ASSOSA UNIVERSITY

COLLEGE OF ENGINEERING

DEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERING

TITLE:SINGLE AXIS SOLAR POWER TRACKING SYSTEM

NAME ID

1 ANDUALEM GENETU...............................................2983/13
2 EYASU BAZEZEW......................................................0721/13
3 NEGA ASFAW.............................................................2872/13
4 PAL GATLUAK...........................................................2881/13
5 YOHANNIS MEQUANNET .......................................1969/13

SUBMITED TO: MRS. BETELHAM

SUBMISSION DATE:5/6/2016

ASSOSA , ETHIOPIA
 Declaration

This is certify that we, group one student's of electrical and computer engineering at
Assosa University have submitted this research proposal on the topic of single axis
solar power tracking system.
Moreover we certify that this entire research material are belonging to us bachelor
degree in electrical and computer engineering dissertation which we now submitted for
assessment purpose.Finally we declare it has not been submitted in part or in whole to
any other college or university for assessment or for award of any other academic degree.

i
 Signature Page

Student's Name Signature

1 Andualem Genetu 

2 Eyasu Bazezew 

3 Nega Asfaw 

4 Pal Gatluak 

5 Yohannis Mequannet 

ii
 Abstract

The aim of this research is to consume the maximum solar energy through solar panel.
A Solar Tracker is a device onto which solar panels are built-in which tracks the motion
of the sun ensuring that maximum amount of sunlight strikes the panels all over the day.
Power output from a solar cell will be maximum when it is facing the sun i.e. the angle
between its surface and sun rays is 90 degree. Solar tracking allows more energy to be
produced because the solar array is able to remain aligned to the sun. The components
used for its construction are servo motor, Arduino and LDR. The active sensors
continuously monitor the sunlight and alternate the panel towards the direction where
the intensity of sunlight is maximum. In this project, it's divided by two categories;
hardware and software. In hardware part, 2 light dependent resistor (LDR) has been
used to trace the synchroniz of sunlight by detecting brightness level of sunlight. For
rotation part, one standard servo motor has been selected. In software part, the code is
constructed in C programming and inserted in Arduino. This project is designed for low
power and portable application. Therefore, it's suitable for rural area usage. Moreover,
the eectiveness of output power which collected by sunlight are increased.

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 Acknowledgment

First, we express our heartiest thanks and gratefulness to almighty God for his divine
blessing makes us possible to complete this research successfully.
We would also like to express our gratitude to our teacher Mrs.Beteleham for her
consistent help with supporting ideas and advises on this project. She is also assisting
us in answering our unclear questions beside of our capacity continuously throughout
the research and giving us an advice.

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Contents

1 Chapter 1
Introduction 1
1.1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Statement Of The Problem . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 Objective of the project . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3.1 General objective . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3.2 Specic Objective . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.4 Signicance of the project . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.5 Scope of Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2 Chapter 2
literature Review 4

3 Chapter 3
Methodology 6
3.1 Materials required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.2 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.3 Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.4 Working Principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

4 Chapter 4
Result And Discussion 12
4.1 Simulation and Result . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

5 Chapter 5
conclusion 15
5.1 Recommendation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

v
List of Figures

3.1 photo-voltaic-cell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.2 Functional block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.3 working principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

4.1 Middy position of LDR or right LDR = left LDR . . . . . . . . . . . . . 12

4.2 When right LDR the lighter intensity detects the motor turn east . . . . 13
4.3 when the left LDR is more light intensity detect. . . . . . . . . . . . . . . 14

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List Of Acronyms

AC Alternate-Current
CDS Cadmium-Sulde
DC Direct-Current
HSAT Horizontal-Single-Axis-Tracker
HTSAT Horizontal-Single-Axis-Tracker with-Tilted-Module
LCD Liquid-Crystal-Display
LDR Light-Dependent-Resister
PASAT Polar-Aligned-Single-Axis-Tracker
PV Photo-Voltaic
PW Peak-Watt
PWM Pulse-Width-Modulation
TACS Tracking and Control System
VSAT Vertical-Single-Axis-Tracker

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Chapter 1
Introduction

1.1 Background
The increasing demand for energy, the continuous reduction in existing sources of fossil
fuels and the growing concern regarding environment pollution, have pushed mankind to
explore new technologies for the production of electrical energy using clean, renewable
sources, such as solar energy, wind energy, etc. Among the non-conventional, renewable
energy sources, solar energy aords great potential for conversion into electric power,able
to ensure an important part of the electrical energy needs of the planet.
The conversion of solar light into electrical energy represents one of the most promising
and challenging energetic technologies, in continuous development, being clean, silent and
reliable, with very low maintenance costs and minimal ecological impact.[1]
Solar energy is free, practically inexhaustible, and involves no polluting residues or green-
house gases emissions. The conversion principle of solar light into electricity, called Photo-
Voltaic or PV conversion, is not very new, but the eciency improvement of the PV
conversion equipment is still one of top priorities for many academic and/or industrial
research groups all over the world. Among the proposed solutions for improving the ef-
ciency of PV conversion, we can mention solar tracking the optimization of solar cell
conguration and geometry new materials and technologies etc.
Maximizing power output from a solar system is desirable to increase eciency. In order
to maximize power output from the solar panels, one needs to keep the panels aligned
with the sun. As such, a means of tracking the sun is required. This is a far more cost
eective solution than purchasing additional solar panels. It has been estimated that
the yield from solar panels can be increased by 30 to 60 percent by utilizing a tracking
system instead of a stationary array. This project develops an automatic tracking system
which will keep the solar panels aligned with the sun in order to maximize eciency.This
paper begins with presenting background theory in light sensors and servo motor as they
applied to the project. The paper continues with specic design methodologies pertaining
to photocells, servo motors and drivers. Compared to a xed panel, a mobile PV panel
driven by a solar tracker is kept under the best possible insulation for all positions of the
Sun, as the light falls close to the geometric normal incidence angle.

1
1.2 Statement Of The Problem
As we can see, there are many problems that occur in the eective use of solar energy
due to dierent conditions of the sun and other environmental factor.
The problem that we can see here is the solar panel that has no any tracking of sun
directions. Because of this problem, the power that can be generated is low.
The second problem is the price for the solar tracking system is very expensive for the
user that use more power than usual because they need to install more than one solar
panel to produce enough power.
This project is to x the problem that occurs here. The solar panel that can be generating
here is very high compare to when the solar panel can only stay in one direction. So, the
families don't have to install more than one solar panel to generate enough power. In
remote areas the sun is a cheap source of electricity because instead of hydraulic generators
it uses solar cells to produce electricity. While the output of solar cells depends on the
intensity of sunlight and the angle of incidence, it means to get maximum eciency; the
solar panels must remain in front of sun during the whole day. But due to rotation of earth
those panels can't maintain their position always in front of sun. This problem results
in decrease of their eciency. Thus, to get a constant output, an automated system is
required which should be capable to constantly rotate the solar panel to receive maximum
solar energy. The Solar Radiation Tracking System is one of the proven methods to get
around this problem.

1.3 Objective of the project

1.3.1 General objective
◦ To design a system that can detect and compare the intensity of light and able to
move a servo motor based on the intensity of light

1.3.2 Specic Objective

◦ Interfacing of light dependent resistor, servo motor on Arduino

◦ Programming or coding for proper working of the LDR and motor

◦ Maximize output energy production

◦ Decreases ower cost

◦ comparing the xed solar power system and single axis solar power tracking system

1.4 Signicance of the project

This project has many signicance this are

◦ It increases energy by tracking sun direction it properly converts sun radiation into
energy

◦ It maximize output energy produced by the PV panel, through an Optimal posi-

tioning executed only for sucient values of light signal Intensity;

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 ◦ It decreases the cost of the owner because it decreases of buying addition solar panel
if he is using solar tracker, it can properly use sun radiation and he can get ecient
energy.

1.5 Scope of Project

The scope of this project is to develop continuous real time condition monitoring and
control system for solar tracking based on the intensity of light .so, the project is goon
up to simulation.

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Chapter 2
Literature Review

Solar tracking system project had been widely employed by the other giant company
like BP Solar, Yingli Green Energy, Kyocera, Q-Cells, Sanyo, Sharp Solar, Solar World,
Sun Power, and Sundeck. Now, many people use solar energy or photovoltaic energy as
an alternative power because it's free and renewable. As we can see now, the payment
charge for an electricity had been risen rapidly because the increasing of gas price. Many
researchers have tried to nd the alternative energy to replace the gas [2, 3].
A real-time prole of the TACS activity was produced and the data analysis showed a
deviation in maximum power of less than 1% during the day after accounting for other
variations [2, 4]. Proposed a 150W solar tracking system in 2003.
One of the alternative energy's that we can use is photovoltaic energy. Photovoltaic
energy is the most promising and popular form of solar energy. In solar photovoltaics,
sunlight is actually converted into electricity. This is very dierent from a conventional
understanding of solar power as only a way of heating water. Photovoltaic, now the
biggest usage of solar energy around the world, is briey explained below: Sunlight is
made of photons, small particles of energy [4]. These photons are absorbed by and pass
through the material of a solar cell or solar photovoltaic panel.
The photons 'agitate' the electrons found in the material of the photovoltaic cell. As
they begin to move (or are dislodged), these are 'routed' into a current. This, technically,
is electricity - the movement of electrons along a path. Solar panels made of silicon to
convert sunlight into electricity [5]. Solar photovoltaic are used in a number of ways,
primarily to power homes that are inter-tied or interconnected with the grid. Wire
conducts these electrons, either to batteries or to the regular electrical system of the
house, to be used by appliances and other household electrical items.
In many solar energy systems, the battery stores energy for later use. This is especially
true when the sun is shining strongly. It was capable of maintaining the peak power
position of a photovoltaic (PV) array by adjusting the load on the array for maximum
eciency and changed the position of the array relative to the sun. At large PV array
system installations, inverters were used to convert the dc electrical output to ac for power
grid compatibility. Adjustment of the inverter or load for maximum array output was
one function performed by the tracking and control system. Another important function
of the system was the tracking of the sun, often a necessity for concentrating arrays.
The TACS also minimized several other problems associated with conventional shadow
band sun trackers such as their susceptibility to dust and dirt that might cause drift in

4
solar alignment. It also minimized eects of structural war page or sag to which large
arrays might be subjected during the day. Array positioning was controlled by Q single-
board computer used with a specially designed input output board. An orderly method
of stepped movements and the nding of new peak power points were implemented.
This maximum power positioning concept was tested using a small two-axis tracking
concentrator array.In solar tracking system, they used DC motors, special motors like
stepper motors, servo motor sand real-time actuators, to operate moving parts. DC
motors were normally used to operate solar tracking system but it was highly expensive
to maintain and repair.

5
Chapter 3
Methodology

3.1 Materials required

I. Hardware Components
A. Light Sensors
LDRs or Light Dependent Resistors are very useful especially in light/dark sensor cir-
cuits.Normally the resistance of an LDR is very high, sometimes as high as 1,000,000
ohms, but when they are illuminated with light, resistance drops dramatically. When
the light level of LDR1 is low the resistance of the LDR1 is high and when light level of
LDR2 is high, the resistance of LDR2 is low. the region of the p-type material near the
junction takes on a net negative charge because of the electrons attracted. Since electrons
departed the N-type region, it takes on a localized positive charge.
The thin layer of the crystal lattice between these charges has been depleted of majority
carriers, thus, is known as the depletion region. It becomes non conductive intrinsic semi-
conductor material. This separation of charges at the p-n junction constitutes a potential
barrier, which must be overcome by an external voltage source to make the junction con-
duct. The electric eld created by the space charge region opposes the diusion process
for both electrons and holes. A Light Dependent Resistor (LDR) is also called a photo
resistor or a cadmium sulde (CDS) cell. It is also called a photo conductor. It is basically
a photocell that works on the principle of photo conductivity. The passive component is
basically a resistor whose resistance value decreases when the intensity of light decreases.
This photo electronic device is mostly used in light varying sensor circuit, and light and
dark activated switching circuits. Some of its applications include camera light meters,
street lights.

B. Photovoltaic
Photovoltaic (PV) is a technology that converts light directly into electricity. Photo
voltaic is also the eld of study relating to this technology and there are many research
institutes devoted to work on photovoltaic. Due to the growing need for solar energy,
the manufacture of solar cells and solar photovoltaic array has expanded dramatically
since2002.making it the world's fastest growing energy technology. The photovoltaic cell
is the basic building block of a photovoltaic system. Individual cells can vary in size from

6
about 0.5 inches to about 4 inches across. However, one cell only produces 1or 2 watts,
which isn't enough power for most applications. The performance of a photovoltaic array
is dependent upon the sunlight. Climatic conditions (e.g. clouds, fog) have a signicant
eect on the amount of solar energy received by a photovoltaic array and, in turn, its
performance.[6]

Figure 3.1: photo-voltaic-cell

C. Microcontroler
Microcontroller is a single IC containing specialized circuits and functions that are appli-
cable to smechatronic system design. It contains a microprocessor, memory, I/O capa-
bilities, and other on chip resources. It is basically a microcomputer on a single IC.

D. Servo Motor
Servo motors have been around for a long time and are used in many applications. They
are small in size but pack a big punch and are very energy ecient. Because of these
features, they can be used to operate remote-controlled or radio-controlled toy cars,
robots and airplanes. Servo motors are also used in industrial applications, robotics,
in-line manufacturing, pharmaceutics and food services. Servos are controlled by sending
an electrical pulse of variable width, or pulse width modulation (PWM), through the
control wire. There is a minimum pulse, a maximum pulse and a repetition rate. A servo
motor can usually only turn 90° in either direction for a total of 180° movement. The
motor's neutral position is dened as the position where the servo has the same amount
of potential rotation in the both the clockwise or counterclockwise direction. The PWM
sent to the motor determines position of the shaft, and based on the duration of the
pulse sent via the control wire the rotor will turn to the desired position. The servo
motor expects to see a pulse every 20 milliseconds (MS) and the length of the pulse will
determine how far the motor turns. For example, a 1.5ms pulse will make the motor turn
to the 90° position. Shorter than 1.5ms moves it to 0° and any longer than 1.5ms will
turn the servo to 180°. When these servos are commanded to move, they will move to the
position and hold that position. If an external force pushes against the servo while the
servo is holding a position, the servo will resist from moving out of that position. The
maximum amount of force the servo can exert is called the torque rating of the servo.

7
Servos will not hold their position forever though; the position pulse must be repeated
to instruct the servo to stay in position.

E. LCD (Liquid Crystal Display)

A liquid-crystal display (LCD) is a at panel display, electronic visual display, or video
display that uses the light modulating properties of liquid crystals. Liquid crystals do
not emit light directly.

II. Software Components

◦ Arduino IDE

◦ Proteus 8 professional (for simulation)

3.2 Block Diagram

Figure 3.2: Functional block diagram

8
3.3 Methodology
◦ A technique used in the design and principles operation of a solar tracking system
will help us to demonstrate the general principles operation of solar tracking system.
Firstly,the two sensors detect the solar radiation; if one of the two sensor gets more
amount of radiation, the servo motor rotates the PV panel until the two sensors
get equal amount of radiation; then after the two sensors get the same amount of
radiation, the servo motor stays in its position until the two sensors get unbalanced
radiation. As the sun continues to move from east to west, simultaneously the servo
motor starts to rotate the PV panel anticlockwise direction to balance the amount
of radiation falling on to the sensors.

◦ The amount of radiation falling on to the sensor balancing process continues through-
out the day. The main impulsion is to design a high-quality solar tracker. This
paper is divided into two parts; hardware and software. It consists of three main
constituent which are the inputs, controller and the output as shown in Fig B photo
resistor or Light dependent resistor (LDR) or photocell is a light-controlled variable
resistor.

◦ LDRs or Light Dependent Resistors are very useful especially in light/dark sen-
sor circuits. Normally the resistance of an LDR is very high, sometimes as high
as 1000000 ohms, but when they are illuminated with light resistance drops dra-
matically. The Servo motor can turn either clockwise or anticlockwise direction
depending upon the sequence of the logic signals. The sequence of the logic signals
depends on the dierence of light intensity of the LDR sensors. The principle of
the solar tracking system is done by Light Dependent Resistor (LDR).

◦ Two LDR's are connected to Arduino analog pin AO to A1 that acts as the input
for the system. The built-in Analog-to-Digital Converter will convert the analog
value of LDR and convert it into digital. The inputs are from analog value of LDR,
Arduino as the controller and the Servo motor will be the output. LDR1 and LDR2
are taken as pair. If one of the LDR gets more light intensity than the other, a
dierence will occur on node voltages sent to the respective Arduino channel to
take necessary action. The Servo motor will move the solar panel to the position
of the high intensity LDR that was in the programming.

Single Axis Trackers

◦ Single axis trackers have one degree of freedom that acts as an axis of rotation.
The axis of rotation of single axis trackers is typically aligned along a true North
meridian. It is possible to align them in any cardinal direction with advanced
tracking algorithms. There are several common implementations of single axis
trackers. These include horizontal single axis trackers (HSAT), horizontal single
axis tracker with tilted modules (HTSAT), vertical single axis trackers (VSAT),
tilted single axis trackers (TSAT) and polar aligned single axis trackers (PSAT).
The orientation of the module with respect to the tracker axis is important when
modeling performance. Single axis tracker may be horizontal or vertical axis.

9
3.4 Working Principle
◦ When morning arrives, the left LDR1 is turned on (small resistance approximately
shorted), causing a signal to turn the motor continuously counterclockwise until the
two LDRs having the same light intensity again at position (b). As the day slowly
progresses position (C) or midday is reached, turning on the LDRs. The motor
turns clockwise, and the cycle continues until the end of the day at position (d)
or until the minimum detectable light level is reached. In this process the stable
position is when the two LDRs having the same light intensity at position (b), (c)
and (d); but position (a) is unstable position.Making design in proteus with some
steps

Figure 3.3: working principle

10
◦ Open ISIS software in the proteus then go to component mode and click P(pick
from library)

◦ write Arduino and select and click into the workspace and connect the required
components

11
Chapter 4
Result And Discussion

4.1 Simulation and Result

1.When morning arrives, the left LDR1 is turned on and the right LDR at equal posi-
tioning. At this position drive system or servo motor does not rotates at any direction.

Figure 4.1: Middy position of LDR or right LDR = left LDR

2.When morning arrives, the right LDR have more intensity of light than the left LDR,
the servo motor rotate clockwise 90degree in the east direction.

12
 Figure 4.2: When right LDR the lighter intensity detects the motor turn east

3.While the left LDR have more light intensity than right LDR, the servo motor
rotates anticlockwise 90 degree in the west direction.

13
Figure 4.3: when the left LDR is more light intensity detect.

14
Chapter 5
Conclusion

Based on the obtained results we can conclude that the proposed solution for a Solar
tracking system oers several advantages concerning the movement Command of the PV
panel:

◦ A minimum of energy consumption, due to the fact that the panel movement is
carried out only in justied cases, eliminating unnecessary consumption of energy,
and due to the cutting of the power circuits supply between the movement periods
of the PV panel;

◦ A maximization of output energy produced by the PV panel, through an optimal

positioning executed only for sucient values of light signal Intensity.

◦ A panel position starting from any initial position of the PV panel.

◦ It has been shown that the sun tracking systems can collect more energy than
what a xed panel system collects and thus high eciency is achieved through this
tracker. Increase in eciency is not the most signicant gure; it can be more
prominent in concentrating type reectors.

◦ Single axis solar power tracking system are much more ecient than xed solar
panels due to their ability to follow the sun. A single-axis tracking solar system
add 30 to 60% of increased energy to ower system.

5.1 Recommendation
If anyone who interested to work on automatic solar tracking project you can use this
project as an introduction and continue working on dual axis solar tracking systems, since
we can get better energy than single axis.

15
Reference
[1]https://www.academia.edu/53672970/Single_axis_solar_tracking_system:- for para-
grah 1intro
[2] P. A. Basore, "Manufacturing a New Poly crystalline Silicon PV Technology", IEEE
4thWorld Conference on Photovoltaic Energy Conversion, pp. 2089-2093, 2006.
[3] P. Turmezei, "Chalcogenide Materials for Solar Energy Conversion", Acta Poly tech-
nical Hungarica, Vol. 1, No. 2, pp. 13-16, 2004.
[4] [Aliman and Daut, 2007] Omar Aliman, Ismail Daut,Rotation-Elevation of Sun
Tracking Mode to Gain High Concentration Solar Energy, IEEE Conference, 12-14April
2007,Page(s):551  555
[5] [Armstrong and Hurley, 2005] S. Armstrong and W.G Hurley Investigating the Ef-
fectiveness of Maximum Power Point Tracking for a Solar System, IEEE Conference on
Power Electronics, 2005 Page(s):204  209.
[6] https:elegoo.com/sensorkit

16
Appendix
# include <Servo.h>
# include <LiquidCrystal.h>
LiquidCrystal lcd(12,11,5,4,3,2);
Servo vertical;
int servov = 180;
int servovLimitHigh = 180;// maximum rotation angle we can change
int servovLimitLow = 0;//minimum rotation angle
int ldrl = 0;
int ldrr = 1;
void setup()
{
Serial.begin(9600);
lcd.begin(16,2);
lcd.clear();
lcd.setCursor(0,0);
vertical.attach(10);
vertical.write(0);
delay(50);
}
void loop()
{
int l = analogRead(ldrl);
int r = analogRead(ldrr);
int dtime = 50;
if (l > r)
{
servov = ++servov;
if (servov < servovLimitHigh)
{
servov = servovLimitHigh;
}
vertical.write(servov);
lcd.setCursor(0,0);
lcd.print("East direction");
}
else if (l < r)
{
servov = servov;
if (servov > servovLimitLow)
{
servov = servovLimitLow;
}
vertical.write(servov);
lcd.setCursor(0,0);
lcd.print("West direction");
}

17
else
{
lcd.setCursor(0,0);
lcd.print("nothing ");
}
delay(50);
}

18