Introduction of Solar Tracking system
Daily and Seasonal motion of sun
History of solar tracking system
Types of solar Tracker
Components of solar tracking system
Flowchart of tracking system
Experimental Explanation of automatic tracking
Recent trend of solar tracking system
Future Research direction
3. What is Solar Tracking System?
A solar tracker is a device that
orients a payload toward the Sun.
Payloads are usually solar
panels, parabolic troughs, fresnel
reflectors, lenses or the mirrors of
Basically, trackers are used to
minimize the angle of
incidence between the incoming
sunlight and a photovoltaic panel.
4. Why we require Solar Tracking?
The energy contributed by
the direct beam drops off
with the cosine of the
angle between the
incoming light and the
Direct power lost (%) due
to misalignment (angle i )
Lost = 1 - cos(i)
5. i Lost i Lost
0° 0% 23.4° 8.3%
1° 0.015% 30° 13.4%
3° 0.14% 45° 30%
8° 1% 60° >50%
15° 3.4% 75° >75%
• Trackers that have accuracies of ± 5° can deliver greater than 99.6% of the
energy delivered by the direct beam plus 100% of the diffuse light.
• As a result, high accuracy tracking is not typically used in non-
concentrating PV applications.
6. Daily and Seasonal motion of
1. Daily east-west motion of the Sun:
The Sun travels through 360 degrees east to west per day,
the visible portion is 180 degrees during an average 1/2
day period (more in spring and summer; less, in fall and
Local horizon effects reduce this somewhat, making the
effective motion about 150 degrees.
A solar panel in a fixed orientation between the dawn and
sunset extremes will see a motion of 75 degrees to either
side, and thus, will lose over 75% of the energy in the
morning and evening.
Rotating the panels to the east and west can help
recapture those losses.
A tracker that only attempts to compensate for the east-
7. 2. Seasonal north-south
motion of the Sun:
Due to the tilt of the
Earth's axis, the Sun also
moves through 46 degrees
north and south during a
The same set of panels
set at the midpoint
between the two local
extremes will thus see the
Sun move 23 degrees on
Conversely a vertically or
horizontally aligned single-
axis tracker will lose
considerably more as a
result of these seasonal
variations in the Sun's
8. Who develops the idea of solar
Researcher Description of the system Year
C. Finster The first ever developed solar tracker - Completely mechanical and poorly
performing system with too little real life
A. Saavedra An improved version of the previous (Finster's) - Automatically controlled
system with a turning pyro-heliometer to
determine the position of the sun.
The position of the sun was given by the contribution of several individual
mirrors reaching a reasonably high
accuracy with an admissible error between 0.5° and 1°.
First commercial solar tracker with both the limiting position and excess
heat switches – Self-contained with an
electrical control mechanism to detect the sun.
The system using a microprocessor to adaptively adjust both the tracking
and the solar collector units for maximum
solar energy collection.
9. Types of solar tracking system
and gear trains
uses a low
10. Based on Sun
tilted single axis
tip-tilt dual axis
11. 1. Single axis tracking system
HSAT-The axis of rotation is horizontal with respect to the ground.
VSAT-The axis of rotation is vertical with respect to the ground.
TSAT- Face of the module oriented parallel to the axis of rotation.
PSAT-Panels located to polar axis.
2. Duel Axis tracking system
TTDAT- Normally the east–west movement is driven by rotating the
array around the top of the pole. On top of the rotating bearing is a T-
or H-shaped mechanism that provides vertical rotation of the panels
and provides the main mounting points for the array.
AADAT-Instead of rotating the array around the top of the pole, AADAT
systems can use a large ring mounted on the ground with the array
mounted on a series of rollers. its primary axis (the azimuth axis)
vertical to the ground. The secondary axis, often called elevation axis,
is then typically normal to the primary axis
12. Components of solar tracking system
-DC electric motor, voltage mode driven, with current
monitoring, without movement sensors (speed or position)
- a motor control system of intelligent drive type, completely
digital, that allows the implementation of the digital control of
the motor as well as the implementation in a dedicated motion
control language of the PV panel orientation application
- a measurement system for light intensity applied to the
PV panel, representing the sensor that commands the solar
14. How the automatic tracker
Automatic tracker consists of a optical sensors
Based on the incident sun rays, optical sensors
give the command to the processor
Processor then carry that command and deliver it
to the actuators which would basically orient the
panel as per the specifications.
16. • Graph presented the variations of the received signals from the two LEDs
with respect to trigger value.
• Here, a light source moves in front of the PV panel and the difference in
signal can be used for the decision taking module to move the panel to the
right or to the left.
17. • Based on the difference between the two signals received from the two LEDs,
compared with two imposed trigger values (programmable by the user), the
command signals for the movement of the PV panel to the left or to the right were
18. • The variations of the signals received from the LEDs in stand-by state,
when the difference between the two signals is lower than the trigger
value for executing a movement command.
• We should notice that in the stand-by state no movement command
19. Recent trend of solar tracker
Tracking was very cost effective in the past when
photovoltaic modules were expensive compared to today.
Because they were expensive, it was important to use
tracking to minimize the number of panels used in a
system with a given power output.
But as panels get cheaper, the cost effectiveness of
tracking VS using a greater number of panels decreases.
The cost of energy generated from a PV tracking system is
higher than the energy produced from a fixed system
because of the running cost and the initial cost of the
tracking system, which makes their economic advantages
Still there are lot of advancement required to make it
Single Axis Tracking can improve the efficiency up to 25%
while double axis tracking system can further improve the
efficiency up to 40% if worked perfectly.
20. Payback VS Type of Solar tracking
Type of solar tracker Cost per watt power Projected pay back
Fixed solar panel $2-2.4 1.5 to 3.5 years for
crystalline silicon PV
1 to 1.5 years for thin
Single axis solar tracking
$1-1.7 3 years of payback on
Dual axis solar tracking
$0.36 3.5 to 5 years of payback
cost on tracker
Passive solar tracking
$1.2-2 Approximately 5 years of
21. Future research direction
Future research in double axis STS using the closed loop
tracking control units could significantly improve the overall
electrical performance for large scale solar energy
harvesting devices that feature STS.
Two separate axis control system that would benefit the
solar panel and increase its rate of generating energy.
The goal of the control system is to automatically position
and tilt the solar panel towards the strongest line of light.
The first axis is in charge of tilting the solar panel left and
right towards the strongest side of light.
The second axis enables rotation of the entire system so
that the first axis can tilt in the direction of light with the
This configuration allows the dual axis solar panel to
consistently stay in the highest intensity of light in the area,
and generates more energy than its stationary counterpart.
Design of a Solar Tracker System for PV Power Plants by Tiberiu
Tudorache, Liviu Kreindler
Design of a Solar Tracking System for Renewable Energy by Jeng-Nan
Juang and R. Radharamanan
Automatic dual axis solar tracker by walled seeda and Elkhatib kamal
Recent advancements and challenges in Solar Tracking Systems (STS): A
review by Walter Nsengiyumva, Shi Guo Chen, Lihua Hu, Xueyong Chen
Solar tracking methods to maximize PV system output – A review of the
methods adopted in recent decade by Vijayan Sumathia,, R. Jayapragasha,
Abhinav Bakshib, Praveen Kumar Akellab
Solar Photovoltaic by C S Solanki