DNI data problem

Hello!
I'd need your help to understand a problem.
I'm using a weather data file for my location of interest (taken from meteonorm in the TM3 format) that has been modified with the sam macro (file in attachment). If I open the meteo file, the data are correct, but when I display the Beam hourly normal irradiance after the simulation has finished, the values in the graph are much lower (like half of the real value). So I don't know if the thermal output is correct or not.
Can I ask you which kind of problem can have occurred?

Thank you very much, have a nice day!

Valeria

Dear Valeria,

If you are modeling a photovoltaic system, the default inputs include a 5% loss factor for module soiling. Please try changing the value of the loss factor (on the Losses page) to zero and see if the results are more like what you expect. The loss values are for each of the twelve months in a year, so to change them you will need to click the "Edit values" button, and then change the loss value for each month from 5 to zero.

Best regards,
Paul.