Annual to Hourly values of DNI

Dear all,
What equations are used to convert annual value of DNI to hourly values.... kindly refer some link

Hello,
The equations that SAM uses to calculate the system's hourly output from the DNI values in the weather file depend on what kind of system you are modeling. You can find documentation for each of SAM's CSP models in the Performance Model Documentation page of this website:

• 
  /performance 

Best regards,

Paul.