Muthuraj

Hi Yoline, I guess you have used bifacial module. PVsyst does not take 'rear side irradiation' into account in the calculation of PR. That's the reason for such high value of PR. Hope it clarifies your doubt.

I am using PVsyst 7.2.4. Although batch simulation is being executed as defined in the Parameters file, the Results file is empty. Anyone faced similar issues? Kindly help if there is a solution. Thanks.

Hi, In PVsyst 7 hourly output file, sum of beam, circumsolar, diffuse and albedo incident in collector plane does not match with GlobInc (Global incident in collector plane). Then, I found CircInc values are NIL. Morover, ShdCLss (Near shadings circumsolar loss) are non-zero. I guess the newly introduced CircInc is not getting updated in the hourly file! Kindly clarify. Thanks.

As I understand, PVsyst 6.86 uses only front side irradiation for calculating PR. This is evident when rear side irradiation is significant which results in >100% PR. Try running bifacial simulation with E-W configuration. Hope it helps.

Hi, I am currently using PVsyst 6.86 where I tried to compare meteo data from Meteonorm 7.2 and NASA-SSE for a high altitude site. Although GHI values roughly match, significant difference (13 to 20 deg C) is observed in monthly values of temperature which leads to following questions. (1) NASA-SSE database contains different temperature values like earth skin temperature, air temperature at 10m (min, max, avg), etc. Which one is used in PVsyst 6.86? (2) Similarly, Meteonorm also contains different temperature values like surface temperature, air temperature at 2m, etc. Which one is used in PVsyst 6.86? (3) Although NASA-SSE dataset's spatial resolution is large (1 lat x 1 long), for most of the low altitude sites that I have seen, temperature values match roughly. Is this a problem only in high altitude regions? Any specific reasons. Thanks.

For optimum fixed tilt angle & pitch, I generally use "Unlimited sheds" in "Orientation" section. I manually vary "pitch" and get "Transposition Factor" vs "Tilt angle" graph. From the graph, I get the optimum tilt angle corresponding to the given pitch and the respective "TF" value. So, I get a table of pitch, corresponding optimum tilt angle & TF. However, for seasonal tilt, I could not use this way as "Unlimited sheds" does not allow multiple tilt angles. Is there any other way to calculate optimum tilt angles for various pitches in case of seasonal tilt. May be an already discussed question. but, i couldn't find the solution. Thanks.

PVsyst's P50-P90 evaluation tool provides option to include inter-annual variability. But, how can I include uncertainty of radiation itself?

I am using 'Transposition Factor' tool for optimization of plane orientation. I could not create TF table using my hourly meteo file; PVsyst shows error, 'Please choose a valid Meteo file'. But the same hourly meteo file works for simulation. Kindly help me to sort out this issue. And, I am able to generate TF table using monthly meteo file. In this case, what would be the difference if I create TF table using monthly meteo file? Thanks.