Automatic solar tracking system

The elevation angle
is the angle made by the sun with the horizon. The elevation angle is 0 degree 
at sunrise and 90 degrees around noontime, at the equator. The elevation angle is different at a 
different time of the day and different for different latitudes. The depicted formula can be used to 
determine the elevation angle. 
𝛼 = 90 + 𝜑 − 𝛿
When the equation above gives a number greater than 90° then subtract the result from 180°. It 
means the sun at solar noon is coming from the south as is typical the northern hemisphere. 
φ is the latitude of the location of interest (
+
ve for the northern hemisphere and 
−
ve for the 
southern hemisphere). δ is the declination angle, which depends on the day of the year.
Figure 3.3: Angle of elevation and zenith angle 
Zenith angle
is akin with elevation angle. The only difference being it is measured along the 
vertical. Therefore, it’s the angle between the sun and the vertical i.e. Zenith Angle = 90
°
– 
elevation angle. 
𝜁 = 90° − 𝛼
 

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THEORITICAL BACKGROUND OF SOLAR TRACKER 
17
AEIE, RCCIIT 
Azimuthal Angle
, this is the compass direction from which the sunlight is coming. At solar noon, 
the sun is directly south in the northern hemisphere and directly north in the southern hemisphere. 
The azimuth angle varies throughout the day. At the equinoxes, the sun rises directly east and sets 
directly west regardless of the latitude. Therefore, the azimuth angles are 90 degrees at sunrise and 
270 degrees at sunset. 
Sunrise and Sunset time can be formulated by the following formulas- 
Sunrise
= 12 −
1
15°
cos
−1
(− tan 𝜑 tan 𝛿) −
𝑇𝐶
60
Sunset
= 12 +
1
15°
cos
−1
(− tan 𝜑 tan 𝛿) −
𝑇𝐶
60
Where φ being the latitude of the place, δ being the declination angle and TC is the Time 
Correction.[8]