Calculating Energy efficient Tilt Angle for Solar Panel

As I have already discussed in the previous post that i am adding single axis tracking to my solar panel and the Altitude angle (Tilt angle) shall be adjusted in Summer and Winter to get the maximum efficiency out of the solar panels. Here are the Rule of thumb for best tilt angle.


 SEASON------------------- ANGLE TILT CALCULATION

Winter    --------------------  (Latitude x 0.89) + 24 degrees
Summer  -------------------  (Latitude x  1.05) - 24.3 degrees
Spring & falls --------------   (Latitude x0.98) - 2.3 degrees

Pakistan resides in Northern hemisphere so the Solar panel should be toward the TRUE SOUTH. The Tilt angle is calculated from the Horizon.

Example:

City :  SADIQABAD, PAKISTAN
Latitude (from google) : 28.1700 N  
Tilt Angle for Winter= (28.17 x 0.89) +24 degree  = 49.07
                               = Say 49 degree  from horizon or   (90- 49 = 41 degree) from the vertical
Tilt Angle for Spring & Fall=  (28.17 x 0.98)-2.3 = 25.306
                                 =  Say 25 degree   from horizon or (90- 25 = 65 degree) from the vertical
Tilt Angle for Summer= (28.17 x 1.05) -24.3 degree  = 5.27
                                = Say 5 degree from horizon or (90-5 = 85 degree) from the vertical


As these solar panels shall be installed in Karachi so:

City :  KARACHI, PAKISTAN
Latitude (from google) : 24.8508 N  
Tilt Angle for Winter= (24.8508 x 0.89) +24 degree  = 46.11
                              = Say 46 degree  from horizon or (90-46 = 44 degree ) from vertical
Tilt Angle for Spring & Fall=  (24.8508 x 0.98)-2.3
                                 =  Say 23 degree from horizon or (90-23= 67 degree) from vertical
Tilt Angle for Summer= (24.8508 x 1.05) -24.3 degree  = 1.79
                                 = Say 1.8 degree from horizon or (90-1.8=88.2 degree) from vertical