Grae

Hi, We have a simulation in Australia, where we found a change in IAM values between PVsyst version 6.42 and version 6.52, which we investigated. We ensured that the .pan file and IAM was the same between the two variants along with the meteo file to ensure a like for like test. We found whilst analysing the results that although the main GII on the PVsyst report was the same, the GII value in the 'Annual Yield', 'Detailed study of IAM (Incidence Angle Modifier)', this was an unexpected outcome. We see in the release notes that some work has been done on the IAM coding in 6.43, ‘Fixed errors’ point 2. Please can you confirm if this is the reason why we are seeing the changes. Many thanks, Grae

Hi, We also seem to be getting a similar issue (v6.42), when changing the inverter efficiency values. We have re-installed PVsyst a few times, however the issue seems to creep in but not for user. The file errors out with a blank error message and appears to corrupt the file if you save after. Screenshot attached of this in progress. Many thanks, Grae

Hi, We have been looking into the .ond files and utilising the efficiency curves for different voltages. We are currently not using the functionality of efficiency for 3 voltages as we seem to have an issue in generating the curves. It appears when you set the voltage to a certain threshold, you have to set all three voltages manually as they are not generated from the first point entered. Is this an issue, is PVsyst able to interpolate the remaining two efficiency curves, from the original defined efficiency curve (i.e. set the max efficiency curve at a low / mid / high voltage and the other two curves are generated based on this)? When defining all three voltages with the same Max Euro efficiencies, we obtain the same loss as not using these curves (i.e. having this option ticked or unticked). Sometimes we have seen the profile curves setting a very different profile curve to the curves observed on the datasheets. However not all datasheets have these curves which makes this checking and definition impossible. Many thanks, Grae

Hi, We have been modelling rooftop systems and have found that there is always a near shading loss regardless of objects. We simplified these to just a single module flat and found even then we would see a loss. The loss is small at 0.136% but we cannot understand why there is a loss. We also noticed that with a 7° tilt this loss was reduced which we also cannot explain. Any ideas about why this shading loss occur ? Many thanks