2013 IEEE International Conference on Control System, Computing and Engineering, 29 Nov. - 1 Dec.

2013, Penang, Malaysia

Performance Analysis of Dual-axis Solar

Tracking System
N.Othman M.I.A. Manan, Z. Othman, S.A.M. Al Junid
Faculty of Electrical Engineering Faculty of Electrical Engineering
Universiti Teknologi MARA (UiTM) Universiti Teknologi MARA (UiTM)
13500 Permatang Pauh, Pulau Pinang, Malaysia 40450 Shah Alam, Selangor.
e-mail: halida8142@ppinang.uitm.edu.my ikhsanmanan@yahoo.com,
zulkifli_othman@salam.uitm.edu.my,
samaljunid@salam.uitm.edu.my,

Abstract — This paper presents the performance analysis of dual- In the last ten years, many residential areas around the
axis solar tracking system using Arduino. The ultimate objective of world used electric solar system as a back-up power for their
this project is to investigate whether static solar panel is better houses. This was because solar energy, which is the energy
than solar tracker, or the opposite. This project is divided into two derived from the sun through the form of radiation, is also an
stages namely, hardware and software development. In hardware
unlimited energy resource and is going to become increasingly
development, five light dependent resistors (LDR) were utilized to
capture the maximum light source from the sun. Two servo motors important in the long term for providing light, heat and energy
also were employed to move the solar panel to maximum light to all living things [2]. It is also related to the aspects of
source location sensed by the LDRs. As for the software part, the deforestation control, protection of ozone layer, reduction of
code was constructed by using C programming language and was CO2 emission and so on [3]. In order to utilize the superiority
targeted to the Arduino UNO controller. The performance of the of solar energy, solar tracker was constructed for this project.
solar tracker was analyzed and compared with the static solar
panel and the result showed that the solar tracker is better than the Solar tracker is a device used to orient a solar panel
static solar panel in terms of voltage, current and power. towards the sun. Since the sun's position in the sky changes
Therefore, the solar tracker is proven more effective for capturing
with the time of day, solar tracker is used to track the maximum
the maximum sunlight source for solar harvesting applications.
amount of light produced by the sun. It is discovered that the
Keywords- Dual-axis, Solar Tracker, Arduino, Light Dependant instantaneous solar radiation collected by the photovoltaic
Resistor modules, assembled in a tracking system, is higher than the
critical irradiance level for longer hours than in fixed systems
I. INTRODUCTION [4]. Besides, it is estimated that the yield from solar panels can
be increased by 30 to 60 percent by utilizing a tracking system
Renewable-energy is energy which comes from natural instead of a stationary array [5]. Up to 40% extra power can be
resources such as sunlight, wind, rain, tides, and geothermal produced per annum using a variable elevation solar tracker
heat, which are renewable (naturally replenished) [1]. It [6]. Nowadays, there are many types of solar trackers invented
provides 19% of electricity generation worldwide. Malaysia, but the two basic categories of trackers that are widely-used are
with its population of about 28 million people, is one of the single-axis and dual-axis tracker. Single-axis tracker can either
fastest economically growing countries in Asia. In the last has a horizontal or a vertical axis, while dual-axis tracker have
decade, Malaysia managed to achieve almost 20% increase in both horizontal and vertical axis, thus making them able to
energy generation which was from 13,000MW in 2000 to track the sun's apparent motion almost anywhere in the world.
15,500MW in 2009. Under the 8th Malaysia’s plan (2001-
2005), the government of Malaysia changed the Four Fuel In this project, the performance of the dual-axis solar
Policy which was based on oil, gas, coal and hydropower to the tracker was analyzed. It was separated into three parts which
Five-Fuel Policy with the addition of renewable energy as the were input, controller and output. The input was from the
fifth element. The demands for electricity keep increasing year LDRs, the Arduino as the controller and, the servo motor as the
by year, but the main resources which are oil, gas and coal are output.
depleting. Solar energy, which is one of the types of renewable
energy, has been identified by the government as the best
initiative in order to solve this problem.

978-1-4799-1508-8/13/$31.00 ©2013 IEEE 370

 2013 IEEE International Conference on Control System, Computing and Engineering, 29 Nov. - 1 Dec. 2013, Penang, Malaysia

2) Servo Motor

Servo motor is one of the various types of DC motor

available in electronic application. This type of motor requires
supply either 4.8V or 6V. This motor consists of three wires
namely signal, positive and ground wire. It also comprises
several parts which are the motor and gearbox, position sensor,
an error amplifier, motor driver and a circuit to decode the
requested position. Servo motor only rotates by the maximum of
Figure 1. Single-axis and dual-axis solar tracker.
180 degrees. PWM is used to control the motor. PWM analog
signal will go through an electronic circuit and convert the
analog signal into a digital signal. PWM in servos is used to
II. METHODOLOGY control the direction and position of the motor. There were two
As stated before, the aim of this project is to analyze the servo motors used in this project for horizontal and vertical axis
performance of dual-axis solar tracking system. It consists of respectively.
three main structures which are the inputs, the controller and the
output. The inputs are from the LDRs, the Arduino as the
controller and, the servo motor as the output. The overall system
is presented in Figure 2. In this project, the main controller
which is the Arduino receives analog input from LDRs and it
converts the input into digital signal by using analog-to-digital
(A-D) converter. Then the controller sends the signal to the
servo motor in order to determine the movement of the solar
panel.

Figure 3. Servo motor

MAIN
CONTROLLER OUTPUT 3) Solar Panel
INPUT
(ARDUINO)
(LDR) (SERVO)
Solar panel, which is also called ‘photovoltaic’, is a device
that converts light directly into electricity. There are many types
of solar panel distinguished by their efficiency, price and
temperature coefficient that are available in the market. Some of
Figure 2. Block diagram of overall system them are monocrystalline, polycrystalline and thin film. The
monocrystalline type of solar panel was selected for this project
This project also can be divided into two parts which are
because it has the highest efficiency compared to other types.
hardware and software:

A. Hardware

The components involved in this part are solar panel, LDR,

servo motor and Arduino-Uno Controller.

1) Light Dependant Resistor (LDR)

Photoresistor or light dependant resistor (LDR) is a resistor

whose resistance decreases with increasing light intensity or it
can be said that the LDR exhibits photoconductivity. For this
project, the intensity of light sensed by the LDR becomes an
input to the main controller.
Figure 4. Model of solar panel

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 2013 IEEE International Conference on Control System, Computing and Engineering, 29 Nov. - 1 Dec. 2013, Penang, Malaysia

4) Programmer

Arduino is an open-source electronics prototyping platform

based on flexible and easy-to-use hardware and software.
Arduino can sense the environment by receiving input from a
variety of sensors that can affect its surroundings. Arduino
projects can be stand-alone, or they can communicate with
software running on a computer. In this development, Arduino
is used as the main controller for the project. There are many
types of Arduino boards but for this project, Arduino UNO was
selected. This is because it satisfies these conditions:

a) Microcontroller board based on the ATmega328.

b) 14 digital input/output pins (of which 6 can be used as
PWM outputs), 6 analog inputs, a 16 MHz crystal
oscillator, a USB connection, a power jack, an ICSP
header and a reset button.

Figure 5. Arduino-Uno board

B. Software
Figure 6. Flow chart of software
The software part consisted of a programming language
that was constructed by using C programming. The codes were
targeted to Arduino UNO board to be compiled and uploaded.
The flow of the software procedure is shown in Figure 6. The
five LDRs were connected to Arduino analog pin A0 to A4 to
act as the input for the system. The built-in Analog-to-Digital
Converter converted the analog value of LDR into digital PWM.
The values of PWM pulse then were applied (exploited?) to
move the servos. The maximum light intensity captured by one
of the LDR inputs was selected and later the servo motor would
move the solar panel to the position of the LDR that was set up
in the programming. There were three points of motor rotation;
0, 90 and 180 degrees. The positions of LDRs were divided into
five positions which were centre, right, left, up and down. These
five positions were the best positions that could detect the
highest intensity of sunlight.

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 2013 IEEE International Conference on Control System, Computing and Engineering, 29 Nov. - 1 Dec. 2013, Penang, Malaysia

III. RESULTS AND DISCUSSIONS

Figure 7 shows the graph of output voltage comparison
between static panel and panel witth tracking system for day 1.
The results revealed that the location of thee solar panel was As it can be seen in the graph, thee output voltage recorded for
one of the important things in collecting its ouutput voltage and solar panel with tracking system m is higher than the output
current. It was also discovered that solar panell would perform voltage of static solar panel at mo ost of the time. For the solar
the best when facing south as this would helpp to receive the tracker, the highest output voltaage recorded was 12.6V at
most exposure from the sun as it moved from eeast to west. For 1.00p.m while the lowest output vo oltage was 12.09V at 6.00p.m.
most locations, the peak performance hours oof the day were As for the static panel, the highest and the lowest output voltage
between 9a.m till 12p.m. This was when thee sun was at its recorded were 12.6V and 11.89V respectively. The cloud was
highest illumination. the main factor that contributed d to the instability in the
measurement of the output voltaage and this was due to its
The measurements of the data were taken ffrom a wide area presence that blocked the sun, causing the surrounding to be dim
where there was no obstruction that would preevent the tracker at certain times. As a consequencce, the solar panels were not
from getting the maximum sunlight. The measurrement of output able to obtain the maximum illumin nation from the sun.
voltages and currents were taken at two diffe ferent days from
9a.m until 6.00p.m. The data collected is dem monstrated in the
graphs below. It was a very sunny day for day 1, but it was quite
cloudy on day 2. There were two similar typess of solar panels
used which followed these conditions:

• Static solar panel with 10 degree of anggle facing south

• Solar panel with tracking system facingg south

These two conditions enabled the panelss to capture the

highest and lowest output voltages and curreents at the peak
performance of sunlight.

TABLE 1. SOLAR PANEL DATASHEE

ET

Model type: SBE15070

Maximum Power Current (Imp) 0.1AA
Maximum Power Voltage (Vmp) 12VV Figure 8. Output current comparison between
b static panel and tracker
Short-Circuit Current (Isc) 0.111A
Open-Circuit Voltage (Voc) 14.44V Figure 8 shows the graphs of output current
comparison between the static pan nel and the tracker for day 1.
Clearly as illustrated in the graph,, the output current recorded
A. Day 1 for solar panel with tracking systeem is higher than the output
current of static solar panel at moost of the times. However, at
certain points, the value of outp put current for both panels
recorded similar number. This occcurred because during these
points, the location of the sun was the
t same for both panels. The
same condition was also employ yed for the output voltage
measurement as presented in Figurre 7. For the solar tracker, the
highest output current recorded was 98.1mA at 1.00p.m while
the lowest output current was 9.5 5mA at 6.00p.m. As for the
static panel, the highest and the lo
owest output current recorded
were 98.1mA and 8.1mA respectively. As shown in Figure 7,
the cloud was also the main factorr that caused the instability in
the measurement of the output curreent.

Figure 7. Output voltage comparison between static paanel and tracker

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 2013 IEEE International Conference on Control System, Computing and Engineering, 29 Nov. - 1 Dec. 2013, Penang, Malaysia

6.00p.m. On the contrary, for the static panel, the highest and
the lowest output voltage recordeed were 12.58V and 11.87V
respectively. As shown in Figure 7, the cloud was the main
factor that caused the instability in the measurement of the
output voltage because it bloccked the sun, causing the
surrounding to be dim at certain times. As a result, the solar
panels were not able to receive thee maximum illumination from
the sun.

Figure 9. Output power comparison between static pannel and tracker

Figure 9 shows the graphs of output poower comparison

between the static panel and the tracker for dayy 1. For the solar
tracker, the highest output power produced was 1.24W at
1.00p.m while the lowest output power was 0.111W at 6.00p.m.
As for the static panel, the highest and the loweest output power
produced were 1.24W and 0.10W respectively. As presented in
the voltage and current graphs, the output poower graph also
shows that the output power produced by ssolar panel with Figure 11. Output current comparison between
b static panel and tracker
tracking system was higher than the output pow wer of static solar
panel at most of the times. Figure 11 shows the graphs of output current
comparison between the static pan nel and the tracker for day 2.
B. Day 2 As presented in the graph, the outp put current recorded for solar
panel with tracking system is high her than the output current of
static solar panel at most of the tim
mes. Nevertheless, as shown in
Figure 8, the value of output currrent for both panels recorded
the same number at certain times. This
T happened because at this
point, the location of the sun was similar for both panels. The
same situation also occurred for thee output voltage measurement
as shown in Figure 10. For the sollar tracker, the highest output
current recorded was 75.1mA at 12.45p.m while the lowest
output current was 6.5mA at 6.00 0p.m. As for the static panel,
the highest and the lowest output cu urrent recorded were 75.1mA
and 5.1mA respectively. As it caan be seen in Figure 10, the
cloud was also the main contributting factor for the instability
measurement of the output current.

Figure 10 : Output voltage comparison between static ppanel and tracker

Figure 10 shows the graph of output voltage

comparison between static panel and panel withh tracking system
for day 2. As it can be seen in the graph, thee output voltage
recorded for solar panel with tracking system iss higher than the
output voltage of static solar panel at most of thhe times. For the
solar tracker, the highest output voltage recordeed was 12.58V at
12.45p.m while the lowest output voltage was 12.12V at

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 2013 IEEE International Conference on Control System, Computing and Engineering, 29 Nov. - 1 Dec. 2013, Penang, Malaysia

current. By doing this, the output power will be larger compared

to using small solar panel. It is also recommended that the
measurement is improved by using a data tracker. All the
readings will be automatically recorrded in the data tracker.

REFERENCES

[1] Divya, V & Sashanka, P. April 30, 2010. “Renewable Energy”.

Retrieved June 5, 2012, from http:///www.yuvaengineers.com/?p=495
[2] Asmarashid Ponniran,Ammar Hashim,Ariffuddin Joret. “A Design of
Low Power Single Axis Solar Traacking System Regardless of Motor
Speed”.Internal Journal Of Intergraated Engineering,Vol.3 No.2(2011) p
5-9
[3] J.Beltran A.,J.L Gonzalez Rubio S.y C.D.Garcia-Beltran.
“Design,Manufacturing and Perform mance Test of a Solar Tracker Made
By a Embedded Control.Fourth Congress
C of Electronic,Robotic and
Automotive Mechanics
Figure 12 : Comparison the output power between static ppanel and tracker. [4] O.C.Vilela, N.Fraidenraich& C.Tiiba, (2003) “Photovoltaic pumping
systems driven by tracking colleectors. Experiments and simulation
Figure 12 shows the graphs of output power (2003) Solar Energy, 74 (1), pp. 45-52
comparison between the static panel and the trracker for day 2. [5] A.K. Saxena & V. Dutta, “A versatile microprocessor- based controller
for solar tracking”, IEEE Proc., 199
90, pp. 1105 – 1109.
For the solar tracker, the highest output poweer produced was [6] A.Yazidi, F. Betin, G. Notton &G G. A. Capolino, July 2006,"Low cost
0.94W at 12.45p.m while the lowest output powwer was 0.08W at two-axis solar tracker with high prrecision positioning”, Proceedings of
6.00p.m. As for the static panel, the highest and the lowest the International Symposium on Environment, Identities &
output power produced were 0.94W and 0.06W respectively. As Mediterranean Area (ISEIM’2006 6), July 10-13 2006, Corte-Ajaccio
(France), pp.211-216.
presented in the voltage and current graphs, thhe output power
graph also shows that the output power produceed by solar panel
with tracking system is higher than the outputt power of static
solar panel at most of the times.

As it can be seen in all the graphs, thee data for output

voltage, current and power during day 1 is moree stable than day
2. This was because day 1 was a very sunny daay which this led
to the maximum illumination obtained from thee sun at most of
the times, but for day 2, it was quite cloudy at ceertain times. The
cloud blocked the sun and caused the solar pannel not to receive
maximum illumination from the sun.

IV. CONCLUSION

In conclusion, the performance of dual-axxis solar tracking

system was successfully analyzed. Based on thhe data collected,
it can be concluded that the dual-axis solar traacking system is
better than the static solar panel in terms off output voltage,
current and power. For this reason, the system has been proven
effective for capturing maximum sunlight ssource for solar
harvesting applications. The economically and environmentally
friendly dual-axis solar tracking system also can be a great
technique in utilizing the superiority of solar eneergy thus solving
the increasing demand of electricity problem.

For further research in the future, some impprovement to the

system can be made in order to improve thee outcome. It is
recommended that the analysis to be done with a higher
intensity solar panel that produces higher outtput voltage and

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