Solar Tracking Systems: Design and Implementation

This assignment delves into the realm of solar tracking systems, focusing on their crucial role in enhancing the efficiency of photovoltaic (PV) energy generation. It examines various types of solar trackers, including single-axis and dual-axis systems, and explores the algorithms employed for sun position calculation. The document also discusses the implementation aspects of solar trackers, highlighting design considerations, control strategies, and real-world applications. A comprehensive review of relevant research papers and case studies is included to provide a thorough understanding of the current state and future prospects of solar tracking technology.

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AN EFFICIENT ENGINEERING METHOD TO MAXIMIZE PV OUTPUT FROM SOALR
PANEL

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Contents
AN EFFICIENT ENGINEERING METHOD TO MAXIMIZE PV OUTPUT FROM
SOALR PANEL...............................................................................................................................7
CHAPTER I: INTRODUCTION........................................................................................7
CHAPTER II: LITERATURE REVIEW.............................................................................8
SOLAR TRACKING.................................................................................................................10
SOLAR TRACKING METHODS............................................................................................11
SOLAR TRACKER PROTOTYPE..........................................................................................13
Passive Trackers.........................................................................................................14
Active Trackers..........................................................................................................15
Solar Tracking Viable Considerations.......................................................................20
Solar Tracking for Energy Efficiency........................................................................21
CORRELATIONS OF OPTIMUM TILTS ANGLE................................................................23
Solar Radiation Estimation on Tilted Surface...........................................................................25
Material and Methods - Electric Circuit....................................................................................29
PLC............................................................................................................................29
Signal Processing And Sensors Unit..........................................................................29
Microcontroller..........................................................................................................31
Monthly Comparison.................................................................................................................32
Key Point...................................................................................................................................33
Low-Cost Considerations..........................................................................................................34
CHAPTER III: METHODOLOGY...................................................................................35
CHAPTER IV: PRELIMINARY RESULTS.....................................................................37

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EXPERIMENTAL STUDIES AND RESULTS.......................................................................38
CONCLUSION..................................................................................................................40
REFERENCES..................................................................................................................41

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ABSTRACT
Solar energy is the easily available and catchable resource available at any point in the
world. So, exploitation of the solar energy is considered to be the best way to fulfill the day to
day electricity needs in the world. this renewable energy is easily available, however,
unfortunately, demands complex and expensive system to catch and convert it into the
conventional electrical energy used in the day to day need, though solar energy is available in the
nature, abundantly. Still, solar energy is considered as the best renewable energy, scalable and
sustainable energy that can meet the demands of the energy needs today and in the future. To
materialize this fact, a thorough research and development are demanded in basically, two
dimensions, first one to increase the efficiency of converting the solar energy to electrical energy
and second is to decrease the production cost, so that every home and family can afford to
implement and use it, as the best alternative to the conventional energy. This paper deals with the
best techniques and methods to increase the efficiency of the solar photovoltaic cells, through
producing highest possible output power.

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AN EFFICIENT ENGINEERING METHOD TO MAXIMIZE PV OUTPUT FROM SOALR
PANEL
CHAPTER I: INTRODUCTION
The fossil fuels dearth has rooted the most daunting challenges of exploring
and discovering the renewable and clean energy. Huge efforts are invested in
various conservation methods, like energy recycling, energy harvesting, towards
reduction in the usage of energy, in various commercial applications. Some of the
methods explored, for energy renewable sources usage, like hydro power, wind,
thermal power, solar power, tidal power, etc. Among them, solar power is
considered as one of the most possible and easier natural sources, because of the
low maintenance cost and ubiquitous characteristics of them(Sumathia, 2017).
As part of exploiting the sun and sunlight incident on the surface of the
earth, there are various techniques and methods developed and implemented so
that the energy obtained from the sunlight and solar power can be maximized to the
best extent. Among these techniques, solar tracking stands as one of the most
beneficial and viable one, to increase the solar power output, by following the
incidence angle close to zero with the sun. The solar tracking motion can be a
single axis tracker or dual axis tracker. The research continues to study the pros
and cons of these both techniques and the differences in the energy gain.
Solar tracking with the two optional techniques are explored in terms of
complexity, cost, and efficiency and majorly with the power output that can be
obtained by each of this techniques. Then the design aspects are decided based on
the viability and benefits of the respective techniques.

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CHAPTER II: LITERATURE REVIEW
The discovery of mechanism of photoelectric current has enabled the
technology to extract the electricity usable from the sun. It then enabled the solar
cell development subsequently, which is a semi conductive material capable of
converting direct current from the visible light. Generation of the DC voltage is
then made possible with arrays of solar cells, connecting electrically.
The technology of generation of alternative power source has been achieving
increased popularity, increasingly from the shortcomings of fossil fuel realization.
However, solar power is generated moderately, because of more expensive solar
cells, relatively and lower efficiency of conversion of them. Eventually, solar
alternative power generation has been researched heavily, to decrease cents per
kW/h and increased its usage compared to the other alternative power sources,
such as Hydro, Wind, Geothermal, etc.
The lower efficiency is because of the reduced storage losses, inverter losses
and light gathering losses. The emphasis here to increase the solar power is the
incidence of the source of light that provides the power, from the sun. So, angle of
incidence is directly proportional to the gathering of the light, from the surface of
the solar cell, and greater the power, when it is closer to perpendicular incidence.
When the surface of the solar panel is fixed, the incidence angle would be near 900,
in the evening and morning and then the cell’s ability to gather light would be zero
that results to zero output (Sumathia, 2017). And the incidence angel would be
zero, during the mid day and maximum output of power collected by the surface of
the cell, since light incidence is perpendicular, on the panel.

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So, the key to increase the efficiency and power output is to maintain the
incidence angle to 00, to the possible extent. It can be achieved by solar panel tilt,
to face the sun, consistently. This sensing and tracking or following the sun in real
time, is called solar tracking.
SOLAR TRACKING
Since solar power is available for about ten hours, everyday, it can be the
best utilized. So, there have been various techniques developed and implemented,
towards maximizing the solar power and energy obtained. Solar tracking is one of
such techniques. Solar tracking is done in one of two techniques called 1 axis
tracker and dual axis tracker.
Figure: Curves of Load Power for Fixed and Tracking Systems (Al-
Mohamed, 2004)

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The above figure shows increased load power for moved or tracking system
that ranges for more time period too.
Figure: Improvement of Power in Different Periods during Day (Al-
Mohamed, 2004)
The improvement of power in tracking system can be understood and
analyzed from the above figure.
SOLAR TRACKING METHODS
The simple method for solar tracking is to use a Light Dependent Resistor
that can detect the changes of light intensity, on the resistor’s surface. Two
phototransistors can also be used, as an optimal method for tracking process.

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Figure: Solar Tracking Method (Rizk & Chaiko, 2008)
During the morning period, tracker would be in the state of A, turning the
left phototransistor on and result in motor turn on. This process is continued till
tracker is moved to state B, returning the shadow from the plate. Later state C is
shortly reached, as the progress of the day and turns the right phototransistor on.
Turning of motor continues till reaching of the minimum level of detectable light.
The design has a challenge that the sensitivity range is narrow, because of
the phototransistors used and with bias conditions. So, better method can be
proposed with the set-up of a simple triangle, taking two solar cells and connecting
in opposite directions, as shown n the figure below.
Figure: Solar Reference Cells Set up (Rizk & Chaiko, 2008)
So, the set-up makes lighter to fall over one of its solar cells and increased
potential, resulting in difference of voltage between the two cells. The design
would result in signal to detect, at each cell, however, at mid-day the light fall is
less, because of varied incidence angle.

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SOLAR TRACKER PROTOTYPE
Finally, a motor circuit has to be mounted and coupled with the circuit and
the final circuit can be shown as the figure, below.
Figure: A solar Tracker Prototype (Rizk & Chaiko, 2008)
Then the experiment was tested by employing the fixed panel surface by
removing the tracking system and another, by employing the tracking system (Rizk
& Chaiko, 2008). The resulting readings have shown the changes in the output
powers obtained in these two conditions.

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Figure: Graph for Difference in Power Output (Rizk & Chaiko, 2008)
The results are obtained after a period of 12 hour, as follows.
Surface Output
Power
Average
Power
Average
Percentage
Fixed 9W 3.51W 39%
Tracking 9W 6.3W 71%
Table: Fixed and Tracking Systems
During the later and earlier periods of day, fixed panel power increase is up
to 400%, with an average of 30% increase of power, when the solar panel is
maintained in perpendicular position to the sun, to the possible extent. (Rizk &
Chaiko, 2008)
The method and mechanism of the solar tracker has its objective to follow
the direction of sun, so that maximum power can be extracted. The possible drive
types can be as the following.
Passive Trackers
The passive tracker follows the principle that solar heat is taken as an input
for an imbalance and it leads to the tracker movement, working on thermal
expansion and employing either shape memory alloys or low boiling point fluid of
compressed gas.
Passive trackers have a fewer applications, because the applications of CSP
(Concentrating Solar Power) demand higher precision, efficiency and higher
degree of complexity. But they have applications in the regular flat PV systems
(Sumathia, 2017).

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A passive tracker with single axis is designed with lost cost based on SMA
(Shape Memory Alloy) actuators, since this actuator can be deformed easily, with
even lower temperatures. So, when it is heated above the temperature of
transformation, mechanical work is produced and original shape is returned.
The experimental study proved that passive tracker can provided about 2%
of efficiency.
Active Trackers
The active tracker can have better control over the tracker, by the
mechanisms of gear and motors, for better direction and magnitude. These are
widely used, for its accuracy and efficiency, however, needs additional power and
energy consumption.
Single-Axis System
The system of single-axis offers one degree, acting as the rotation axis. So,
they have lesser complexity and consume only small energy, compared to the
system of multi-axes.

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Figure: Rotation Angle Scheme (Sumathia, 2017)
An experimental study was performed and 3 position 1 axis PV with sun
tracking system, mounting on the building wall, for operating in total three
different angles, as shown in the figure above. The PV mounting frame is set to
turn with a DC motor and structural design. The tracker turning is enabled with a
timer IC, offering the time signal, for motor triggering, to turn the angle of turning.
A microcontroller is used for implementing control algorithm (Huang et al.,
2011)
This typical system of PV standalone, has a servo motor, PV panel, LDR
sensors, PV panel, microcontroller and external load. Motor is set for single-axis
rotation freedom.

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Different experimental studies were performed with single axis angle and
the results are reported and recorded comparing with the radiation collected from a
regular horizontal surface (Sumathia, 2017). They report from conclusion that a tilt
of horizontal surface, raising optimal angles, at about 30.2% more radiation, in one
year. However, when a two axis azimuthally is compared, about 72% of more
radiation is recorded.
The azimuth schematic diagram can be as follows, for a tracking of three
steps (Bin et al., 2011)
Figure: Azimuth Three Step Tracking Schematic Diagram (Sumathia, 2017)
According to Chang (Chang, 2009), the tracking panel performance with
varied latitudes, time periods and types of radiation, concluded that the single axis,
east-west oriented system has lesser yearly gains, compared to north-south.

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When compared to the non-tracking collector of CPC (Compound Parabolic
Concentrator), one-axis system increases the optical efficiencies. But there were
significant effects, with even smaller errors in tracking.
Further analysis is done with two positional tracking system daily
(Tomson, 2008) and positions, both symmetrical and asymmetrical, derived in
the axis of north and south. More gain is obtained with two positional exposures.
45 degrees of tilted collector and South-East direction, with westward +60 degrees
deflection and -30 degrees of eastward deflection gave maximum gain.
When solar tracker was employed to test at varied day times, the following
readings are found, as shown in the following table.
Weather Time With
Tracking
With no
Tracking
Sunny 9 AM 21.8 V 20.5 V
1 PM 22.6 V 21.5 V
5: 30
PM
19.5 V 18 V
Cloudy 9 AM 18.8 V 18.4 V
1 PM 19 V 18.6 V
5: 30
PM
18.2 V 18 V
Table: Solar Tracking Results in Sunny and Cloudy Weathers
There are more differences in voltages, during sunny conditions, from the
Table above.

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Double-Axis System
It gives freedom with two degrees and acts as rotation axes and are set in
perpendicular directions to each other, giving better accuracy, from more complex
control system. It makes uses of normal tracking and daily adjustment strategies.
Normal strategy has smaller tracking errors and improves performances.
In certain areas, the techniques for solar tracking are found to be unsuitable,
for low solar resource areas, because of stronger correlation in between solar
resources, found in that area and increase of solar gain, yearly.
A multi-axes electromechanical system can be designed and implemented,
through PLC (Programmable Logic Control), for tracking the sun, and calculate
solar altitude and azimuth angles, according to Sungur (Sungur,
2009). This system minimized the errors.
Two axis tracking collectors are incorporated by Njoky, for energy
generation improvement through solar PV system.

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Figure: Two Axis Tracking PV Collector Surface – Illustration (Sumathia,
2017)
Rotation about the central axes can be observed from the above figure, for
the same system (Njoku 2016). Oner et al., designed microcontroller controlling
spherical motor, for solar tracking precisely and found that the motor can move the
panel in both vertical and horizontal axes, instead of two different motors for each
axis (Oner et al, 2009).
When both one and two axes trackers are experimented with sun zenith,
azimuth, solpe and surface azimuth angles, for surfaces of optimum geometry of
fixed and tracking, two axis tracking surface provide maximum radiation beam
possible, when sun and surface azimuth are equal and when Zenith and surface
slopes are equal, according to Braun et al. (Braun 1983)
MPPT
Solar panels MPP (Maximum Power Point) and efficiency improvement can
be achieved by an algorithm called MPPT or Maximum Power Point Tracker,
according to Huang et al. (Huang et al. 2012). The technique is to implement
the operations called SDT (Slope Detection Tracking) and open circuit tracking, for
raising the accuracy and tracking speed. Here, SDT increase the duty cycle of
switching and so solar panel current is also increased, ensuring the MPP operation.
When static MPPT technique is considered, the technique of golden section
provided 99.43% of rate of efficiency, which is more, in lesser response time. And
dynamic tracking is more preferable for its 99.602% of efficiency, in 0.025s
convergence time, when the complexity level is low (Kheldoun et al., 2016).

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Solar Tracking Viable Considerations
A new hybrid control strategy is presented by Rubio et al., for more accurate
sun tracking and energy saving factors. Algorithm is developed to work in two
modes,
1. Normal mode of tracking, when sunlight is sufficient
2. Otherwise, search mode
It showed that this model gave more energy generation (Rubio et al,
2007). An interesting algorithm is proposed for sun position calculation, for sun
tracking without using the sensors. The algorithm calculated elevation and azimuth
sun angles in horizontal coordinates. It improved 49% of energy efficiency and
suitable for the applications, where there is no requirement of more accuracy
(Rizvi et al, 2014).
A new system with tracking and cleaning is proposed and improved 30% of
energy generation than without cleaning. It used 8051 microprocessor, gearbox
coupling to stepper motor along with a mechanism of sliding brush (Tejwani &
Solanki 2010).
The reception of the irradiation is tested to be the same for both the systems
of one and two axis, but the later cost is much more than the former one. They
reported 54% of more irradiance is more compared to fixed systems and both have
received surplus energy of 34% and 38% (Nann, 1990).
The gain of the PV tracking system can be improved to 40%, by V-trough
concentrator implementation, by using amorphous Silicon solar cell (Shaltout et
al, 1995).

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Solar Tracking for Energy Efficiency
Tracking helps reducing the incidence angle in between panel and incoming
light and increases the energy produced, in the PV systems
Optimum tracking strategy was studied, for solar PV system, in higher
latitudes and concluded that integrated solar radiation incident over the horizontal
plane theoretical value estimation shows that PV panel on a horizontal plane
produces increased energy compared the one tracking or following the sun. So, the
study concluded that option of tracking is viable, only during partly cloudy or clear
sun (Guillermo et al, 2015).
When active solar tracker of one axis is designed, modelled and tested, 20%
increase is shown in efficiency than the design of fixed panel, through there are
slight deviations, in the periods of afternoon and evening, because of wind loading,
mechanical friction, etc. (Chin et al, 2011).
According to Yao et al. (Yao et al, 2014), normal tracking strategy
obtained more power output than the system of fixed PV. About 31.8% of more
efficiency is obtained with the tracking process.
The tracking system energy efficiency is studied with energy absorption
model, by Zhang et al., revealed that the energy absorption is too less and tracking
is unsuitable for the too high latitude of 85 to 90 degrees, though 36% of energy
efficiency average value, for a year can be obtained, theoretically.

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An increase of 42.6% energy is obtained from the multi-axes sun tracking
system, when controlled by an along module and PLC, at 37.6 degrees of latitude,
compared to fixed PV panels (Cemil, 2009). Solar tracking offers uniform
distribution of energy and its gain, for the entire day and so is more efficient
(Pratik, et al, 2015).
Distributed MPPT module helps PV system efficiency optimization,
especially, in partial shading on the system conditions, compared to centralized
MPPT. It can compensate the loss of generating capacity, because of the problems
of mismatch to 50%, according to Mei-xia et al. (Mei-xia et al, 2012).
According to Mei-xia et al., when the centralized and distributed MPPT
output characteristics for PV panels are analyzed, and found that DMPPT can have
96.54% of efficiency delivery with full possible efficiency capacity of 98.41% that
is more than the European and CEC efficiency, even at 10% of power point,
indicating potential to great generation efficiency improvement (Mei-xia et al,
2012).
Solar tracking efficiency is tested and experimented for efficiency in cold
and hot climates. In Egypt, a hot climate, there is only 8.16% of energy gain in hot
climate, compared to the no tracking and such low output is because of the panel
overheating with consumption of total energy generated to 5.89%, out of total
generated energy in sunny day. In Berlin, with solar irradiance and low ambient
temperature, there was 40% of energy gain more than non-tracking panel, giving
30% of final energy gain, after subtracting 10% of consumption by tracker. So,
solar tracker system is unsuitable for the extremely hot climates (Eldin et al,
2016).

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The average performance ration of PV system, rp is close to 0.75, for 2-axis
solar tracking, in Nigeria and it is increased with latitude. About 20% to 40% of
more production of energy found, according to Njoku (Njoku, 2016).
According to Quesada et al., sun tracking system is unsuitable in cloudy
days, during the summer, during the conditions, IH (global solar radiation incident
over the horizontal plane), is lower than Ic (critical radiation), producing 25%
lesser generation of energy, than horizontal panels (Guillermo et al, 2015).
CORRELATIONS OF OPTIMUM TILTS ANGLE
The overall efficiency and power output of the solar tracking PV panel can
be made optimum with the tilts angle and their correlation, since the solar radiation
reaching the panels of photovoltaic would be varied according to the changes of
the corresponding tilt angles. The other factors are the geographic position,
conditions of local climate and usage time period. The tilt angel choice by the
engineer can be simplified by the correlations (Enslin 1992).
1. Optimum slope correlations for solar energy received
The daily optimal angle can be obtained by the extra terrestrial radiation
incident equation derivation, on a plane collector that faces towards south,
so, Sopt is considered as the tilt angle, δ as the declination and L, as the
latitude.
Equation I
----------------------- (1)

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The correlation for monthly optimum angle can be proposed as the
following.
From the month of January to March, so M varying from 1 to 3
Sopt = 60.00012 + 1.49986M + 3.49996M2 + (L-30) (0.7901 + 0.01749m +
0.0165M2) --------------------------------------------------------------------- (2)
For the months, from 4 to 6,
Sopt = 216.0786 + 72.03219M + 6.00312M2 + (L-40) (1.07515 + 0.11244M +
0.03749M2) ---------------------------------------------------------------- (3)
For the month, M value from 7 to 9,
Sopt = 29.11831 – 20.52981M + 2.50186M2 + (L-50) (-11.17256+
2.70569M+ 0.15035M2) --------------------------------------------------------(4)
For the months, M from 10 to 12,
Sopt = -441.2385+ 84.54332 M - 3.50196M2 + (L-340) (4.2137 - 0.54834M +
0.0223M2) ----------------------------------------------------------------------- (5)
The equation (2) is further corrected by Souleyman (4) and then obtained as,
Sopt = 60.00012 + 1.49986 M – 3.49996 M2 + (L-30) (0.7901 + 0.01749 M
+0.0165 M2) -------------------------------------------------------------------- (6)
Another correlation was proposed by Trisis (5), with the measured data, as
the following.
Sopt = 35.15 – 1.39 δ – 0.007 δ2 – 4.26 x 10 -5 δ3 -------------------------- (7)

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2. Optimum slope correlations for the system of photovoltaic
The orientation and tilt angle are important for the module of the
photovoltaic, as factors, influencing the overall performance of them. (Hussein
et al, 2004). According to the experiments and studies conducted by Tsalides et
al., (Tsalides & Thanailakis, 1985), the tilt angel effect on the generator of the
photovoltaic, by optimum tilt angle calculation, for the 1960 to 1983 period, in
the geographical location of Athens. The studies have concluded that the
photovoltaic panel inclination optimum angle is found to be average annual
clearness factor linear function, KT.
Sopt = 70.5 KT + 24.125 -------------------------------------------------------(8)
Then the correlation is found to have the regression coefficient of 0.96.
Correlations are validated by connecting the photovoltaic panel to a fixed
resistor, according to El-Kassaby (El-Kassaby, 1988). The system tested has not
been contained most extraction of power, however, good results are obtained by the
correlations developed (Mraoui et al, 2014).
Solar Radiation Estimation on Tilted Surface
Solar energy measurement is done for the purpose of recording the diffuse
and global radiation on a horizontal plane. The radiation over the surface tilt would
be calculated, along with the precision related, from the parameters measured and
the position of the sun in the sky (Mraoui et al, 2014).
So, the position of the sun can be calculated by the number of the day, N,
local geographical coordinates and the solar time and they have to be well known.
From this set of data, hour angle, and solar declination, that are taken as

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coordinates of horizontal and solar altitude, with respective to the instantaneous
azimuth, a (Mraoui et al, 2014).
Figure: Reception of Radiation on Tilted Surface (Mraoui et al, 2014)
The above figure shows the radiation of solar on the arbitrary surface that
has S, the inclination, according to the horizontal. It is calculated as sum of sky
diffuse radiation (G d,s) and beam radiation (G b, s) and the reflected radiation on
ground (G gr, s) (J. A. Duffie and W. A. Beckman, Solar Engineering of thermal
processes, 3rd ed. John Willey and Sons, 2006).
So, G T,S = G b,s + G d, s + G gr,s --------------------------------------------------- (9)
Let us assume that the diffuse distribution of the solar radiation is isotropic,
in the atmosphere,the value can be obtained over the tilted surface, by measured
diffuse radiation multiplication, through the view factor over the sky on the
horizontal surface (Duffie & Beckman, 2006).
----------------------------------------------------------- (10)
A simple method is presented by isotropic model, for the diffuse solar
radiation evaluation, over the inclined plane. But the solar radiation received is
underestimated by the model, especially, for the conditions of the clear sky. Here, it
makes use of the Perez Anisotropic model (Perez et al, 1990).
The diffuse radiation would be split into three different components, by this
model. These components are the horizon that can brighten the radiation, the

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circumsolar radiation that surrounds the disk of the sun and the diffuse radiation,
distributed, isotropically, from the sky of the rest.
------------- (11)
Here,
F1 = coefficient of circumsolar brightness
F2 = coefficient of horizon brightening
a1 = max (0, Cos(θi))
and
a2 = max (Cos(85), Cos(90-h))
Then the solar radiation from ground reflection can be calculated by the total
horizontal surface radiation by the ground reflectance and the view factor, relative,
to the ground.
Here, ρ is the factor of ground reflectance, depending majorly over the
properties of soil reflectance. The study uses the value of 0.3 for Ghardaia and 0.2
for Algiers.
The Data Used
The study made use of the data measurement, after collecting and recording
from two different geographical locations, called Ghardaia site and Algerian site.
Here, the Ghardaia site is located in the Algeria’s desert, towards north, with the
altitude of 468m, longitude of 3.80E and latitude of 32.40N and the site, Algerian is
located towards northern part of the Algeria, with 345m, longitude of 3.80E and
latitude of 36.80N.

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The climate of Ghardaia is categorized as the arid dry and hot, or BWh and
the Algiers climate is more of temperature climate having dry and hot summer,
Csa, according to the classification of the Koppen-Geiger.
The parameters collected here are the radiometric, principally, such as global
radiation incident over the tilted surface at the latitude site, diffuse solar radiation
and horizontal global radiation and direct radiation. All these parameters are
collected. The study also collected some of the parameters of weather, like
atmospheric pressure, relative humidity and air temperature that is dry.
The pyrheliometers mounted over tracker of 2AP dual axis and positioned,
which is used to provide the sun reliable positioning measures the directed
radiation. The diffuse irradiance can also be measured by the ability of 2AP having
Shading Ball Assembly, with pyranometers that are mounted properly. Here, the
radiometric devices used are in compliance with the secondary standard of ISO and
the rate of error would not exceed 2%. And the meteorological devices error also
would not exceed 3%.
Material and Methods - Electric Circuit
The solar tracking PV panel system has its electronic circuit, on the basis of
two photo resistors resistivity comparison.
PLC
The fact identified is that the maximum radiation from the sun can be
received by the PV module, or solar collector, when the rays of the sun strike them
in right angles. So, optimal angle of tilt is dependent on the application of the solar
power system and latitude of the site.
A unit of programmable logic controlling can be used for the system of sun
tracking in single axis. The control operation can be obtained by developing

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controlling program, suitably. And it becomes the heart of the solar tracking
system.
Signal Processing And Sensors Unit
The position of the sun can be tracked with symmetric photo-resistors,
positioning in the PV solar module holder and shadowing is provided for one
resistor out of two, by separating them with a solid barrier. When the more sunlight
gets incident on the resistors surface, their values are decreased. It allows
decreasing the resistivity and so dropping of voltage across the resistor. Then drop
of voltage is increased on the variable resistor (Al-Mohamad, 2004).
PLC Program for Control and Monitoring
The tracking system can be well controlled through program customized for
the PLC, with the benefits of,
1. Controlling the movement of the tracking system
2. Monitoring the outputs and inputs of the PLC
3. Storage of samples
PLC Program for Data-Handling
Special programs built for effective tracking system, such as,
1. Automotive port detection
2. System monitoring
3. Display of the system of sun tracking
4. Movements of the module, towards forward and backward, in the situations
unexpected
The screen that shows the overall functions of the tracking system can be
seen as in the following figure.

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Figure: Screen for Control and Monitoring (Al-Mohamd, 2004)
Microcontroller
The solar tracking system, either with the single axis or dual axis, it is
implemented with the help of the microcontroller. So, every solar PV system that is
referred to design in the recent and in the future would be based on the
microcontroller that is used to automate the processes that they are intended to do.
The motion of the solar tracker and its associated measuring functions, generation
of the photovoltaic and the central and control algorithms are built in the
microcontroller and so it implements the basic function and program of the solar
system.
The function of the microcontroller in the solar tracking system is started by
receiving the inputs from the Light Dependent Resistors, which pass the intensity
of light, incident from the sun. The input from the LDR would be then processed
and the microcontroller enables the functions of the processing units, such as
enabling the motor driver to operate and turn the solar panel to respective

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direction. The stepper motor would be driven by the motor driver, in the greater
illumination direction, by turning the panel, of one step at one time. The motor
continues to move, till the sensor values difference would reach below the value of
threshold. So, every microcontroller in the solar tracking system is designed and
built to receive the input from the sun and enable the processing units to achieve
the output, required, in terms of output power.
So, every photovoltaic standalone solar tracking system has basically a panel
made with photovoltaic, battery, servo motor, LDR sensors, charger and external
load, along with the microcontroller to enable the function of the solar system.
Monthly Comparison
The fixed sun tracking PV panels and single and dual axis solar tracking PV
panels are also compared, in terms of their gains, in each month of the year.
Month Sun-Tracking
Fixed systems
Two-axes and
Single axis Systems
Gains in
percentage
Gains in
percentage
January 9.03 12.16
February 13.19 17.33
March 17.72 21.30
April 30.60 25.06
May 42.91 29.22
June 48.77 31.14
July 49.02 32.09
August 35.30 27.07
September 25.06 26.89

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October 14.46 18.75
November 10.52 14.32
December 8.93 12.70
Table: Monthly Gains for Fixed Tracking and 1 and 2 Axis Tracking
Systems
Key Point
From the literature reviewed from the available resources, the key point can
be conceived as the mechanism of electrical energy produced from the global solar
irradiance collected that depends again on the ways of tracking the sun accurately,
by the system. Among various mechanisms and designs developed and
implemented in the study, a significant mechanism can be understood as the two
axis solar tracking that has achieved the capability to track the sun continuously,
resulting in receiving the solar beam on the surface with the key incidence angle
value, zero. It shows definite improvement compared to the traditional fixed
system and single axis sun tracking systems. The system of single rotating axis, in
various studies tracked the sun azimuthally, only consequently, the system’s
incidence angle to follow the position of the sun, based primarily on the panel
slope and rotating axis choice.
Performance or Maximum Output Considerations
Crystalline silicon PV panels deteriorate performance, when heated.
Moharram et al. Research concluded that the PV panels temperature coefficient,
indicating decrease of 0.5% efficiency, by 10 of rise of temperature (Moharram
et al, 2013).
Solar tracking is beneficial and high performing, in the countries that are
cold and cloudy, instead of the sun-belt countries, according to the experimental
studies, by Eldin et al. (Eldin et al, 2016).

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Solar tracker working range can be increased with LDR special arrangement
for a solar tracker of three dimensional, PLC helps solar tracker position control
and 3D solar panel have better capacity to produce increased energy, compared to
the traditional one, according to Pratik et al (Pratik et al, 2015).
PV panel performance can be increased with hybrid sun-wind tracking
system that combines system of dual-axes along with the system of wind-tracking
for PV panel cooling. It increased 49.83% of performance compared to
conventional system. And wind-tracking system can complement the tracking of
dual-axis, during windy conditions and works as an auxiliary system (Masoud et
al, 2015).
According to Koyuncu et al., sun tracking system with two-axis
microprocessor, optimum energy is received, as long as the panel plane is
maintained to be normal to the sun (Koyuncu, 1991).
Efficiency of dual axes solar panel is increased significantly, with timer and
mechanism of dual axes LDR sensor.
Low-Cost Considerations
According to Laughlim et al (Laughlin et al, 2013), the installation
costs can be reduced with two axis solar tracker of low profile, by securing the
system towards the ground and improving the density of packing through smaller
shadow footprint creation, compared to the regular trackers.

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The cost of the one axis three panels is not more than a system of fixed PV
rooftop (Huang et al, 2011).
Cost effectiveness and performance of the tracking system, at various modes
are analyzed by Michaelides et al. The three modes are seasonal tracking, adjusting
the slope, one axis tracking, with azimuth variation and fixed surface at 40 degrees
to horizontal. The study used simulation program, TRYNSYS and concluded that
the best performance mode is the single tracking system, with the annual friction
for
Single tracking – 87.6%
Seasonal tracking – 81.6%
Fixed tracking – 79.7%
However, fixed tracking is most cost-effective (Michaelides et al,
1999).
CHAPTER III: METHODOLOGY
The research conducted for “An efficient engineering method to maximize
PV output from Solar Panel” has been started from an effort of understanding the
meaning of the solar tracking. Initially, an attempt is made to search and find the
basic literature from the library and internet resources. Authenticated resources are
collected as PDFs. Then all the resources are arranged in the logical sequence to
read and understand.
A detailed understanding of the solar tracking is attempted, so that the basic
technology involved in the solar tracking is explored. Then the key question to
increase the performance and efficiency of the solar tracking is attempted to
explore. Eventually, incidence angle is considered as a key and significant factor

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for increasing the power output and so can increase the efficiency of the overall,
going back to the basics (Sumathia, 2017).
The literature has shown several experiments conducted by the experts
previously. Each of the experiment has been studied and the details of each of the
experiment are recorded. The recorded details and readings of the experiments
have been reviewed to understand the key factors to increase the power output to
maximize the output of the photovoltaic panels. The exploration gave the key
methods of increasing the tracking effect of the solar panel. Single axis and dual
axes solar tracking panel system has been explored in detail in the study. The
literature has been explored and reviewed to understand the methods to maintain
the incidence angle of the solar panel surface, by the solar panel, with the process
of tracking. The detailed methodologies are studied.
The research is further extended, after a fair understanding of the solar
tracking system and its optimizing methods. A fair idea has been developed after a
clear understanding of the key factors that can improve and increase the power
output of the PV cells.
There are several current commercial solar tracking systems available with
the microcontrollers. Initially, microcontrollers have only limited function,
however, with the advancement of the technology, microcontrollers have got
master control of the solar tracking system. So, each and every key component
used in the solar tracking system is controlled by the built-in programs of the
microcontrollers. The master control microcontroller ensures the operation of each
of the component and unit and ensures that the incident angle is maintained close
to zero, with the sun.
The design aspects are reviewed and analyzed for the design of the solar
tracking system with PV cells. The design is going to be with the dual axis solar
tracking system, since higher output power is the aim of the research. Another

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important aspect and consideration of the efficient solar PV panel is the
consideration of the cost.
The cost of the solar panel is expensive, when the dual axis system is
considered to develop. It is because of the increased complexity and expensive
hardware required for the design of the system. So, MPPT algorithm is considered
to employ the methodology that can reduce the need of the hardware and improve
the efficiency and power output of the PV panel, with solar tracking system.
The final design would then be simulated in MATLAB and the results will
be obtained, for comparison with theoretical results.
CHAPTER IV: PRELIMINARY RESULTS
Tracking systems are designed and implemented with single and dual axes.
The objective of single axis tracker is to follow the apparanet movement of sun
from east to west and the dual axis tilts the solar module or collector, for tracking
the changing altitude angel of the sun, in addition to the tracking from east to west.
EXPERIMENTAL STUDIES AND RESULTS
1. Bifacial modules that are mounted over the sun tracker of polar axis
have the ability to grab about 1.7 times of the global solar radiation energy, when
the static modules and mono facial modules are compared, according to Oria et al.
(Oria, & Sala, 1988).
2. There is about 36% of increased output of annual energy received, by
employing the sun tracking system of dual axis, when the PV system of fixed
latitude tilted are compared, according to Chander et al (Chander, M & Chopra,
1988).
3. About 42% and 36% of power generation gains are obtained in the
mid latitude region, when the dual axis and single axis systems are used for sun

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tracking, respectively, when compared to the photovoltaic system with fixed
arrangement, according to Neville (Neville, 1978).
4. Optimal tilt angles and optimal orientation for collectors of the flat
plate solar, in Egypt can be found and obtained by the mathematical model
development and the concluded that the total 29.2% of total additional energy can
be achieved, by changing the title angles as well as the orientation, on daily basis,
when compared to the fixed panels, according to Morcos (Morcos, 1994).
5. The photovoltaic modules that got mounted over the sun tracker of
dual axes performance was studied by Kaira et al. (Kacira et al, 2004) and
concluded that about 29.3% and 34.6% of additional radiation of solar and
production of electrical power, reached respectively, compared to the fixed PV
panel, in Turkey, on specific day in the month of July.
6. According to Chang (Chang, 2008), the one axis solar tracking panel
gain is considered, to extraterrestrial radiation following and concluded that the
36.3% and 62.1% solar radiation gains are obtained, for specific four days, in the
year, and for specific four seasons, it is found to be in between 37.8% and 60%.
The solar radiation gains are obtained to 49% when considered throughout the
year.
7. In a theoretical study presented by Chang (Chang, 2009), the output of
the electrical PV module in varied tilt angles and azimuth angles in Taiwan and the
PV module mounted gain over the sun tracking of single axis is analyzed against
the fixed panel. The study and analysis indicate that the gains yearly, achieved
from the observed, predicted and extraterrestrial radiations are 18.5%, 28.5% and
51.4%, when a PV panel with single axis is installed. About 17.5%, 25.9% and
45.3% of the same parameters are obtained, when optimum slope is considered in
the installed single axis tracking solar panel. Here, the optimum angle is adjusted
for the PV panel, for each of the months.

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8. Another theoretical study conducted by Chang, in the third study,
(Chang, 2009). The study is conducted over the oriented single axis in the East-
West and concluded that the gains achieved are much lesser compared to
orientation of the North to South, panels of single-axis systems. So, for the
observed, predicted and extraterrestrial radiations, the obtained improvements in
the gains obtained are, 7.4%, 13.5% and 21.2%.
9. A new mechanism was developed for the sun tracking system of one
axis by Huang et al (Huang et al, 2007), having adjustment positions of three fixed
angles, in the morning, in the noon and in the afternoon periods and the mechanism
has achieved 24.5% of increased generation of power, compared to the fixed
panels.
10. A multi-axes system for sun tracking has been designed and
constructed, in three axes, East-West, North-South and Vertical), by Abu-Khader
(Abu-Khader et al., 2008). The findings from the study are that there is an overall
improvement of output power to 30% to 45%, from the axes tracking system of
North to South, when compared to the system of fixed PV panel.
CONCLUSION
The mechanism of sun tracking increases the solar energy radiation,
receiving from the photo voltaic modules or solar collectors, resulting in increased
harnessing of output power daily and annually, when compared to the fixed solar
panel system. At the same time the tracking system usage is offered with more
complex and more expensive deal, for an average increase of more than 25% of
more output power, compared to the fixed solar PV panel system
Solar tracking system can be optimized with single and dual axis systems
that can increase the power output compared to the fixed solar tracking system.

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The purpose of the single and dual axis systems is to maintain zero incidence
angles with the progression and movement of the sun.
Though tracking with PLC technologies towards tracking system control and
solar panel monitoring are increasingly complex and expensive, compared to the
fixed ones, when these are used for the applications of controlling with more
modules, deployed simultaneously, can become cost effective, as this system can
obtain increased power output for throughout year.
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