This document appears to be a project report submitted by three students - Mr. Akshay Thakur, Ms. Juhi Kamdar, and Mr. Kalpesh Deshmukh - for their Bachelor of Engineering degree. It describes the design and development of a sun tracking solar panel system. The project was supervised by Mr. Sharad P. Jadhav and submitted to the Department of Instrumentation Engineering at Ramrao Adik Institute of Technology to fulfill degree requirements for the University of Mumbai.

1. Sun Tracking Solar Panel
Submitted in partial fulfillment of the requirements
of the degree of
Bachelor of Engineering
by
Mr. Akshay Thakur Roll No. 12IN1037
Ms. Juhi Kamdar Roll No. 12IN1011
Mr. Kalpesh Deshmukh Roll No. 12IN1041
Supervisor
Mr. Sharad P. Jadhav
by
Department of Instrumentation Engineering
Ramrao Adik Institute Of Technology
Dr. D. Y. Patil Vidyanagar, Sector 7, Nerul, Navi Mumbai 400706.
(Affiliated to University of Mumbai)
2015

2. Ramrao Adik Institute of Technology
CERTIFICATE
This is to certify that, the synopsis titled
“Sun Tracking Solar Panel”
is a bonafide work done by
Mr. Akshay Thakur
Ms. Juhi Kamdar
Mr. Kalpesh Deshmukh
and is submitted in the partial fulfillment of the requirement for the
degree of
Bachelor of Engineering
in
Instrumentation Engineering
to the
University of Mumbai
Supervisor
Mr. Sharad P. Jadhav
Project Co-ordinator Head of Department Principal
(Mr. Mahesh N. Parihar ) (Mr. Sharad P. Jadhav) (Dr. Ramesh Vasappanavara)

3. Declaration
We declare that this written submission represents my ideas in my own words and where
other’s ideas or words have been included,We have adequately cited and referenced the original
sources. We also declare that We have adhered to all principles of academic honesty and
integrity and have not misrepresented or fabricated or falsified any idea/data/fact/source in my
submission. We understand that any violation of the above will be cause for disciplinary action
by the Institute and can also evoke penal action from the sources which have thus not been
properly cited or from whom proper permission has not been taken when needed.
..............................
(Mr. Akshay V. Thakur and Roll No. 12IN1037 )
..............................
(Ms. Juhi G. Kamdar and Roll No. 12IN1011)
..............................
(Mr. Kalpesh K. Deshmukh and Roll No. 12IN1041)
Date :

4. B. E. Project Stage I Approval
This project report entitled ”Sun Tracking Solar Panel” by Mr. Akshay V. Thakur ,Ms.
Juhi G. Kamdar and Mr. Kalpesh K. Deshmukh is approved for the degree of Bachelor’s
Degree in Instrumentation Engineering, University of Mumbai.
Examiners :
1. ........................ ... . ..
2. ........................ ... . ..
Supervisors :
1. ........................ ... . ..
2. ........................ ... . ..
Chairman
......................... ... . .
Date :
Place :

5. Acknowledgments
With great pleasure, We avail this opportunity to express my profound gratitude and
deep regards to my project supervisior Mr. Sharad P.Jadhav for their spirited guidance, mon-
itoring and constant encouragement throughout the completion of this seminar report. We have
deep sense of admiration for their innate goodness and inexhaustible enthusiasm, it helped me
to work in right direction to attain desired objective.
We have also thankful to Mr. M.N.Parihar, Project Co-ordinator and Mr. Sharad P.
Jadhav, Head of Department of Instrumentation Engineering, RAIT, Nerul for his generous
support, devoting their valuable time and helped me in all possible ways towards successful
completion of this work. I thank all those who have contributed directly or indirectly to this
work.
We take this privilege to express my sincere thanks to Dr. Ramesh Vasappanavara, Prin-
cipal, RAIT for their support, encouragement and providing the much necessary facilities. We
extend thanks to my friends who have supported in every stage of these report. We cannot end
without thanking my lovely family for their encouragement.
Date Signature

6. Abstract
Our project Sun Tracking Solar Panel will include the design and construction of an
Arduino-based solar panel tracking system. Solar tracking allows more energy to be produced
because the solar array is able to remain aligned to the sun. Solar energy is rapidly gaining
popularity as an important means of expanding renewable energy resources. As such, it is vital
that those in engineering fields understand the technologies associated with this area.
This system builds upon topics learned in this course. The aim of the project is to keep the
solar photovoltaic panel perpendicular to the sun throughout the year in order to make it more
efficient. The dual axis solar photovoltaic panel takes astronomical data as reference and the
tracking system has the capability to always point the solar array toward the sun and can be
installed in various regions with minor modifications. The vertical and horizontal motion of
the panel is obtained by taking altitude angle and azimuth angle as reference. The Arduino has
been used to control the position of DC servo motors. The mathematical simulation control
of dual axis solar tracking system ensures the point to point motion of the DC motors while
tracking the sun.

7. Contents
1 Introduction 1
1.1 Motivation And Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 Organisation of report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 Literature Survey 4
3 Concepts of Solar Radiation 7
4 Functional Block Diagram 10
5 Design Methodology 13
5.1 Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.1.1 Solar panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.1.2 Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.1.3 DC Servo Motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.1.4 Arduino Uno . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5.2 Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
5.2.1 Arduino Software (IDE) . . . . . . . . . . . . . . . . . . . . . . . . . 21
6 Work Plan 24
7 Conclusion 25
Bibliography 26
ii

8. List of Figures
1.1 A curve for the relationship between the solar radiation and the solar angle of
incidence.[2] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
3.1 The Declination Angles.[2] . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.2 Solar altitudes and azimuths typical behavior of sun path.[2] . . . . . . . . . . 9
4.1 Block diagram of Sun Tracking Solar Panel.[2] . . . . . . . . . . . . . . . . . 11
5.1 Solar Panel.[2] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.2 Dual Axis tracker [2] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.3 Light Dependent Resistor (LDR).[2] . . . . . . . . . . . . . . . . . . . . . . . 17
5.4 Schematic diagram of dc servo motor . . . . . . . . . . . . . . . . . . . . . . 18
5.5 DC Servo Motor.[2] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5.6 Arduino Uno on board component.[2] . . . . . . . . . . . . . . . . . . . . . . 19
5.7 Arduino Software logo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
iii

9. Chapter 1
Introduction
The world population is increasing day by day and the demand for energy is increasing ac-
cordingly. Oil and coal as the main source of energy nowadays, is expected to end up from the
world during the recent century which explores a serious problem in providing the humanity
with an affordable and reliable source of energy. The need of the hour is renewable energy
resources with cheap running costs. Solar energy is considered as one of the main energy re-
sources in warm countries[1].
In general, India has a relatively long sunny day for more than ten months and partly cloudy
sky for most of the days of the rest two months. This makes our country, especially the desert
sides in the west, which include Rajasthan, Gujarat, Madhya Pradesh etc. very rich is solar
energy. Many projects have been done on using photovoltaic cells in collecting solar radiation
and converting it into electrical energy but most of these projects did not take into account the
difference of the sun angle of incidence by installing the panels in a fixed orientation which
influences very highly the solar energy collected by the panel.
As we know that the angle of inclination ranges between -90 degree after sun rise and +90
degree before sun set passing with 0 degree at noon. This makes the collected solar radiation to
be 0 percent at sun rise and sun set and 100 percent at noon. This variation of solar radiations
collection leads the photovoltaic panel to lose more than 40 percent of the collected energy.The
1

10. Sun Tracking Solar System
yearly sun path at the latitude of30 degree. One can estimate the exact position of sun in every
day Month and at any time during the day.
Figure 1.1: A curve for the relationship between the solar radiation and the solar angle of
incidence.[2]
The position is decided by two angles in spherical coordinates; the Altitude angle which is
the angle of the sun in the vertical plane in which the sun lies, and the Azimuth angle which
represents the angle of the projected position of the sun in the horizontal plane. These two
angles will be discussed deeply later in this document. Fig. 1.1 shows a curve for the relation-
ship between the solar radiation and the solar angle of incidence. This figure shows that solar
radiations falling on the solar array will be maximum when the angle of incidence on the panel
is 00 which means that the panel is perpendicular to the sun. The daily average solar energy
incident over India varies from 4 to 7 kWh/m square with about 15002000 sunshine hours per
year (depending upon location), which is far more than current total energy consumption.
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11. Sun Tracking Solar System
1.1 Motivation And Objectives
• Development of in-house setup for practical exposure of the tracking system.
• Advantages of solar tracker system over fixed tilt solar system.
1. Increase in 25-30 percent power output.
2. Improves efficiency by 30 percent would be the equivalent to solar panels with a 30
percent higher efficiency rating.
3. Follows the sun‘s trajectory and ensure that the solar panels are positioned for max-
imum exposure to sunlight.
• Use of renewable energy to produce electricity.
1.2 Organisation of report
After the brief introduction motivation and contribution of the project, the rest of the report is
organized as follows: chapter 2 includes in the literature survey. Chapter 3 explores the detail
about the concepts on solar radiations .In Chapter 4, the functional block diagram is explained.
Chapter 5 consists of design methodology. Chapter 6 is based on our work plan and finally
chapter 7 concludes the project.
Ramrao Adik Institute of Technology 3

12. Chapter 2
Literature Survey
After doing rigorous literature survey, the motivation of the project is decided. In the literature
standard journal papers and books are referred.
In the paper[3],” IMPLEMENTATION OF A PROTOTYPE FOR A TRADITIONAL SO-
LAR TRACKING SYSTEM” by Nader Barsoum published in the 2009 Third UKSim Euro-
pean Symposium on Computer Modeling and Simulation describes in detail the design and
construction of a prototype for solar tracking system with two degrees of freedom, which
detects the sunlight using photocells. The control circuit for the solar tracker is based on a
Arduino. This is programmed to detect the sunlight through the photocells and then actuate the
motor to position the solar panel where it can receive maximum sunlight. This paper is about
moving a solar panel along with the direction of sunlight; it uses a gear motor to control the
position of the solar panel, which obtains its data from a Arduino. The objective is to design
and implement an automated, double-axis solartracking mechanism using embedded system
design in order to optimize the efficiency of overall solar energy output.
In the paper[4] entitled,” Design and Construction of an Automatic Solar Tracking System
by Md. Tanvir Arafat Khan, S.M. Shahrear Tanzil, Rifat Rahman, S M Shafiul Alam published
in 6th International Conference on Electrical and Computer Engineering ICECE 2010, 18-20
December 2010, Dhaka, Bangladesh describes a Arduino based design methodology of an au-
4

13. Sun Tracking Solar System
tomatic solar tracker. Light dependent resistors are used as the sensors of the solar tracker. The
designed tracker has precise control mechanism which will provide three ways of controlling
system. A small prototype of solar tracking system is also constructed to implement the design
methodology presented here. In this paper the design methodology of a Arduino based simple
and easily programmed automatic solar tracker is presented. A prototype of automatic solar
tracker ensures feasibility of this design methodology.
In the paper[5],” IMPLEMENTATION OF A PROTOTYPE FOR A TRADITIONAL SO-
LAR TRACKING SYSTEM” by Nader Barsoum published in the 2009 Third UKSim Euro-
pean Symposium on Computer Modeling and Simulation describes in detail the design and
construction of a prototype for solar tracking system with two degrees of freedom, which
detects the sunlight using photocells. The control circuit for the solar tracker is based on a
Arduino. This is programmed to detect the sunlight through the photocells and then actuate the
motor to position the solar panel where it can receive maximum sunlight. This paper is about
moving a solar panel along with the direction of sunlight; it uses a gear motor to control the
position of the solar panel, which obtains its data from a Arduino. The objective is to design
and implement an automated, double-axis solartracking mechanism using embedded system
design in order to optimize the efficiency of overall solar energy output.
In the paper[6] entiled,”Arduino Based Solar Tracking System” by Aleksandar Stjepanovic,
Sladjana Stjepanovic, Ferid Softic, Zlatko Bundalo published in Serbia,Nis,October 7-9, 2009
describes the design and construction of a microcontroller based solar panel tracking system.
Solar tracking allows more energy to be produce because the solar array is able to remain
aligned to the sun. The paper begins with presenting background theory in light sensors and
stepper motors as they apply to the project.In the conclusions are given discussions of design
results. The paper begins with presenting background theory, light sensors and stepper motors
as they apply to the project. The paper continues with specific design methodologies pertain-
ing to photocells, stepper motors and drivers, microcontroller selection, voltage regulation,
physical construction, and a software/system operation explanation.The paper concludes with
a discussion of design results and future work.
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14. Sun Tracking Solar System
In the paper[7] entitled,” Microcontroller-Based Two-Axis Solar Tracking System” by Lwin
Lwin Oo and Nang Kaythi Hlaing published in Second International Conference on Computer
Research and Development describes to develop and implement a prototype of two axis solar
tracking system based on a PIC microcontroller. The parabolic reflector or parabolic dish is
constructed around two feed diameter to capture the suns energy. The focus of the parabolic
reflector is theoretically calculated down to an infinitesimally small point to get extremely high
temperature. This two axis auto-tracking system has also been constructed using PIC 16F84A
microcontroller. The assembly programming language is used to interface the PIC with two-
axis solar tracking system. The temperature at the focus of the parabolic reflector is measured
with temperature probes. This auto-tracking system is controlled with two 12V, 6W DC gear
box motors. The five light sensors (LDR) are used to track the sun and to start the operation
(Day/Night operation). Time Delays are used for stepping the motor and reaching the original
position of the reflector. The two-axis solar tracking system is constructed with both hardware
and software implementations. The designs of the gear and the parabolic reflector are carefully
considered and precisely calculated.
Ramrao Adik Institute of Technology 6

15. Chapter 3
Concepts of Solar Radiation
Before talking about the solar tracking systems, we will review some basic concepts concerning
solar radiation and mention some important values to better understand the results of this work.
The sun, at an estimated temperature of 5800 K, emits high amounts of energy in the form
of radiation, which reaches the planets of the solar system. Sunlight has two components,
the direct beam and diffuse beam. Direct radiation (also called beam radiation) is the solar
radiation of the sun that has not been scattered (causes shadow). Direct beam carries about 90
percent of the solar energy, and the ”diffuse sunlight” that carries the remainder. The diffuse
portion is the blue sky on a clear day and increases as a proportion on cloudy days. The
diffuse radiation is the sun radiation that has been scattered (complete radiation on cloudy
days). Reflected radiation is the incident radiation (beam and diffuse) that has been reflected by
the earth. The sum of beams, diffuse and reflected radiation is considered as the global radiation
on a surface. As the majority of the energy is in the direct beam, maximizing collection requires
the sun to be visible to the panels as long as possible.
Declination Angle:
The fig.3.1 shows diagram of Declination Angle. The declination of the sun is the angle
between the equator and a line drawn from the centre of the Earth to the centre of the sun. The
declination is maximum (23.450) on the summer/winter (in India 21 June and 22 December)
The declination angle, denoted by d, varies seasonally due to the tilt of the Earth on its axis
of rotation and the rotation of the Earth around the sun. If the Earth were not tilted on its axis
7

16. Sun Tracking Solar System
Figure 3.1: The Declination Angles.[2]
of rotation, the declination would always be 0. However, the Earth is tilted by 23.45 and the
declination angle varies plus or minus this amount. Only at the spring and fall equinoxes is the
declination angle equal to 0.
Hour Angle:
The Hour Angle is the angular distance that the earth has rotated in a day. It is equal to 15
degrees multiplied by the number of hours from local solar noon. This is based on the nominal
time, 24 hours, required for the earth to rotate once i.e. 360 degrees. Solar hour angle is zero
when sun is straight over head, negative before noon, and positive after noon.(here noon means
12.00 hour)
Solar Altitude
The solar altitude is the vertical angle between the horizontal and the line connecting to the
sun. At sunset/sunrise altitude is 0 and is 90 degrees when the sun is at the zenith. The altitude
relates to the latitude of the site, the declination angle and the hour angle. Solar Azimuth
The azimuth angle is the angle within the horizontal plane measured from true South or
North. The azimuth angle is measured clockwise from the zero azimuth. For example, if
you’re in the Northern Hemisphere and the zero azimuth is set to South, the azimuth angle
value will be negative before solar noon, and positive after solar noon.
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17. Sun Tracking Solar System
Figure 3.2: Solar altitudes and azimuths typical behavior of sun path.[2]
Ramrao Adik Institute of Technology 9

18. Chapter 4
Functional Block Diagram
The main components of the above block diagram are as follows:
• solar panel
• LDRs
• DC Servomotors
• Arduino
Solar panel consists of photovoltaic cells arranged in an order. Photovoltaic cell is nothing
but a solar cell. When a light ray from Sun is incident on the solar cell, some amount of
energy is absorbed by this material. The absorbed energy is enough for the electrons to jump
from one orbit to other inside the atom. Cells have one or more electric field that directs the
electrons which creates current. The solar panel is positioned in such a way that the sun rays
are perpendicular to it.
10

19. Sun Tracking Solar System
Figure 4.1: Block diagram of Sun Tracking Solar Panel.[2]
The electrical system consists of five LDR sensors which provide feedback to a Arduino.
The Arduino processes the sensor input and provides two PWM signals for the movement of
servo motors. This servo motor moves the solar panel towards the higher density of solar light.
The entire electrical system is powered by a 12volt source power supply.
Sensors:
The high intensity of the sun rays can be sensed using sensors called LDRs (light dependent
resistors).Light Dependent Resistors are the resistors whose resistance values depend on in-
tensity of the light. As the intensity of light falling on the LDR increases, resistance value
decreases. In dark, LDR will have maximum resistance.. We are using Five Light Dependent
Resistors as a sensor. They sense the higher density area of sun light. The solar panel moves
to the high light density area through servo motors. Each LDR is connected to power supply
forming a potential divider. Thus any change in light density is proportional to the change
in voltage across the LDRs. LDR is a passive transducer hence we will use potential divider
circuit to obtain corresponding voltage value from the resistance of LDR. LDRs resistance is
inversely proportional to the intensity of light falling on it i.e. Higher the intensity or brightness
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20. Sun Tracking Solar System
of light the Lower the resistance and vice versa.
Arduino input:
Arduino has an inbuilt 10-bit Analog to Digital converter (ADC), hence it can provide Digital
values from 0-1023. We can also set the ADC reference voltage in arduino, but here well let it
use default value. LDRs has two pins, and to get voltage value from it we use potential divider
circuit. In potential divider we get Vout corresponding to resistance of LDR which in turn is
a function of light falling on LDR. The higher the intensity of light, lower the LDR resistance
and hence lower the Output voltage (Vout) And lower the light intensity, higher the LDR resis-
tance and hence higher the Vout. Arduino has a 8-bit PWM generator, so we can get up to 256
distinct.
DC Servomotor:
As it is a dual axis tracker we require two servomotor to rotate the tracker in both horizontal
and vertical directions. To drive a servo we need to get a PWM signal from the board, this
is usually accomplished using timer function of the microcontroller but arduino makes it very
easy. Arduino provides a servo library in which we have to only assign servo angle (0-180
degree) and the servo rotates by that angle, all the PWM calculations are handled by the servo
library and we get a neat PWM signal according to the desired angle.
Ramrao Adik Institute of Technology 12

21. Chapter 5
Design Methodology
5.1 Hardware
5.1.1 Solar panel
Figure 5.1: Solar Panel.[2]
Solar panel refers to a panel designed to absorb the sun’s rays as a source of energy for gen-
erating electricity or heating. A photovoltaic (in short PV) module is a packaged, connected
13

22. Sun Tracking Solar System
assembly of typically 610 solar cells. Solar Photovoltaic panels constitute the solar array of a
photovoltaic system that generates and supplies solar electricity in commercial and residential
applications. Each module is rated by its DC output power under standard test conditions, and
typically ranges from 100 to 365 watts. The efficiency of a module determines the area of a
module given the same rated output an 8 efficient 230 watt module will have twice the area
of a 16 efficient 230 watt module. There are a few solar panels available that are exceeding 19
efficiency. A single solar module can produce only a limited amount of power; most installa-
tions contain multiple modules. A photovoltaic system typically includes a panel or an array
of solar modules, a solar inverter, and sometimes a battery and/or solar tracker and intercon-
nection wiring. Solar modules use light energy (photons) from the sun to generate electricity
through the photovoltaic effect. The majority of modules use wafer-based crystalline silicon
cells or thin-film cells based on cadmium telluride or silicon. The structural (load carrying)
member of a module can either be the top layer or the back layer. Cells must also be protected
from mechanical damage and moisture. Most solar modules are rigid, but semi-flexible ones
are available, based on thin-film cells. These early solar modules were first used in space in
1958.
Electrical connections are made in series to achieve a desired output voltage and/or in
parallel to provide a desired current capability. The conducting wires that take the current
off the modules may contain silver, copper or other non-magnetic conductive transition metals.
The cells must be connected electrically to one another and to the rest of the system. Externally,
popular terrestrial usage photovoltaic modules use MC3 (older) or MC4 connectors to facilitate
easy weatherproof connections to the rest of the system.
Bypass diodes may be incorporated or used externally, in case of partial module shading,
to maximize the output of module sections still illuminated.
Some recent solar module designs include concentrators in which light is focused by lenses
or mirrors onto an array of smaller cells. This enables the use of cells with a high cost per unit
area (such as gallium arsenide) in a cost-effective way.
There are two types of trackers 1. Active Tracking System 2. Passive tracking System
Further the Active Tracking System is divided into:
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23. Sun Tracking Solar System
1.Single Axis Tracker
The sun travels through 360 degrees east-west a day, but from the perspective of any fixed
location the visible portion is 180 degrees during a 1/2 day period. 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 on either
side, and thus, according to the table above, will lose 75 percent of the energy in the morning
and evening. Rotating the panels to the east and west can help recapture these losses. A tracker
rotating in the east-west direction is known as a single-axis tracker.
2. Dual Axis Tracker
Figure 5.2: Dual Axis tracker [2]
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24. Sun Tracking Solar System
The sun also moves through 46 degrees north-south over the period of a year. The same
set of panels set at the midpoint between the two local extremes will thus see the sun move 23
degrees on either side, causing losses of 8.3 percent. A tracker that accounts for both the daily
and seasonal motions is known as a dual-axis tracker.
5.1.2 Sensors
A sensor is a device that measures a physical quantity and converts it into a signal which can be
read by an observer or by an instrument. 1. Light Dependent Resistor Light Dependent Resis-
tor is made of a high-resistance semiconductor. It can also be referred to as a photoconductor.
If light falling on the device is of the high enough frequency, photons absorbed by the semi-
conductor give bound electrons enough energy to jump into the conduction band. The resulting
free electron conducts electricity, thereby lowering resistance. Hence, Light Dependent Resis-
tors is very useful in light sensor circuits. LDR is very high-resistance, sometimes as high as
10MO, when they are illuminated with light resistance drops dramatically. A Light Dependent
Resistor is a resistor that changes in value according to the light falling on it. A commonly
used device, the ORP-12, has a high resistance in the dark, and a low resistance in the light.
Connecting the LDR to the Arduino is very straight forward, but some software calibrating is
required. It should be remembered that the LDR response is not linear, and so the readings
will not change in exactly the same way as with a potentiometer. In general there is a larger
resistance change at brighter light levels. This can be compensated for in the software by using
a smaller range at darker light levels.[8] 2. Photodiode// Photodiode is a light sensor which has
a high speed and high sensitive silicon PIN photodiode in a miniature flat plastic package. A
photodiode is designed to be responsive to optical input. Due to its water clear epoxy the device
is sensitive to visible and infrared radiation. The large active area combined with a flat case
gives a high sensitivity at a wide viewing angle. Photodiodes can be used in either zero bias
or reverse bias. In zero bias, light falling on the diode causes a voltage to develop across the
device, leading to a current in the forward bias direction. This is called the photovoltaic effect,
and is the basis for solar cells - in fact a solar cell is just a large number of big, cheap photo-
diodes. Diodes usually have extremely high resistance when reverse biased. This resistance is
reduced when light of an appropriate frequency shines on the junction. Hence, a reverse biased
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25. Sun Tracking Solar System
Figure 5.3: Light Dependent Resistor (LDR).[2]
diode can be used as a detector by monitoring the current running through it. Circuits based on
this effect are more sensitive to light than ones based on the photovoltaic effect.
5.1.3 DC Servo Motor
By itself the standard DC motor is not an acceptable method of controlling a sun tracking
array. This is due to the fact that DC motors are free spinning and subsequently difficult to
position accurately. Even if the timing for starting and stopping the motor is correctly achieved,
the armature does not stop immediately. DC motors have a very gradual acceleration and
deceleration curves, therefore stabilization is slow. Adding gearing to the motor will help
to reduce this problem, but overshoot is still present and will throw off the anticipated stop
position. The only way to effectively use a DC motor for precise positioning is to use a servo
.The servomotor is actually an assembly of four things: a normal DC motor, a gear reduction
unit, a position-sensing device (usually a potentiometer), and a control circuit. The function
of the servo is to receive a control signal that represents a 29 desired output position of the
servo shaft, and apply power to its DC motor until its shaft turns to that position. It uses the
position-sensing device to determine the rotational position of the shaft, so it knows which way
the motor must turn to move the shaft to the command position. The solar panel that attached
to the motor will be reacted according to the direction of the motor.[9]
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26. Sun Tracking Solar System
Figure 5.4: Schematic diagram of dc servo motor
Figure 5.5: DC Servo Motor.[2]
Specification
Rpm : 300 at 12v DC supply: 3 to 12V Metal Gears based Gearbox Output shaft: Centre
Torque : 2 Kg-cm Shaft diameter: 6 mm. Shaft length: 22 mm. Total length: 76 mm. Motor
diameter: 38 mm. Mounting Nut Width: 8mm Same size motor available in various rpm Hole
with threading (internal) in shaft for fixing wheel No-load current = 60 mA, Load current =
300 mA
5.1.4 Arduino Uno
Analog Reference pin (orange) Digital Ground (light green) Digital Pins 2-13 (green) Digital
Pins 0-1/Serial In/Out - TX/RX (dark green) - These pins cannot be used for digital i/o (digi-
talRead and digitalWrite) if you are also using serial communication (e.g. Serial.begin). Reset
Button - S1 (dark blue) In-circuit Serial Programmer (blue-green) Analog In Pins 0-5 (light
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27. Sun Tracking Solar System
Figure 5.6: Arduino Uno on board component.[2]
blue) Power and Ground Pins (power: orange, grounds: light orange) External Power Supply
In (9-12VDC) - X1 (pink) Toggles External Power and USB Power (place jumper on two pins
closest to desired supply) - SV1 (purple) USB (used for uploading sketches to the board and
for serial communication between the board and the computer; can be used to power the board)
(yellow) Digital Pins
In addition to the specific functions listed below, the digital pins on an Arduino board can be
used for general purpose input and output via the pinMode(), digitalRead(), and digitalWrite()
commands. Each pin has an internal pull-up resistor which can be turned on and off using
digitalWrite() (w/ a value of HIGH or LOW, respectively) when the pin is configured as an
input. The maximum current per pin is 40 mA.
Serial: 0 (RX) and 1 (TX). Used to receive (RX) and transmit (TX) TTL serial data. On
the Arduino Diecimila, these pins are connected to the corresponding pins of the FTDI USB-
to-TTL Serial chip. On the Arduino BT, they are connected to the corresponding pins of the
WT11 Bluetooth module. On the Arduino Mini and LilyPad Arduino, they are intended for
use with an external TTL serial module (e.g. the Mini-USB Adapter). External Interrupts: 2
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28. Sun Tracking Solar System
and 3. These pins can be configured to trigger an interrupt on a low value, a rising or falling
edge, or a change in value. See the attachInterrupt() function for details. PWM: 3, 5, 6, 9,
10, and 11. Provide 8-bit PWM output with the analogWrite() function. On boards with an
ATmega8, PWM output is available only on pins 9, 10, and 11. BT Reset: 7. (Arduino BT-only)
Connected to the reset line of the bluetooth module. SPI: 10 (SS), 11 (MOSI), 12 (MISO), 13
(SCK). These pins support SPI communication, which, although provided by the underlying
hardware, is not currently included in the Arduino language. LED: 13. On the Diecimila and
LilyPad, there is a built-in LED connected to digital pin 13. When the pin is HIGH value, the
LED is on, when the pin is LOW, it’s off. Analog Pins
In addition to the specific functions listed below, the analog input pins support 10-bit
analog-to-digital conversion (ADC) using the analogRead() function. Most of the analog in-
puts can also be used as digital pins: analog input 0 as digital pin 14 through analog input 5 as
digital pin 19. Analog inputs 6 and 7 (present on the Mini and BT) cannot be used as digital
pins.
I2C: 4 (SDA) and 5 (SCL). Support I2C (TWI) communication using the Wire library
(documentation on the Wiring website). Power Pins
VIN (sometimes labelled ”9V”). The input voltage to the Arduino board when it’s using an
external power source (as opposed to 5 volts from the USB connection or other regulated power
source). You can supply voltage through this pin, or, if supplying voltage via the power jack,
access it through this pin. Note that different boards accept different input voltages ranges,
please see the documentation for your board. Also note that the LilyPad has no VIN pin and
accepts only a regulated input. 5V. The regulated power supply used to power the microcon-
troller and other components on the board. This can come either from VIN via an on-board
regulator, or be supplied by USB or another regulated 5V supply. 3V3. (Diecimila-only) A 3.3
volt supply generated by the on-board FTDI chip. GND. Ground pins. Other Pins
AREF. Reference voltage for the analog inputs. Used with analogReference(). Reset.
(Diecimila-only) Bring this line LOW to reset the microcontroller. Typically used to add a
reset button to shields which block the one on the board.[10]
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29. Sun Tracking Solar System
5.2 Software
5.2.1 Arduino Software (IDE)
Figure 5.7: Arduino Software logo
The Arduino Integrated Development Environment - or Arduino Software (IDE) - contains
a text editor for writing code, a message area, a text console, a toolbar with buttons for common
functions and a series of menus. It connects to the Arduino and Genuino hardware to upload
programs and communicate with them.Programs written using Arduino Software (IDE) are
called sketches. These sketches are written in the text editor and are saved with the file ex-
tension .ino. The editor has features for cutting/pasting and for searching/replacing text. The
message area gives feedback while saving and exporting and also displays errors. The console
displays text output by the Arduino Software (IDE), including complete error messages and
other information. The bottom righthand corner of the window displays the configured board
and serial port. The toolbar buttons allow you to verify and upload programs, create, open, and
save sketches, and open the serial monitor.
ARDUINO 1.6.5
The open-source Arduino Software (IDE) makes it easy to write code and upload it to the
board. It runs on Windows, Mac OS X, and Linux. The environment is written in Java and
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30. Sun Tracking Solar System
based on Processing and other open-source software.
Advantage of solar tracker:
• Solar tracking systems continually orient photovoltaic panels towards the sun and can
help maximize your investment in your PV system.
• One time investment, which provides higher efficiency and flexibility on dependency
over other sources.
• Tracking systems can help reducing emissions and can contribute against global warm-
ing.
• Bulk implementations of tracking systems help reduced consumption of power by other
sources.
• Tracking systems can help reducing emissions and can contribute against global warm-
ing.
• It enhances the clean and emission free power production.
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31. Sun Tracking Solar System
Application of solar tracker:
• These panels can be used to power the traffic lights and street lights.
• These can be used in home to power the appliances using solar power.
• These can be used in industries as more energy can be saved by rotating the panel.
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32. Chapter 6
Work Plan
Activities done in Semester 7 (July to October):
• July to August:
Survey work and discussions with the allotted guide about the topic on which the project
is to be done and finalising the project topic as Sun Tracking Solar Panel.
• August to September:
Prepared the functional block diagram and the list of the major components required.
• September to October:
Studied the detailed operation of the components and their availability
Activities to be done in semester 8:
• Interfacing LDR sensor and DC Servomotor with Arduino Uno.
• Designing and implementation of hardware model.
• For further advancement,interfacing LCD with Arduino for displaying the output voltage
of the solar panel.
• On the basis of the output voltage,the application and storage devices would be decided.
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33. Chapter 7
Conclusion
A modeling and optimization method from a new point of view is proposed. More factors can
be taken into consideration in the future modeling and optimization, such as the sensitivity
range of the controlling system which determines when the solar tracker should operate to
generate more power or stay still to save energy. The research provides references for solar
tracking system designing, and the modeling and optimization method can be modified and
applied in other mechanical and electronic systems.
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34. Bibliography
[1] Rizk J., Engineering Chaiko Y. Solar Tracking System: More Efficient Use of Solar Pan-
els, World Academy of Science, and Technology 41 2008.
[2] image.google.com.
[3] ”Solar Tracker Robot using Microcontroller”. A.B. Afarulrazi, W. M. Utomo, K.L. Liew
and M. Zarafi.
[4] Design, Rifat Rahman S M Shafiul Alam published in 6th International Conference
on Electrical Construction of an Automatic Solar Tracking System by Md. Tanvir
Arafat Khan, S.M. Shahrear Tanzil, and 18-20 December 2010 Computer Engineering
ICECE 2010.
[5] ”IMPLEMENTATION OF A PROTOTYPE FOR A TRADITIONAL SOLAR TRACK-
ING SYSTEM” by Nader Barsoum published in the 2009”.
[6] Arduino Based Solar Tracking System” by Aleksandar Stjepanovic.
[7] Microcontroller-Based Two-Axis Solar Tracking System” by Lwin Lwin Oo and
Nang Kaythi Hlaing.
[8] A Novel Low Cost Automatic Solar Tracking System Microcontroller-Based Two-Axis
Solar Tracking System” by Lwin Lwin Oo and Nang Kaythi Hlaing.
[9] Design and Construction of an Automatic Solar Tracking System. by Tanvir Arafat Khan
Md., S.M. ShahrearTanzil, RifatRahman, S M ShafiulAlam, System,presented at 6th In-
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35. Sun Tracking Solar System
ternational Conference on Electrical and Computer EngineeringICECE 2010, 18-20 De-
cember 2010, Dhaka, Bangladesh.
[10] Cha J.Z. Liu W. Guo, Y.Z. and Y.B. A System Modeling Method for Optimization of a
Single Axis Solar Tracker. ICCASM 2010. Tian.
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