try to import a file from Meteonorm and attempt to edit the internal file name to be created, it doesn't allow me to name the file, instead it just reverts to my name. Cheers, Raph

Hi, Using PVsyst 6, when producing the table of results, IAM and Near Shading losses are equal to zero, even though there are losses. (see attached filed). Thanks, Rapha

You can specify this using the electrical effect of the mutual shadings in the orientation tab, putting in the dimensions of the strings. Also when you partition modules in the 3D shading diagram you can specify the orientation of the modules.

With more accurate sources of solar irradiation data with higher temporal resolution, PVsyst would be considered more accurate if 15 minute temporal resolution modelling was possible. There are several papers out there such as by Sandia explaning the much greater accuracy of using 15 minute resolution data compared to hourly data. I assume this would not be too much of an ask and as computers are more powerful nowadays, the time for simulation should not be too much of an issue. Thanks, Rapha

When you generate Tables after running a simulation you can see what the headings correlate to. POAI is Ginc.(Inclined irradiation).

There are two ways, you can change the minimum temperature in Project -> Site and Meteo -> "Lower temperature for VmaxAbs limit. Chaging from -10C to a say -5C will then work. The actual minimum temperature depends on the site location.

When you go into the near shadings tab it should give you a warning that you can't define near shadings with a seasonable adjustable array. My suggestion would be to run two simulations, one at each tilt angle. Then take a yearly average using the monthly values corresponding to each tilt angle.