This document describes a solar tracking system that uses light sensors and a microcontroller to rotate a solar panel towards the sun for increased efficiency. It discusses two main tracking techniques - fixed control algorithms that calculate the sun's position based on time/date, and dynamic tracking that actively finds the sun's position. The system uses two LDR light sensors to detect sunlight and a motor driver controlled by a microcontroller to rotate the solar panel towards the brighter sensor. When constructed, the solar tracker was able to maintain the panel at an angle perpendicular to the sun, increasing power output by over 30% compared to a fixed panel.

1. BY-:Anugya Shukla

2. INTRODUCTION
As the range of applications for solar energy increases, so
does the need for improved materials and methods used to
harness this power source. There are several factors that
affect the efficiency of the collection process. Major
influences on overall efficiency include solar cell efficiency,
intensity of source radiation and storage techniques. The
materials used in solar cell manufacturing limit the
efficiency of a solar cell. This makes it particularly difficult
to make considerable improvements in the performance of
the cell Therefore, the most attainable method of
improving the performance of solar power collection is to
increase the mean intensity of radiation received from the
source.

3. There are three major approaches for maximizing power
extraction in medium and large scale systems. They are sun
tracking, maximum power point (MPP) tracking or both.

4. Components Required
The major components used in this
project are
•Microcontroller
•Motor driver
•DC Motor
•LDR

5. Basic Block Diagram
Solar
panel
DC
LDR MOTOR
MICROCONTROLLER

6. OBJECTIVE
 If we could configure a solar cell so that it faces the sun
continually as it moves across the sky from east to
west, we could get the most electrical energy possible.
 Going outside to a solar cell every hour to turn it
toward the sun might be possible, but this would still
not be an efficient method. A photo sensor is
employed to control the solar cell tracking system.

7. TRACKING TECHNIQUES
The two general forms of tracking used are:
 Fixed control algorithms
 Dynamic tracking

8. FIXED CONTROL ALGORITHM
In the fixed control algorithm systems, the path of
the sun is determined by referencing an algorithm
that calculates the position of the sun for each time
period. That is, the control system does not actively
find the sun's position but works it out given the
current time, day, month, and year.

9. DYNAMIC TRACKING
The dynamic tracking system, on the other
hand, actively searches for the sun's position
at any time of day (or night).Common to both
forms of tracking is the control system. This
system consists of some method of Direction
control, such as DC motors, stepper motors,
and servo motors, which are directed by a
control circuit, either digital or analog.

10. LIGHT SENSOR AND MOTOR DRIVER

11. LIGHT SENSOR
 Light sensors are among the most common sensor
type. The simplest optical sensor is a photoresistor
which may be a cadmium sulfide (CdS) type or a
gallium arsenide (GaAs)type .

12. The sun tracker uses a cadmium
sulfide (CdS) photocell for light
sensing. This is the least expensive
and least complex type of light
sensor . The CdS photocell is a
passive component whose
resistance is inversely proportional
to the amount of light intensity
directed toward it. Cds Photocell
Circuit

13. D.C. MOTORS
 A DC motor is designed to run on DC electric power.
the most common DC motor types are the brushed
and brushless types, which use internal and external
commutation respectively to reverse the current in the
windings in synchronism with rotation.
 Here DC motor is used to rotate the solar panel in
direction of sun where the sun rays fall maximum

15. • In this project we have used two LDR sensors.
•These sensors give analog output.
•The analog output is given to the micro
controller.
•The micro controller compares the analog
voltage and then decides upon the motion of the
motor.
•If the light on a particular LDR is greater, then
the micro controller gives the command to the
motor driver to rotate the motor in a direction
such that the both LDR receives equal light.

18. A Solar panel (also solar module,
photovoltaic module or photovoltaic panel) is
a packaged, connected assembly
of photovoltaic cells. The solar panel can be
used as a component of a larger photovoltaic
system to generate and supply electricity in
commercial and residential applications. Each
panel is rated by its DC output power under
standard test conditions, and typically ranges
from 100 to 450 watts. The efficiency of a
panel determines the area of a panel given the
same rated output - an 8% efficient 230 watt
panel will have twice the area of a 16%
efficient 230 watt panel. SOLAR PANEL

19. ENERGY STORAGE SYSTEM
 A capacitor is employed to store the energy generated
by a solar panel(by converting solar energy into
electrical energy).
 Now this stored energy is can be utilize any where but
in our project we have used to light a LED.

21. The portions consisted of light
detection, motor driving ,software
tracking, and software enhancements.
Building and testing smaller sections
of the system made the project more
manageable and increased efficiency
by decreasing debugging time.

23. POWER PLANTS

24. STREET LIGHT

25. Home application

28. CONCLUSION
. A solar tracker is designed employing the new
principle of using small solar cells to function as
self-adjusting light sensors, providing a variable
indication of their relative angle to the sun by
detecting their voltage output. By using this method,
the solar tracker was successful in maintaining a
solar array at a sufficiently perpendicular angle to
the sun. The power increase gained over a fixed
horizontal array was in excess of 30%.

29. Future Scope
Although there are many reasons to believe that
the future of solar energy is bright and coming soon, the
answer really lies in the hands of the world's citizens. In a
world largely governed by economics and politics, what
ordinary citizens choose to buy and support will dictate
the trends of the future. By installing solar panels,
donating to research organizations involved in alternative
energies, majoring in science or engineering, and voting
for measures that give money to alternate energy
development, anyone can influence
the future of solar energy.

30. Any Questions