The generation of electricity from the rooftop solar panel system depends on many parameters such as –
Location of the rooftop solar (part of the country)
Quality of equipment used
No. of sunshine hours
Temperature and irradiance (the strength of sunlight received)
PV module tilt angle and orientation
Module cleaning, and other maintenance activities
The daily energy generation will be dependent on the weather conditions such as temperature, solar irradiance, etc., and these may not be same every day.