Error using EPW weather file downloaded from EnergyPlus

Hello! 

I am a international graduate student here in the US and I am trying to simulate in SAM using weather file for Kuwait. The weather file was taken from EnergyPlus and is in EPW format.

Whenever I run the simulation I get this error:
Simulation pvwattsv7 failed :beam irradiance exceeded extraterrestrial value at record [y:1995 m:1 d:24 h:11] 

How can I fix this? 

Thanks! 
Ali 

Hi Ali,

Those error messages indicate that there is a problem with the direct normal irradiance (DNI, or beam irradiance) data for a few of the 8760 hours in the weather file. It looks like one value is 1,910 W/m2, which is higher than you would expect, and there are several hours with negative DNI values. For example, you can see in this plot (click View data on the Location and Resource page) that there are some negative DNI values on April 25:





You could ignore those errors because the only affect a few hours of the year, or you could try a weather file from a different source like the PVGIS  source listed here: sam.nrel.gov/weather-data .

Best regards,
Paul.