A huge difference in GHI Data of Meteonorm 8.1 data

[Umair Hashmi]

I have found the data provided in latest Meteonorm 8.1 have a huge difference in GHI. This seems to be an error in data and drastically reduce solar generation. 

 

For example, for the Lahore City the average GHI in previous meteonorm versions and other data sources are around 1700Wh/m² while in Meteo 8.1, it is around 1525kWh/m² 

Similarly, 

For the Islamabad Region the average GHI in previous meteonorm versions and other data sources are around 1735Wh/m² while in Meteo 8.1, it is around 1550kWh/m² 

Another example

In Khanewal-Punjab region the average GHI in previous meteonorm versions and other data sources are above 1800Wh/m² while in Meteo 8.1, it is around 1650kWh/m² 

Do we have any option to get previous metenorm data in latest version? or is there any suggestion to overcome this issue?

[Agnes Bridel]

Meteonorm versions are associated to the PVsyst version. You will have to run previous PVsyst version to get previous meteonorm data, i.e. PVsyst 7.1 to use Meteonorm 7.3. 

 

Best regards,