Dual Axis Solar Tracking System - A PROJECT
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
FLOW CHART
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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