A collector with a tilt angle of 60 is installed on GT campus at Atlanta, GA (Longitude: 84.39W, Latitude: 33.76N, and elevation 320m ). The collector faces due south, and the foreground is concrete. Find the total solar irradiance on the collector at 11:00 am on 08/21. Show the calculation steps. Optional (2 bonus points): Make a spreadsheet in Excel for the calculation of total solar irradiance in different scenarios (location, time, tilt angle, etc.). Use this spreadsheet (instead of the equations on lecture slides) to determine the optimal tilt angle 2 for solar power collectors (facing due south) at Atlanta. Hint: draw a curve of different total solar irradiance versus different tilt angles and find the peak