Dual Axis Solar Tracking System - MECHANICAL ENGINEERING PROJECT REPORT
CHAPTER 1
INTRODUCTION
With the unavoidable shortage of
fossil fuel sources in the future, renewable types of energy have become a
topic of interest for researchers, technicians, investors and decision makers
all around the world. New types of energy that are getting attention include
hydroelectricity, bio-energy, solar, wind and geothermal energy, tidal power
and wave power. Because of their renewability, they are considered as
favourable replacements for fossil fuel sources. Among those types of energy,
solar photovoltaic (PV) energy is one of the most available resources. This
technology has been adopted more widely for residential use nowadays, thanks to
research and development activities to improve solar cells’ performance and
lower the cost. According to International Energy Agency (IEA), worldwide PV
capacity has grown at 49% per year on average since early 2000s. Solar PV
energy is highly expected to become a major source of power in the future.
However, despite the advantages,
solar PV energy is still far from replacing traditional sources on the market.
It is still a challenge to maximise power output of PV systems in areas that
don’t receive a large amount of solar radiation. We still need more advanced
technologies from manufacturers to improve the capability of PV materials, but
improvement of system design and module construction is a feasible approach to
make solar PV power more efficient, thus being a reliable choice for customers.
Aiming for that purpose, this project had been carried out to support the
development of such promising technology.
One of the main methods of
increasing efficiency is to maximise the duration of exposure to the Sun.
Tracking systems help achieve this by keeping PV solar panels aligned at the
appropriate angle with the sun rays at any time. The goal of this project is to
build a prototype of light tracking system at smaller scale, but the design can
be applied for any solar energy system in practice. It is also expected from
this project a quantitative measurement of how well tracking system performs
compared to system with fixed mounting method.
CHAPTER 2
LITERATURE REVIEW
[1]
Hossein Mousazadeh et Al.,[ (2011), Journal of Solar Energy Engineering,Vol.133
studied and investigated maximization of
collected energy from a non-board PV array, on a solar assist plug-in hybrid
electric tractor (SAPHT). Using four light dependent resistive sensors a sun-
tracking system on a mobile structure was constructed and evaluated. The
experimental tests using the sun-tracking system showed that 30% more energy
was collected in comparison to that of the horizontally fixed mode. Four LDR
sensors were used to sense the direct beams of sun. Each pair of LDRs was
separated by an obstruction as a shading device. A microcontroller based
electronic drive board was used as an interface between the hardware and the
software. For driving of each motor, a power MOSFET was used to control the
actuators. The experimental results indicated that the designed system was very
robust and effective.
[2]
K.S. Madhu et al., (2012) International Journal of Scientific & Engineering
Research vol. 3, 2229–5518, states that a single axis tracker tracks the sun
east to west, and a two-axis tracker tracks the daily east to west movement of
the sun and the seasonal declination movement of the sun. Concentrates solar
power systems use lenses or mirrors and tracking systems to focus a large area
of sunlight into a small beam. PV converts light into electric current using
the photoelectric effect. Solar power is the conversion of sunlight into
electricity. Test results indicate that the increase in power efficiency of
tracking solar plate in normal days is 26 to 38% compared to fixed plate. And
during cloudy or rainy days it’s varies at any level.
CHAPTER 3
PROBLEM STATEMENT
A sunlight based tracker is utilized
as a part of different frameworks for the change of saddling of sun powered
radiation. The issue that is postured is the usage of a framework which is fit
for improving creation of energy by 30-40%. The control circuit is actualized
by the microcontroller. The control circuit at that point positions the engine
that is utilized to situate the sun oriented board ideally.
3.1 Existing System
The existing dual-axis solar
tracking system project aims to enhance solar panel efficiency by optimizing
the capture of sunlight throughout the day. This innovative system utilizes a
combination of sensors, actuators, and control algorithms to precisely orient
solar panels in alignment with the sun's position.
The system consists of two main
axes: the azimuth and elevation axes. The azimuth axis allows for rotation in a
horizontal plane, while the elevation axis enables tilting in a vertical plane.
By operating on both axes, the solar panels can accurately follow the sun's
movement from sunrise to sunset, maximizing the absorption of solar energy.
Integrated sensors continually
monitor the sun's location, considering factors such as time, date, and
geographical coordinates. This information is then processed by a control
algorithm, which commands the actuators to reposition the solar panels
accordingly. The actuators, often based on motor-driven mounts or linear
actuators, ensure precise and smooth movement, maintaining optimal alignment
with the sun.
The advantages of a dual-axis solar
tracking system are numerous. Firstly, it significantly increases the overall
energy output of solar panels by up to 40% compared to fixed installations.
This enhanced efficiency ensures a higher return on investment for solar power
systems, making them more economically viable.
Moreover, by dynamically adjusting
the panel's tilt and orientation, the system minimizes the impact of shading,
dirt accumulation, and other environmental factors that can hinder output. This
proactive approach helps maintain consistent energy generation even in
challenging conditions.
Additionally, the project promotes
sustainability by utilizing renewable energy sources more effectively, reducing
reliance on fossil fuels and minimizing carbon emissions. It showcases the
ever-evolving advancements in renewable energy technology and highlights the
potential for a greener future.
3.2 Proposed System
The proposed dual-axis solar
tracking system project aims to revolutionize solar panel efficiency and expand
its capabilities even further. Building upon the existing system, this project
incorporates advanced technologies and innovative features to enhance solar
energy harnessing.
One key improvement in the proposed
system is the implementation of smart AI algorithms. By utilizing machine
learning and predictive modeling, the system can analyze historical data,
weather patterns, and solar irradiance forecasts to optimize solar panel
positioning in real time. This intelligent decision-making process enables the
system to proactively adjust panel angles for maximum sunlight absorption, even
under variable and uncertain conditions.
In addition to the azimuth and
elevation axes, the proposed system introduces a third axis: the roll axis.
This rotational movement allows the solar panels to track the sun's lateral
movement, optimizing their position for different times of the day and changing
solar angles. The roll axis adds an extra layer of flexibility and precision to
the panel orientation, ensuring utmost solar energy capture throughout the
entire day.
To
further enhance system efficiency, the proposed system incorporates various
energy-saving features. For instance, it employs high-efficiency solar cells
and anti-reflective coatings to minimize energy losses and maximize the
conversion of sunlight into electricity.
Additionally, the system
incorporates smart energy management techniques, such as intelligent battery
charging and grid synchronization, to efficiently store and distribute the
generated solar power.
Furthermore, the proposed system
focuses on user accessibility and ease of installation. It includes a
user-friendly interface that allows system monitoring, performance evaluation,
and remote control capabilities. Additionally, modular design and simplified
wiring systems simplify the installation process, making it more manageable and
time-effective.
With its advanced AI algorithms,
three-axis tracking capability, energy-saving features, and user-friendly
design, the proposed dual-axis solar tracking system project takes solar panel
efficiency to new heights. This system paves the way for improved renewable
energy utilization, increased cost-effectiveness, and a greener future powered
by sustainable solar energy.
CHAPTER 4
OBJECTIVES
The
venture was completed to fulfill two fundamental destinations:
- Design a framework
that tracks the sunlight based UV light for sun oriented boards in double
pivot.
- Prove that the
following in reality expands the proficiency impressively.
- The scope of
increment in proficiency is relied upon to be in the vicinity of 30 and 40
percent.
CHAPTER 5
METHODOLOGY
The dual-axis solar tracking system
project follows a systematic methodology to design, develop, and implement the
advanced tracking system. Here's an overview of the methodology involved:
- Project Planning: Define the project
objectives, requirements, and scope. Determine the available resources,
timeline, and budget. Plan the project phases, milestones, and
deliverables.
- Research and Analysis: Conduct thorough
research on existing solar tracking systems, technologies, and components.
Analyze the benefits, limitations, and feasibility of different tracking
system approaches. Evaluate the impact of solar panel orientation on
energy generation.
- System Design: Based on the
research findings, design the dual-axis solar tracking system. Determine
the system architecture, considering the azimuth, elevation, and roll
axes. Select appropriate sensors, actuators, and control mechanisms.
Layout the electrical and mechanical components.
- Sensor Integration: Integrate accurate
sun position sensors, such as GPS modules or solar tracking algorithms, to
continuously monitor the sun's position. Ensure the sensors provide
reliable data on time, date, latitude, and longitude.
- Actuator
Implementation:
Incorporate high-precision actuators capable of smoothly adjusting the
solar panel's azimuth, elevation, and roll angles. Ensure the actuators
can handle the load, are durable, and provide precise movements. Interface
the actuators with the control system.
- Control System
Development:
Develop a control algorithm using advanced techniques like machine
learning or predictive modeling. Implement software algorithms that
calculate the optimal sun-tracking angles based on real-time and
forecasted data. This algorithm should command the actuators to align the
solar panels accordingly.
- Prototype
Construction:
Build a functional prototype of the dual-axis solar tracking system based
on the design specifications. Assemble and integrate the components,
ensuring proper alignment and synchronization between sensors, actuators,
and control system.
- Testing and
Optimization:
Conduct rigorous testing of the tracking system prototype under various
environmental conditions. Measure and analyze the energy output,
efficiency, and accuracy of the system. Optimize the control algorithm and
system parameters to maximize energy yield and tracking precision.
- Performance
Evaluation:
Evaluate the performance of the dual-axis solar tracking system against
fixed solar panel installations. Compare energy generation, efficiency
gains, and return on investment. Conduct simulation or real-world tests to
validate system performance and reliability.
- Documentation and
Deployment:
Document the design, methodology, implementation details, and test
results. Prepare user manuals and documentation for system installation,
operation, and maintenance. If deemed successful, deploy the dual-axis
solar tracking system in relevant applications and environments.
- Continuous
Monitoring and Improvement: Monitor the system's performance
regularly, update software algorithms as needed, and perform periodic
maintenance. Seek feedback from users and stakeholders to identify areas
for improvement and innovation.
5.1 Scope of Work in the Project
The solar project was implemented
using two servo motors. The choice was informed by the fact that the motor is
fast, can sustain high torque, has precise rotation within limited angle and
does not produce any noise. The Arduino IDE was used for the coding. Kolkata
has coordinates of 22.5726°N, 88.3639°E and therefore the position of the sun
will vary in a significant way during the year. In the tropics, the sun
position varies considerably during certain seasons. There is the design of an
input stage that facilitates conversion of light into a voltage by the light
dependent resistors, LDRs.
There is comparison of the two
voltages, then the microcontroller uses the difference as the error. The servo
motor uses this error to rotate through a corresponding angle for the
adjustment of the position of the solar panel until such a time that the
voltage outputs in the LDRs are equal. The difference between the voltages of
the LDRs is received as analog readings.
Function
of the processor:
The analog readings are converted to integer values by ADC input ports which is
compared in order to get the difference value for motor movement.
The difference is transmitted to the
servo motor and it thus moves to ensure the two LDRs are an equal inclination.
This means they will be receiving the same amount of light, and the Solar panel
will receive the sunlight at 90°, (the plane of PV panel will make an angle 90°
with the Sun, and the perpendicular drawn on the plane makes an angle 0° with
the Sun, to ensure maximum illumination: Lambert’s cosine Law) The procedure is
repeated throughout the day. Tracker systems work on two simple principles
together. One being, the normal principle of incidence and reflection on which
our tracker works and the other is the principle on which the solar (PV) panel
works, which will produce electricity. Both these principles can be combined
and as a result of which it can produce nearly double the output that the panel
specifies normally.
CHAPTER 6
WORKING PRINCIPLE AND
BLOCK DIAGRAM
Ø Resistance
of LDR depends on intensity of the light and it varies according to it. The
higher is the intensity of light, lower will be the LDR resistance and due to this
the output voltage lowers and when the light intensity is low, higher will be
the LDR resistance and thus higher output voltage is obtained.
Ø A
potential divider circuit is used to get the output voltage from the sensors
(LDRs).The circuit is shown here.
Ø The LDR
senses the analog input in voltages between 0 to 5 volts and provides a digital
number at the output which generally ranges from 0 to1023.
Ø Now this
will give feedback to the microcontroller using the arduino software (IDE).
Ø The servo
motor position can be controlled by this mechanism which is discussed later in
the hardware model.
Ø The
tracker finally adjusts its position sensing the maximum intensity of light
falling perpendicular to it and stays there till it notices any further change.
Ø The
sensitivity of the LDR depends on point source of light. It hardly shows any
effect on diffuse lighting condition.
BASIC CIRCUIT DIAGRAM
An
overview of the required circuit for the Dual-axes solar tracker is shown here.
The 5V supply is fed from an USB 5V dc voltage source through ArduinoBoard.
Servo
Y :Rotates solar panel along Ydirection
MATHEMATICAL MODEL
MATHEMATICAL
EQUATIONS REQUIRED
INVERSE
SQUARE LAW
The illumination upon a surface
varies inversely as the square of the distance of the surface form the source.
Thus, if the illumination at a surface 1 metre from the source is I units, then
the illumination at 2 metres will be I/4, at 3 metres will be I/9 and so on.
In fact inverse square law operates
only when the light rays are from a point source and are incident normally upon
the surface.
Thus illumination in lamberts/m2 on
a normal plane= Candle power/ (Distance in metres)2
LAMBERT’S
COSINE LAW
The illumination received on a
surface is proportional to the cosine of the angle between the direction of the
incident light rays and normal to the surface at the point of incidence.
This is mainly due to the reduction
of the projected area as the angle of incidence increases.
Thus,
the equations are:
where,
Eθ
= illumination on horizontal plane
E
= illumination due to light normally
incident
θ = the angle of incidence
D
= distance from the surface
HARDWARE MODEL
BLOCK
DIAGRAM OF THE SOLAR TRACKER:
Shaft
EXPLANATION
OF THE BLOCK DIAGRAM:
As we see in the block diagram,
there are three Light Dependent Resistors (LDRs) which are placed on a common
plate with solar panel. Light from a source strikes on them by different
amounts. Due to their inherent property of decreasing resistance with
increasing incident light intensity, i.e. photoconductivity, the value of
resistances of all the LDRs is not always same.
Each LDR sends equivalent signal of
their respective resistance value to the Microcontroller which is configured by
required programming logic. The values are compared with each other by
considering a particular LDR value as reference.
One of the two dc servo motors is
mechanically attached with the driving axle of the other one so that the former
will move with rotation of the axle of latter one. The axle of the former servo
motor is used to drive a solar panel. These two-servo motors are arranged in
such a way that the solar panel can move along X-axis as well as Y-axis.
The microcontroller sends
appropriate signals to the servo motors based on the input signals received
from the LDRs. One servo motor is used for tracking along x-axis and the other
is for y-axis tracking.
In
this way the solar tracking system is designed.
ARDUINO
UNO
The Arduino Uno is a microcontroller
board based on the ATmega328. Arduino is an open- source, prototyping platform
and its simplicity makes it ideal for hobbyists to use as well as
professionals. The Arduino Uno has 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. It contains
everything needed to support the microcontroller; simply connect it to a
computer with a USB cable or power it with a AC-to- DC adapter or battery to get
started.
The Arduino Uno differs from all
preceding boards in that it does not use the FTDI USB-to- serial driver chip.
Instead, it features the Atmega8U2 microcontroller chip programmed as a
USB-to-serial converter.
"Uno" means one in Italian
and is named to mark the upcoming release of Arduino 1.0. The Arduino Uno and
version 1.0 will be the reference versions of Arduno, moving forward. The Uno
is the latest in a series of USB Arduino boards, and the reference model for
the Arduino platform.
THE
ATMEGA328P-PU ATMEL 8 BIT 32K AVR MICROCONTROLLER
The Atmel®picoPower®ATmega328/P is a
low-power CMOS 8-bit microcontroller based on the AVR® enhanced RISC
architecture.
PIN
DIAGRAM:
PIN
Layout of ATmega328p is shown below:
AVR
CPU CORE ARCHITECTURE
The main function of the CPU core is
to ensure correct program execution. The CPU must therefore be able to access
memories, perform calculations, control peripherals, and handle interrupts.
Flash, EEPROM, and SRAM are all
integrated onto a single chip, removing the need for external memory in most
applications. Some devices have a parallel external bus option to allow adding
additional data memory or memory-mapped devices. Almost all devices (except the
smallest Tiny AVR chips) have serial interfaces, which can be used to connect
larger serial EEPROMs or flash chips.
BLOCK
DIAGRAM OF AVR ARCHITECTURE
CPU
The CPU of the AVR microcontroller
is same but so simple like the one in a computer. The main purpose of the CPU
is to confirm correct program performance. Therefore, the CPU must be able to
access perform calculations, memories, control peripherals & handle
interrupts. The CPUsofAtmel’s8-bitand32-bit AVR are based on an innovative
“Harvard architecture” thus every IC has two buses namely one instruction bus
and data bus. The CPU reads executable instructions in instruction bus, where
in the data bus, is toread or writes the corresponding data. The CPU core of
the AVR consists of the ALU, General Purpose Registers, Program Counter,
Instruction Register, Instruction Decoder, Status Register and Stack Pointer
Flash
Program Memory
The program of the AVR
microcontroller is stored in non-volatile programmable Flash program memory
which is just similar to the flash storage in your SDC ardor Mp3Player.The
Flash program memory is separated into two units. The first unit is the
Application Flash section. It is where the program of the AVR is stored. The
second section is named as the Boot Flash section and can be fixed to perform
directly when the device is powered up. One significant fact to note is that
the microcontrollers Flash program memory has a resolution of at least 10,000
writes/erase cycles.
SRAM
The SRAM (Static Random Access
Memory) of the AVR microcontroller is just like computer RAM. While the
registers are used to execute calculations, the SRAM is used to supply data
through the runtime. This volatile memory is prearranged in 8-bitregisters.
EEPROM
The term EEPROM stands for
Electrically Erasable Read-Only Memory is like a nonvolatile memory, but you
can’t run a program from it, but it is used as longtime storage. The EEPROM
doesn’t get removed when the IC loses power. It’s a great place for storing
data like device parameters and configuration of the system at run time so that
it can continue between resets of the application processor. One significant
fact to note is that the EEPROM memory of the AVR has a limited lifetime of
100,000writes/EEPROMpage–reads are limitless. Keep this in Mind in your
application and try to keep writing to a minimum, so that you only write the
small amount of info required for your application every time you update the
EEPROM.
Digital
I/O Modules
The digital I/O modules let digital
communication or logic communication with the AVR microcontroller and the
exterior world. Communication signals are that of TTL/CMOS logic.
Analog
I/O Modules
Analog I/O modules are used to input
or output analog information from or to the exterior world. These modules
comprise analog comparators and analog-to-digital converters (ADC).
Interrupt
Unit
Interrupts have enabled the
microcontroller to monitor particular events in the background while performing
and application program & respond to the occurrence if required pausing the
unique program. This is all synchronized by the interrupt Unit.
Timer
Most AVR microcontrollers have at
least one Timer or Counter module which is used to achieve timing or counting
operations in the microcontroller. These comprise time stamping, counting
events, measuring intervals, etc.
LDR
- It is a
photo-resistor is a device whose resistivity is a function of the incident
electromagnetic radiation. Hence, they are light sensitive devices. They
are also called as photo conductors, photo conductive cells or simply photocells.
- They are made up of
semiconductor materials having high resistance.
- LDR works on the
principle of photoconductivity.
Photo conductivity is an optical
phenomenon in which the material’s conductivity is increased when light is
absorbed by the material.
The most common type of LDR has a
resistance that falls with an increase in the light intensity falling upon the
device (as shown in the image above). The resistance of an LDR may typically
have the following resistances:
Daylight = 5000Ω
Dark = 20000000Ω
Therefore, it is seen that there is
a large variation between these figures. If this variation is plotted on a
graph, something similar to the figure given below can be seen.
SERVO
MOTOR
ADC servo motor consists of a small DC
motor, feed back potentiometer, gearbox, motor drive electronic circuit and
electronic feedback control loop. It is more or less similar to the normal DC
motor.
The stator of the motor consists of
a cylindrical frame and the magnet is attached to the inside of the frame.
A brush is built with an armature
coil that supplies the current to the commutator. At the back of the shaft, a
detector is built into the rotor in order to detect the rotation speed. With
this construction, it is simple to design a controller using simple circuitry
because the torque is proportional to the amount of current flow through the
armature
ADC
CONCEPT IN ARDUINO UNO
Arduino uno board has 6 ADC input
ports. Among those any one or all of them can be used as inputs for analog
voltage. The Arduino Uno ADC is of 10 bit resolution (so the integer
valuesfrom(0-(2^10)1023)). This means that it will
mapinputvoltagesbetween0and5volts into integer values between 0 and 1023. So,
for every (5/1024= 4.9mV) perunit.
The UNO ADC channels have a default
reference value of 5V. This means we can give a maximum input voltage of 5V for
ADC conversion at any input channel. Since some sensors provide voltages from
0-2.5V, with a 5V reference we get lesser accuracy, so we have a instruction
that enables us to change this reference value. So for changing the reference
value we have(“analogReference();”).
As default we get the maximum board
ADC resolution which is 10bits, this resolution canbe changed by using
instruction(“analogReadResolution(bits);”)
SOFTWARE PROGRAM MODEL
PROGRAMMING
CODE:
#include
<Servo.h> Servo myservo; Servo ourservo;
int
posx = 90; // initial position is top
int
posy = 90;
int
sens1 = A0; // (x,0) LDR int sens2 = A1; // (0,0) LDR int sens3 = A2; // (0,y)
LDR int tolerance = 2;
void
setup()
{
myservo.attach(9);
// pin9 ourservo.attach(10); // pin10 pinMode(sens1, INPUT); pinMode(sens2,
INPUT); pinMode(sens3, INPUT); myservo.write(posx); delay(1000); // buffer
delay ourservo.write(posy); delay(1000);
void
loop()
{
//For
First Axis
int
val1 = analogRead(sens1); // read sensor1
int
val2 = analogRead(sens2); // read sensor2
if((abs(val1
- val2) <= tolerance) || (abs(val2 - val1) <= tolerance))
{
//do
nothing
}
else
{
if(val1
>val2)
{
posx
= --posx;
}
if(val1
<val2)
{
posx
= ++posx;
}
}
myservo.write(posx);
// write the position to servo
delay(50);
int
val3 = analogRead(sens3);//read sensor 3 val2 = analogRead(sens2); // read
sensor
2
val3 = analogRead(sens3); // read sensor 3
//For
Second Axis
if((abs(val2
- val3) <= tolerance) || (abs(val3 - val2) <= tolerance))
{
//do
nothing
}
else
{
if(val2
> val3)
{
posy
= ++posy;
}
if(val2
<val3)
{
posy
=--posy;
}
}
if(posy
> 150) { posy = 150; } if(posy < 30) { posy = 30; } ourservo.write(posy);
delay(50);
}
DESCRIPTION
OF THE SOFTWARE PROGRAM
STEPS:
- First of all, both
the servos are declared and object is created to control the servo motors.
- The variables posx and
posy are used to store the reference servo positions.
- The ADC input pins
for LDRs are selected for dual direction movement and one for reference.
- A tolerance or a constant
value is selected to establish the working of the motors.
- The servos are
attached on digital pins to the servo object.
- The required analog
pins are selected as input using pin Mode (pin, mode)
- The servos are sets
to mid-point or original position with a1000ms or 1 sec delay to catch up
with the user.
- Three variables are
chosen to read the analog values and map it into integers value between 0 and
1023.
- If the difference
between the two variables is less than the tolerance value then it will
stays to its or original location else it shows movement towards the
direction of maximum intensity of light by incrementing or decrementing
the values of posx and posy.
- The position is
then written to servo and the loop repeats till it encounter any changes
in the values of input greater than the minimum tolerance.
- If the position
becomes greater than 150˚then position will be set to 150˚only and if the
position of the motor is less than 30˚then it would be kept at 30˚only as
the lower and upper limit angles are chosen to be 30˚and150˚respectively
LDR
PROGRAM AND GRAPH
void
setup()
{
Serial.begin(9600);
}
void
loop()
{
int
sensorValue = analogRead(A0); Serial.println(sensorValue); delay(10);
}
CODE
RELATING ANALOG TO DIGITAL CONVERSION
In the program below, the very first
thing that you do will in the setup function is to begin serial communications,
at 9600 bits of data per second, between your board and your computer with the
line:
Serial.begin(9600);
Next,
in the main loop of your code, you need to establish a variable to store the
resistance value (which will be between 0 and 1023, perfect for an int
datatype) coming in from your potentiometer:
int
sensorValue = analogRead(A0);
To
change the values from 0-1023 to arrange that corresponds to the voltage the pin
is reading, you'll need to create another variable, a float, and do a little
math. To scale the numbers between 0.0 and 5.0, divide 5.0 by 1023.0 and
multiply that by sensorValue:
float
voltage= sensorValue * (5.0 / 1023.0);
Finally,
you need to print this information to your serial window as. You can do this
with the command Serial.println() in your last line of code:
Serial.println(voltage)
Now,
when you open your Serial Monitor in the Arduino IDE (by clicking on the icon
on the right side of the top green bar or pressing Ctrl+Shift+M), you should
see a steady stream of numbers ranging from 0.0 - 5.0. As you turn the pot, the
values will change, corresponding to the voltage coming into pinA0.
ABOUT
SOLAR PANEL AND CONNECTED LOAD
- Solar panel is
placed at the top and connected to a load directly. The load may a led or
a voltmeter which could be connected to get the exact voltage which
depends on the intensity of light falling on the panel and the position of
the tracker.
- Concentrated solar photovoltaics’
and have optics that directly accept sunlight, so solar trackers must be angled
correctly to collect energy. All concentrated solar systems have trackers
because the systems do not produce energy unless directed correctly toward
the sun.
- The solar panel is
just a mere device to accept the light radiation which is purely
controlled by LDR sensors and the load connected depends upon the rating
of the panel used.
DUAL
AXIS MOVEMENT OF SOLAR TRACKER
- The dual axis solar
tracker is device which senses the light and positions towards the maximum
intensity of light. It is made in such away to track the light coming from
any direction.
- To simulate the
general scenario of the Sun’s movement, the total coverage of the movement
of the tracker is considered as 120˚ in both the directions.
- The initial
position of both the servo motors are chosen at 90˚i.e, for east-west
servo motor as well as for north-south servomotor.
- Thepositionofthetrackerascendsordescendsonlywhenthethresholdvalueisabove
the tolerance limit.
Approximation
of power output (red line) compared to maximum output (blueline) for a fix
mounted solar module:
BENEFITS
AND DEMERITS OF SOLAR ENERGY
There are several benefits that
solar energy has and which make it favourable for many uses.
Benefits:
- Solar energy is a
clean and renewable energy source.
- Once a solar panel
is installed, the energy is produced at reduced costs.
- Whereas the
reserves of oil of the world are estimated to be depleted in future, solar
energy will last forever.
- It is pollution
free.
- Solar cells are
free of any noise. On the other hand, various machines used for pumping
oil or for power generation are noisy.
- Once solar cells
have been installed and running, minimal maintenance is required. Some
solar panels have no moving parts, making them to last even longer with no
maintenance.
- On average, it is
possible to have a high return on investment because of the free energy
solar panels produce.
- Solar energy can be
used in very remote areas where extension of the electricity power grid is
costly.
Demerits:
- Solar panels can be
costly to install resulting in a time lag of many years for savings on
energy bills to match initial investments.
- Generation of
electricity from solar is dependent on the country’s exposure to sunlight.
That means some countries are slightly disadvantaged.
- Solar power
stations do not match the power output of conventional power stations of
similar size. Furthermore, they may be expensive to build.
- Solar power is used
for charging large batteries so that solar powered devices can be used in
the night. The batteries used can be large and heavy, taking up plenty of
space and needing frequent replacement.
FINALLY,
As the merits are more than the
demerits, the use of solar power is considered as a clean and viable source of
energy. The various limitations can be reduced through various ways.
OBSERVATIONS
AND RESULT
WHAT
WE HAVE OBSERVED....
In this Dual Axis Solar Tracker,
when source light falls on the panel, the panel adjusts its position according
to maximum intensity of light falling perpendicular to it. The objective of the project is completed.
This was achieved through using light sensors that are able to detect the
amount of sunlight that reaches the solar panel. The values obtained by the
LDRs are compared and if there is any significant difference, there is
actuation of the panel using a servo motor to the point where it is almost
perpendicular to the rays of the sun.
Thiswasachievedusingasystemwiththreestagesorsubsystems.Eachstagehasitsownrole.
The stages were;
- An input stage that
was responsible for converting incident light to a voltage.
- A control stage
that was responsible for controlling actuation and decision making.
- A driver stage with
the servo motor. It was responsible for actual movement of the panel.
The input stage is designed with a
voltage divider circuit so that it gives desired range of illumination for
bright illumination conditions or when there is dim lighting. The potentiometer
was adjusted to cater for such changes. The LDRs were found to be most suitable
for this project because their resistance varies with light. They are readily
available and are cost effective. Temperature sensors for instance would be
costly.
The control stage has a
microcontroller that receives voltages from the LDRs and determines the action
to be performed. The microcontroller is programmed to ensure it sends a signal
to the servo motor that moves in accordance with the generated error.
The final stage was the driving
circuitry that consisted mainly of the servo motor. The servo motor had enough
torque to drive the panel. Servo motors are noise free and are affordable,
making them the best choice for the project.
CHAPTER 7
CONCLUSION
In this 21st century, as we build up
our technology, population & growth, the energy consumption per capita
increases exponentially, as well as our energy resources (e.g. fossils fuels)
decrease rapidly. So, for sustainable development, we have to think alternative
methods (utilization of renewable energy sources) in order to fulfill our energy
demand.
In this project, Dual Axis Solar
Tracker, we’ve developed a demo model of solar tracker to track the maximum
intensity point of light source so that the voltage given at that point by the
solar panel is maximum. After a lot of trial and errors we’ve successfully
completed our project and we are proud to invest some effort for our society.
Now, like every other experiment, this project has couple of imperfections.
i.
Our panel senses the light in a sensing zone,
beyond which it fails to respond.
ii.
If multiple sources of light (i.e. diffused
light source) appear on panel, it calculates the vector sum of light sources
& moves the panel in that point.
This project was implemented with
minimal resources. The circuitry was kept simple, understandable and user
friendly.
SPECIFICATIONS OF THE
HARDWARE REQUIREMENT
FEATURES
OF ARDUINOUNO
- Microcontroller:
ATMEGA328P
The Atmel®picoPower®ATmega328/P is a
low-power CMOS 8-bitmicrocontroller based on the AVR® enhanced RISC
architecture.
FEATURES:
High
Performance, Low Power Atmel®AVR® 8-Bit Microcontroller Family
- Advanced RISC
Architecture
- 131
Powerful Instructions
- Most
Single Clock Cycle Execution
- 32
x 8 General Purpose Working Registers
- Fully
Static Operation
- Up
to 20 MIPS Throughput at20MHz
- On-chip
2-cycleMultiplier
- High Endurance
Non-volatile MemorySegments
- 32KBytes
of In-System Self-Programmable Flash program Memory
- 1KBytesEEPROM
- 2KBytes
Internal SRAM
- Write/Erase
Cycles: 10,000 Flash/100,000EEPROM
- Data
Retention: 20 years at 85°C/100 years at25°C(1)
- Optional
Boot Code Section with Independent LockBits
- In-System
Programming by On-chip BootProgram
- True
Read-While-WriteOperation
- Programming
Lock for SoftwareSecurity
- Operating
Voltage:5v
- Input Voltage
(recommended):7-12V
- Input Voltage
(limits):6-20V
- Digital I/O Pins:
14 (of which 6 provide PWMoutput)
- Analog Input Pins:6
- DC Current per I/O
Pin: 40mA
- DC Current for 3.3V
Pin: 50mA
- Flash Memory: 32 KB
of which 0.5 KB used bybootloader
- SRAM: 2
KB(ATmega328)
- EEPROM: 1
KB(ATmega328)
- Clock Speed: 16MHz
SOLARPANEL
- Maximum Voltage:
4volts (underload)
- Maximum Voltage:
4.8volts (noload)
- Rated Current:100mA
- Dimension: 6 cm (L) x 6 cm (W) x 0.25 cm(t)
- Maximum
Wattage:0.5W
LIGHT
DEPENDEN TRESISTOR
Photoresistor
5mm GL5516 LDR Photo Resistors Light-Dependent Resistor Model: GL5516
- Size: 5mm x2mm
- Maximum Voltage:
150 VoltDC
- Maximum
Wattage:90mW
- Operating
Temperature: (-30 to+70)°C
- Spectral Peak:540nm
- Light Resistance
(at 10 Lux): 5-10kΩ
- Dark Resistance:
0.5MΩ
- Response time: 20ms
(Rise), 30ms(Down)
- Resistance
Illumination: 4
AVENUES
FOR FURTHER WORK
With the available time and
resources, the objective of the project was met. The project is able to be
implemented on a much larger scale. For future projects, one may consider the
use of more efficient sensors, which should also be cost effective and consume
little power.
This would further enhance
efficiency while reducing costs. If there is the possibility of further
reducing the cost of this project, it would help a great deal. This is because
whether or not such projects are embraced is dependent on how cheap they can
be. Shading has adverse effects on the operation of solar panels. Shading of a
single cell will have an effect on the entire panel because the cells are usually
connected in series. With shading therefore, the tracking system will not be
able to improve efficiency as is required.
REFERENCES
[1]
Solar Tracking Hardware and
Software by Gerro JPrinsloo
[2]
Design and Implementation of a Sun
Tracker with a Dual-Axis Single Motor “Jing-Min
Wang and Chia-LiangLu’’
[3]
Sensors and Transducers...Second
Edition...’’D.Patranabis”
[4] Atmel
ATmega48A/PA/88A/PA/168A/PA/328/P-datasheet
[5]
Utilisation of Electrical Power.
Author, Er. R. K.Rajput.
[6]
Arduino Programming Book. Author,
Brian W.Evans
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