mini project report_artificial sunflower

Dept. of EEE i CMRIT, BANGALORE

PROJECT REPORT on

Artificial Sunflower (A survey on commercial solar trackers & preliminary implementation steps for

an indigenous model)

BACHELORS OF ENGINEERING

in

ELECTRICAL AND ELECTRONICS ENGINEERING

Visveswaraya Technological University

Submitted by

ISHAN GAUTAM (1CR12EE043)

DEEP SIDDHARTH (1CR12EE029)

DIBYASHA MAHAPATRA (1CR12EE033)

GURUPRIYA RAJENDRAN M V (1CR12EE042)

DILIP B S (1CR12EE034)

Under the guidance of

Dr. Chaitanya Lekshmi Indira Department of Chemistry

Dept. of EEE ii CMRIT, BANGALORE

Department of Electrical Engineering

C.M.R Institute of Technology

BANGALORE-560037

CERTIFICATE

Certified that the project work entitled “ARTIFICIAL SUNFLOWER” is

an original work carried out by Ishan Gautam, Deep Siddharth, Dibyasha

Mahapatra, Gurupriya Rajendran M V and Dilip B S in partial fulfillment

of 6th semester Bachelor of Engineering in Electrical and Electronics

Engineering of CMR Institute of Technology, under the Visvesvaraya

Technological University, Belgaum under the guidance of Dr. Chaitanya

Lekshmi Indira during the year 2014-2015. The Project report has been

approved as it satisfies the academic requirements in respect of project

work prescribed for the Bachelor of Engineering degree.

Signature of Guide Signature of HOD

Dept. of EEE iii CMRIT, BANGALORE

Contents

Chapter 1. Introduction....…………………………………..1

1.1. Objectives....……………………………………………1

1.2. Achievements and Boundaries ………………………...2

Chapter 2. Background ……………………………………..3

2.1. Sources of energy ……………………………………...3

2.2. Global warming and climate change …………………..3

2.3. Solar energy ....…………………………………………4

2.4. Efficiency ………………………………………………5

Chapter 3. Efficiency of PV panel ………………………….7

3.1. Parameters affecting performance ……………………..7

3.2. Methods to increase efficiency ………………………...9

Chapter 4. Solar tracker …………………………………...12

4.1. Hardware ……………………………………………...12

4.2. Software and programming …………………………...15

Chapter 5. Outcomes and achievements ………………......21

5.1. Implementation in large scale …………………………22

5.2. Conclusion …………………………………………….25

Chapter 6. References ………………………………………26

Dept. of EEE 1 CMRIT, BANGALORE

1. Introduction

Solar energy is the cleanest and most abundant source of energy available. It can be

harnessed like any other type of energy and used to create electricity. As of now

many vehicles, instruments and machines harness solar energy to function. One of

the efficient and most commonly used methods to harness solar energy is by using

solar panels made up of photovoltaic cells (semiconductor in nature). Si based

photovoltaic cells are the most widely used type and largely put into commercial

usages.

Generally we assess the performance of any system by its efficiency, higher the

efficiency better the system works. When it comes to conversion of solar energy into

other useful forms of energy, efficiency is still not largely a plus point. The typical

solar panel setups installed so far can achieve up to 15% efficiency which is very

less. There are, however methods of increasing the efficiency of solar panel system.

This project concentrates on one such method involving an apparatus called ‘Solar

tracker’. A solar tracker is a device which holds the solar panel, orienting it towards

the sun as the sun moves throughout the day, all through the year. Solar tracker

increases the efficiency of the solar panels by enabling them to face directly the sun

throughout the daylight time period and thus can generate maximum electricity. Use

of solar trackers increases the amount of sunlight received by the solar panel during

the day.

By surveying existing techniques and using a suitable one, we target to build a dual-

axis solar tracker with minimum cost that orients any payload towards the sun

throughout the day and year. As the features of this solar tracker are very similar to

that of a sunflower which faces the sun throughout the day, we have titled the project

as artificial sunflower.

1.1 Project Objectives

To summarize, the project objectives are:

Literature survey of current and existing technologies involving solar energy

and solar trackers and materials for antireflection coating on solar panels.

To collect necessary data needed to evaluate the efficiency graph of solar

panels with and without solar tracker.

Designing and building a dual axis solar tracker using Arduino open source

hardware technology. Reduce the expenses by using power saving methods

and increased accuracy.


1.2 Achievements and Boundaries

The main objective of the project ‘Artificial sunflower’ is to successfully build a

dual axis solar tracker with less expenses and power saving methods. This

was achieved by using a 8-bit microcontroller ATmega328 which has power

saving mode that hibernates the entire tracker when not needed, i.e. during

night time and even during rain or other weather conditions.

At the time of the conception of the project, the aim was to record data of

solar panel exposed to sunlight throughout the day with the help of the solar

tracker we built. This way we would have the comparison between the

efficiency achieved by stationary solar panels and the solar panels using solar

trackers. This however could not be completed to limited time available.


2 Background

In the present world of increasing population the demands for settlements and other

facilities increase exponentially. To meet these demands, energy requirements also

increase. The increase in energy production has its own side effects /drawbacks.

2.1 Sources of energy Two broadly classified sources of energy are renewable energy sources and non-

renewable energy sources. Renewable energy is generally defined as energy that

comes from resources which are naturally replenished on a human timescale such

as sunlight, wind, rain, tides, waves, and geothermal heat. Non-renewable energies

are those that do not self-sustain naturally. Examples of non-renewable energies are

coal, oil and natural gas.

2.2 Global warming and Climate change

Unlike renewable energy sources like wind, water and sun--most of which are

converted to power cleanly--the conversion of fossil fuels to usable energy can result

in harmful emissions and its collection can disrupt local wildlife.

The processing of fossil fuels emits harmful greenhouse gases into the air. These

gases, primarily carbon dioxide, damage the ozone layer which protects us from the

sun's radiation. The air pollution also negatively affects our respiratory health

Acid rain is created by the emission of sulfur and other chemicals into the

atmosphere, often from the conversion of fossil fuels into electricity. It is corrosive to

machinery and can disrupt local ecosystems. Harmful ash is stored in solid waste

containment areas which are prone to rupturing and causing havoc in the

surrounding areas. Totally we can term these chain of events as global warming.

Global Warming is the increase of Earth's average surface temperature due to effect

of greenhouse gases, such as carbon dioxide emissions from burning fossil fuels or

from deforestation, which trap heat that would otherwise escape from Earth. This is a

type of greenhouse effect. The most significant greenhouse gas is actually water

vapor, not something produced directly by humankind in significant amounts.


Greenhouse gas emissions recorded at international energy agency over years

However, even slight increases in atmospheric levels of carbon dioxide (CO2) can

cause a substantial increase in temperature.

The figure above shows a statistics graph of increase in the emission of carbon

dioxide (CO2) recorded over a span of 20 years from 1990 to 2010, recent increase

in automobiles and increased energy demands, the rate at which fossil fuels are

processed is high. This in turn increases the carbon dioxide (CO2) emissions.

Most of the generators are run by a steam turbine. Those steam turbines are

indirectly increasing the amount of water vapor, added to that are the emission of

greenhouse gases by fossil fuel.

2.3 Solar energy

The most abundant renewable source of energy that we have available is solar

energy. We receive solar energy in form of heat and light from sun, the star of our

solar system. Solar energy can be converted to useful form of energy using solar

panels. Solar panels are made up of photovoltaic cells which are semi-conductive in

nature.


Photovoltaics (PVs) are arrays of cells containing a solar photovoltaic material that

converts solar radiation into direct current electricity. Solar cells produce direct

current (DC) electricity from sunlight, which can be used to power bulb/equipment or

to recharge a battery, however, for grid connected power generation; an inverter is

required to convert the DC to alternating current (AC).

A number of solar cells electrically connected to each other and mounted in a

support structure or frame is called a photovoltaic module. Multiple modules can be

wired together to form an array. In general, the larger the area of a module or array,

the more electricity that will be produced.

The most common PV devices use a single junction, or interface, to create an electric field within a semiconductor such as a PV cell. In a single-junction PV cell, only photons whose energy is equal to or greater than the band gap of the cell material can free an electron for an electric circuit. In other words, the photovoltaic response of single-junction cells is limited to the portion of the sun's spectrum whose energy is above the band gap of the absorbing material, and lower-energy photons are not used. One way to get around this limitation is to use two (or more) different cells, with more than one band gap and more than one junction, to generate a voltage. These are referred to as "multijunction" cells (also called "cascade" or "tandem" cells). Multijunction devices can achieve a higher total conversion efficiency because they can convert more of the energy spectrum of light to electricity.

2.4 Efficiency

Efficiency of any system is the ratio of the obtained output to the rated input. In case

of solar panel, the energy conversion efficiency of a solar cell is the percentage of

the solar energy that is converted into useful form of energy (electrical energy). One

of the basic formula to calculate the energy conversion efficiency is

where,

Pm represents maximum power output of solar cell in watts

G represents the input light in W/m^2

Ac represents the surface area of the solar cell in m^2.


Most solar panels are around 11-15% efficient. The efficiency rating measures what

percentage of sunlight hitting a panel gets turned into electricity that you can use.

The higher the efficiency, the less surface area you’ll need in your solar panels.

We can see that the efficiency of conventional solar panels is very less. A survey

was conducted which shows us that the solar panels do not meet the expected

requirements when it comes to efficient conversion,

The above graph is a comparison between flat plate solar panel and evacuated tube

solar panel against the reference of annual demand of energy. We can see that both

type of solar panels do not meet the annual demand required. The conversion

efficiency is less due to this. The efficiency of a solar panel is affected by many

factors which are discussed in next chapter.


3 Efficiency of a photovoltaic cell

As discussed in the previous chapter, even though theoretically the expected

efficiency is around 90%, the actual efficiency is around 15%. The Fraunhofer

Institute for Solar Energy Systems ISE, Soitec, CEA-Leti and the Helmholtz Center

Berlin jointly hold the record for achieving highest solar energy conversion efficiency

of about 44.7%.

Various types of solar panels give different range of efficiency as shown,

Hence we can see that the average efficiency lies under 15%, this is due to the

various factors affecting the performance of the solar panel.

3.1 Parameters affecting performance of PV cells

Considering the size and efficiency some other factors affect the performance i.e.

how the solar panel generates. Some of them are given below,

Effects of temperature: The output of a solar cell, and therefore a solar panel, is

affected by its temperature. The photons when they hit the solar panel hey bump into

an electron and give it the energy they were carrying. When this happens the

electron goes from a low-energy state to a high-energy one. The solar cell is then


designed to extract this electron in the high energy state and run it through an

electrical circuit to use up this extra energy that the electron has. Sometimes though

this high-energy electron will bump into other atoms in the solar cell before it

manages to get out, and the electron loses this extra energy which turns into heat

rather than electricity. As a result the power output will be reduced by between

0.25% (amorphous cells) and 0.5% (most crystalline cells) for each degree C of

temperature rise.

Panel temperatures in the summer in warm climates can easily reach 50 degree C

resulting in a 12% reduction in output compared to the rated output at 25 degree C.

This reduction if efficiency maybe important if there is a high demand for electricity in

summer.

Panel Orientation and pitch: Photovoltaic panels collect solar radiation directly from

the sun, from the sky, and from sunlight reflected off the ground or area surrounding

the PV panel. Orienting the PV panel in a direction and tilt to maximize its exposure

to direct sunlight will optimize the collection efficiency. The panel will collect solar

radiation most efficiently when the sun's rays are perpendicular to the panel's

surface. The angle of the sun varies throughout the year as shown in the figure

below. Therefore, the optimal tilt angle for a PV panel in the winter will differ from the

optimal tilt angle for the summer. This angle will also vary by latitude.

Range of midday sun angles at 12.97° south latitude(Bangalore)

The main step in determining optimal PV panel orientation and tilt angle is to review

the site where the PV lighting system will be installed. Trees, large buildings, or other

structures or obstructions surrounding the site might cast shadows onto a tilted PV

panel at various times of day or during winter months when the sun is at a low angle

in the sky. Therefore, it may be best to orient the PV panels horizontally to face the

sky directly. This may allow the panels to collect the maximum amount of solar

radiation with the least obstruction.


Shade: Shade can be the enemy of solar power. The way solar is designed even a

little shade on one panel can shut down solar production on all the other panels.

Solar cells are connected in series, and will operate at the current level of the

weakest cell, if one solar cell is shaded it will adversely influence the output of all

other cells. When deciding on a location for your solar panels do a shading analysis,

make sure no shadows will fall on the solar panel array during peak sunlight hours.

This may mean trimming a few trees.

Front surface soiling: Solar cells cannot absorb light as effectively when the surface

of the solar panels are covered with dirt or pigeon droppings, which doesn’t get

washed by the rain. Making frequent physical inspections and spraying water on the

modules can help reduce the problem.

3.2 Methods of increasing efficiency

There are various methods of increasing the efficiency of solar panel. Among those

in this project we choose to concentrate on these two methods,

a) By using anti-reflective coating

b) By using solar tracker

Anti-reflective coating

Selection of the Anti- reflective coating:

For a solar panel to be used efficiently, the maximum sunlight falling on it should be

absorbed into it. A regular solar panel is made up of silicon material. So usually the

sunlight rays travel from the air to the panel made up of silicon. But when using air

there is some amount of the light which gets reflected. So we can use an anti-

reflective coating made of glass which reduces the amount of light reflected back.

The following calculations show how the reflection is reduced theoretically,

We know that the refractive indices of air (n0) =1, glass (n1) =1.5 and that of silicon

(n2) = 3.44.

And we use the wavelength (λ) as 0.6µm since that’s the range of sunlight which is

more abundant

i) When the solar panel is used without anti – reflective coating:


Let us represent the refractive index of the anti-reflecting material as nf.

Consider the surrounding medium to be just air since we are not using an anti-

reflective coating

We can calculate the value of nf =√n𝟎 ∗ n1

Therefore by calculations, nf =1.8547

The thickness (d) of the anti-reflective can be determined as

d= λ/(4* nf)

By calculations, d=0.08 μm.

The amount to light which is reflected is given by the following formula,

Reflected Light(R) =r1^2+r2^2+2*r1*r2*cos2θ

1+r1^2*r2^2+2*r1*r2*cos2θ

Where r1= (n0- nf)/(n0+ nf)

r2= (nf – n1)/ (nf + n1)

θ= (2*π*nf*d)/λ

Therefore by calculations for this case,

r1=-0.3

r2=0.3

θ=1.57

R=0.000326

ii) When using an anti-reflective coating:

So we have glass as anti-reflective material

Same formulas are used, the values are as follows:

nf=2.27

d=0.066μm

r1=-0.204

r2=0.205

θ=1.57

R=0.00013


Therefore by the calculations it’s clear that the amount of light reflected is reduced

with glass as an anti-reflecting material. As the amount of reflected light reduces, the

amount of light absorbed by the solar panel increases. Hence more amount of

sunlight is getting converted using the same solar panel of same surface area. The

maximum power output is increased significantly by introducing anti-reflective

coating.

Even though as shown by our calculations, on addition of glass over the silicon

based solar cell, the amount of there is still some amount of energy that is being lost

which in turn directly effects the efficiency of the solar cell. In order to improve the

efficiency of the solar panel, by decreasing the energy lost, we have to put an anti-

reflective coating over the glass.

Anti-reflective coating is an optical thin film material. Some of the materials that

proved to be useful to this respect are silicon dioxide, indium-tin oxide and titanium

dioxide. Each of these have a refractive index of around 1.05, which is lower than

glass and can cause a possible total internal reflection which could improve the

efficiency further.

It is been shown that silicon dioxide and titanium dioxide coating on the glass of the

solar panel increases the cell efficiency by 3-4 %. Sono Tek corporations have

already started using an ultrasonic spray system designed to provide these coating

on the panels. So by using an anti-reflective coating, we can increase the efficiency

of the solar panel.


4 Solar tracker

The main objective of this project artificial sunflower is to design and build a solar

tracker which automatically orients itself towards the sun such that the payload it lifts

get as much as sunlight as possible throughout the day and year. We are using

existing technology and electronic components to build a circuit which makes the sun

tracking possible. Our solar tracker is made of light sensors which is connected to

programmable servo motors. These servo take the action as instructed and rotate

the panel 180º to adjust towards sunlight.

4.1 Hardware

The solar tracker is built using,

An 8-bit microcontroller ATmega328

4 light dependant resistors

2 servo motors-9v dc

An open source electronic platform-in this case Arduino.

Passive electronic components such as resistors, potentiometers etc.

The diagram below shows the block diagram of the tracker


The main circuit is the control circuit block which contains electrical circuit consisting

of passive resistive elements, the light dependant resistors are the input devices

which take in the sunlight to determine the position and orientation of the entire

tracker. In our project the LDRs are interfaced with the Arduino board through the

analog pins present on the Arduino used. We obtain the analog input from the LDRs

through the board and find the most suitable position for the solar panel such that the

maximum amount of light falls on the panel. In accordance to the values from the

LDRs, the rotation of the motors are controlled.

The following figure shows that the light dependant resistors are connected,

Four LDRs are placed on either sides of two sheets intertwined, this allows us to

detect the position of the sun by following points.

The LDR which receives maximum light closes the path for current. The program is

written such that the motors turn the entire such that, all the LDR receive maximum

light as possible.


A servo motor gives precise control of rotation, acceleration and even the velocity.

Since the solar tracker has to be employed throughout the day and the sun moves

over the horizon over span of 10~12 hours based in weather, we need precise

movement of the solar panels to get maximum sunlight. Hence servo motors are

preferred over any other motors. Also servo motors require very less power which

can be obtained by small batteries.

The motors we use in this project are micro servo which operate at 9v. It operates on

Direct current and hence easy to maintain and costs less too. The motors receive the

signal from LDRs via a microcontroller.

Micro controller is a small computer on a single integrated circuit containing a

processor core, memory and programmable input/output peripherals.

In our project we have to control the rotation of the two motor with respect to the

illumination of LDRs.

If we try to use any hardware means to make this system work, the system might

become bulky and design also becomes complicated. So we need a system which

reduces the size as well as improve the efficiency of the system.

This can be easily achieved by using a micro controller. A micro controller can be

used for interfacing the LDRs and the motors on one single board. Here we interface

the LDRs to the analog pins of the microcontroller and the motors to digital pins.

So here we can consider LDRs interfaced as the input peripheral and motors

interfaced as output peripherals.

We can use simple C++ coding to control the motors through the micro controller.

We have used an Arduino board which is a micro controller board. It is a small circuit

that contains whole computer on small chip. The main advantages of using these

boards are they are flexible, it’s great for developing interactive objects, software and

hardware.

It is optimal for our project because our project also uses interactive systems (i.e.

LDRs and motors).


4.2 Software and programming

The software used to dump the program into microcontroller is an open source

software called Arduino IDE. Using this software we can program the microcontroller

to run the motors. We can see from the figure the pin diagram of Arduino with an 8-

bit microcontroller ATmega328.


Coding for the rotation of the panels:

#include <Servo.h> // include Servo library

Servo horizontal; // horizontal servo

int servoh = 60; // stand horizontal servo

Servo vertical; // vertical servo

int servov = 60; // stand vertical servo

// LDR pin connections

// name = analogpin;

int ldrlt = 0; //LDR top left

int ldrrt = 2; //LDR top rigt

int ldrld = 1; //LDR down left

int ldrrd = 3; //ldr down rigt

void setup()

{

Serial.begin(4800);

// servo connections

// name.attacht(pin);

horizontal.attach(9);

vertical.attach(10);

}

void loop()

{

int lt = analogRead(ldrlt); // top left

int rt = analogRead(ldrrt); // top right

int ld = analogRead(ldrld); // down left

int rd = analogRead(ldrrd); // down rigt

int dtime = 51.2;//analogRead(4)/20; // read potentiometers

int tol = 256;//analogRead(5)/4;

int avt = (lt + rt) / 2; // average value top


int avd = (ld + rd) / 2; // average value down

int avl = (lt + ld) / 2; // average value left

int avr = (rt + rd) / 2; // average value right

int dvert = avt - avd; // check the diffirence of up and down

int dhoriz = avl - avr;// check the diffirence og left and rigt

if (-1*tol > dvert || dvert > tol) // check if the diffirence is in the tolerance else

change vertical angle

{

if (avt > avd)

{

servov = ++servov;

if (servov > 180)

{

servov = 180;

}

}

else if (avt < avd)

{

servov= --servov;

if (servov < 0)

{

servov = 0;

}

}

vertical.write(servov);

}

if (-1*tol > dhoriz || dhoriz > tol) // check if the diffirence is in the tolerance else

change horizontal angle

{

if (avl > avr)

{


servoh = --servoh;

if (servoh < 0)

{

servoh = 0;

}

}

else if (avl < avr)

{

servoh = ++servoh;

if (servoh > 180)

{

servoh = 180;

}

}

else if (avl == avr)

{ // nothing

}

horizontal.write(servoh);

}

delay(dtime);

}

The above written is the code used for the controlling and optimization of the solar

panel efficiency.

We can better understand the program with the help of a circuit diagram. The circuit

diagram shows us how the pins of Arduino are connected to LDRs and also the main

control circuit.


Circuit schematic diagram

The LDRs are interfaced using the analog pins 0, 1, 2 and 3 and the motors are

interfaced using the digital pins 9 and 10. The values each LDR is read by the

function analogRead().

The analog values read using this function is proportional to the amount of

illumination of the LDRs. We calculate the average values between two of the LDRs

and it is repeated for every combination of the LDRs. The Difference between the top

and down LDRs and left and right LDRs are calculated and compared to a tolerance

value (Here the tolerance value=256).


Depending the conditions checked with the tolerance requirements, signal is sent

through the digital pins and the vertical and horizontal motors are controlled and

brought to a position such that the LDRs are equally illuminated.

The rotation of the motors are controlled by the angles send to it through the digital

pins using the write () function.

The analog pins continuously monitor the light falling on the LDRs and according to

the calculation the motors are rotated which causes the Solar panel to receive

maximum amount of sunlight for the power generation.


5 Outcomes

Solar energy is the future, harnessing solar energy has been the aim of most of the

countries. Unlike other sources of energy, solar doesn’t need investment. The sun is

not going to run out of light and heat for few billion years. So harnessing solar energy

efficiently should be one of the major achievement of our country.

India as of now runs mostly on fossil fuels. Studies show us that up to 90% of the

energy generated in India are fossil fuels and other fuels which emit greenhouse

gases. Installing solar power plants with tracking system not only decreases the

need for fossil fuels it also keeps the environment clean with less global warming to

worry about.


5.1 Implementation in large scale

A dual axis solar tracker as explained in this project report is a prototype model. In

large scale very limited number of dual axis tracking system exist worldwide. Some

of the examples of solar power plant with tracking are

An ongoing pole mounted dual axis tracker project in Sizziwangqi

One of the largest dual axis solar trackers in New Mexico


Using solar tracking devices increases the efficiency of solar power plant setup

significantly. But the area required increases which again increase investment. Since

these investments are one time only it is better to have a tracking system in many

solar power generation stations.

We can see that the efficiency of solar panels with tracking system increases as it

increases the total sun hours. Sun hour is the amount of maximum duration of the

sunshine given by the sun. A dual axis solar tracker automatically adjusts towards

the thus throughout the day like a sunflower, thus increasing the sun hours. The

statistics show that the amount of energy converted with the help of solar tracker is

more than the fixed solar panels.

[Survey] - ISSN: 2319-5967 - International Journal of Engineering Science and

Innovative Technology (IJESIT)

A research study conducted has obtained the following data which conveys and

agrees with the theoretical concept of increase in the efficiency when a solar panel is

mounted on a solar tracker,

(a) Tabular column with recorded data of a fixed mount and solar panel mounted

on a dual axis solar tracker


(b) Output vs time curve indicates that the power obtained for the same amount

of time is more in case of the solar panel mounted on a solar tracker(dual

axis)

Comparison between fixed solar panel and solar panel with dual axis tracker system


5.2 Conclusion

It can be seen that adding anti-reflective coating to the solar panel significantly

reduces the amount of light reflected back. This in turn increases the amount of

sunlight in taken. More amount of sunlight is getting converted with the same area of

solar panel. Thus without increasing the size of the solar panel we are increasing the

efficiency of the same solar panel.

We have designed and built a dual axis solar tracker with a microcontroller

monitoring the entire circuit. This could be achieved by interfacing servo motors in

two axis to the main control circuit. Hence this allows the servo motors to rotate

precisely towards the sun. Rotary motion in two axis is difficult but can be achieved

with a little skill. The height of the solar tracker can be designed based on the

demands.

Even though the initial cost of the solar tracker is high, the increase in efficiency pays

off for this factor. Adding a solar tracker significantly increase the efficiency of the

solar power plant system as well as any household systems. Ultimately solar energy

utilization must be done effectively.

While solar energy has many advantages there are a few disadvantages. The initial

cost of installation can be steep, but when one takes overall savings into mind it can

be seen as a wise investment. When the weather or air pollution is bad it may be

harder to harvest the sun’s power. This disadvantage can be combated by using an

energy storage system that saves up power for use in the nocturnal hours and dark

days. With a little consideration most of the obstacles that may be presented by solar

energy can be overcome. Technology improves every day and with the cost of non-

renewable energy on the rise it’s easy to see why our global community needs to

focus on the future.


6 References

[1] Wikipedia; https://en.wikipedia.org/wiki

[2] PV Education; http://www.pveducation.org

[3] Instructables; www.instructables.com

[4] Energy Informative; http://energyinformative.org

[5] Million Solar Roofs; http://www.millionsolarroofs.com

[6] DF robot; http://www.dfrobot.com

[7] Electrical4U; http://www.electrical4u.com

[8] International Energy Agency; http://www.iea.org

[9] International Journal of Engineering Science and Innovative Technology

[10] Sono Tek http://www.sono-tek.com

https://en.wikipedia.org/wiki

http://www.pveducation.org/

http://www.instructables.com/

http://energyinformative.org/

http://www.millionsolarroofs.com/

http://www.dfrobot.com/

http://www.electrical4u.com/

http://www.iea.org/

http://www.sono-tek.com/

mini project report_artificial sunflower

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