Difference in PVGIS and meteonorm weather data on production

[hom]

Below is a screenshot of production when I used PVGIS weather data. for Norway, normally april is lower than may june july but when i used PVGIS weather for pvsol it shows like this, can anyone explain???

[developer_mo]

Hi hom,
thank you for reporting this case. The unusual value may be due to irregularities in the PVGIS data. For this reason, we currently recommend comparing the values with alternative climate data for the region and switching to these if appropriate. You may be interested in this related post.

Kind regards
Mikio

[developer_bh]

Dear hom,

 

thanks for reaching out to us.

• Does the monthly distirbution of global irradiation values look similiar to your chart for this PVGIS-location (You can see it via MeteoSyn > Details with the latest PVSOL) ?
• Sometimes there are missing timeperiods in the data, so I'd recommend to check your climate-data-file in MeteoSyn for missing periods, f.e. days with no global radiation at all.

If yes and no missing timeperiods:

As Mikio already pointed out there can be some irregularities in PVGIS data. These mainly regard temperature data on locations near the coast . In PVGIS 5.1 and older (called PVGIS-SARAH/ERA-Interim" in the source) there can be some more problems regarding the distribution of the global-irradiation data over the day.

However your problem does not look like one of these factors. It might be a problem with the satellite-rawdata which is collected to generate a typical meteorological year.

It is hard to reconstruct at this point why April is higher than May and June, we don't have the raw data from PVGIS.  If you want to investigate yourself you may have a look at https://re.jrc.ec.europa.eu/pvg_tools/en/ .

For now I'd recommend using another climate source for your area.

 

Best regards,

Ben