Irradiance Components for PV Models

I want to use my own weather file (in TM3 format). 
My question is - is Beam irradiance data mandatory? I want to use Global and Diffuse irradiances. Does the TM3 format or SAM itself allow me to skip 
Beam components? Beam data are more expensive to get and my test project is PV technology, guessing no Beam irradiation is needed for simulation...
SAM's detailed photovoltaic model allows you to choose which irradiance components from the weather file it should use. To see the options, go to the Location and Resource page, and expand the Albedo - Sky Diffuse Model - Irradiance Data (Advanced) panel. If your weather file does not have DNI data, you can choose the GHI and DHI option. SAM will calculate a DNI value and report it in the time series results. The PV model requires DNI and DHI as input, so if the weather file is missing one of those components, SAM calculates the value of the missing component.
Also, you may want to use the SAM CSV format for your weather data. It is a simpler format than the TMY3 format and only contains the data SAM requires. You can use the Weather File Converter macro in SAM to convert files from TMY3 to SAM CSV format. To see the macro, click the Macros button at the bottom left of the SAM main window.

Best regards,

Paul.