What Parameters used to calculate GHI and PV Power?

#1

Any ideas which all parameters are used to calculate the

  1. GHI
    - Is it global radiation data only or
    - does it include weather data as well (air and ground temp, wind speed and humidity)

  2. PV Power
    - GHI
    - Weather data (METEO)
    - SP Capacity (4v, 6 or 10v)
    - Tilt and Azimuth

Does it consider shading, or do we have to add it as optional from SRTM3 data?

Any inputs would be helpful.

Thank you…