I think that the data you need is available for outside face of any surface. This is a list from my model's .rdd
file:
Output:Variable,*,Surface Outside Normal Azimuth Angle,hourly; !- Zone Average [deg]
Output:Variable,*,Surface Outside Face Sunlit Area,hourly; !- Zone Average [m2]
Output:Variable,*,Surface Outside Face Sunlit Fraction,hourly; !- Zone Average []
Output:Variable,*,Surface Outside Face Incident Solar Radiation Rate per Area,hourly; !- Zone Average [W/m2]
Output:Variable,*,Surface Outside Face Incident Beam Solar Radiation Rate per Area,hourly; !- Zone Average [W/m2]
Output:Variable,*,Surface Outside Face Incident Sky Diffuse Solar Radiation Rate per Area,hourly; !- Zone Average [W/m2]
Output:Variable,*,Surface Outside Face Incident Ground Diffuse Solar Radiation Rate per Area,hourly; !- Zone Average [W/m2]
Output:Variable,*,Surface Outside Face Beam Solar Incident Angle Cosine Value,hourly; !- Zone Average []
Output:Variable,*,Surface Outside Face Incident Sky Diffuse Ground Reflected Solar Radiation Rate per Area,hourly; !- Zone Average [W/m2]
Output:Variable,*,Surface Outside Face Incident Sky Diffuse Surface Reflected Solar Radiation Rate per Area,hourly; !- Zone Average [W/m2]
Output:Variable,*,Surface Outside Face Incident Beam To Beam Surface Reflected Solar Radiation Rate per Area,hourly; !- Zone Average [W/m2]
Output:Variable,*,Surface Outside Face Incident Beam To Diffuse Surface Reflected Solar Radiation Rate per Area,hourly; !- Zone Average [W/m2]
Output:Variable,*,Surface Outside Face Incident Beam To Diffuse Ground Reflected Solar Radiation Rate per Area,hourly; !- Zone Average [W/m2]