solar tracker project

7/27/2019 Solar tracker project

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INTRODUCTION

1.1 HISTORY

Sun is the primary source of Energy. The earth receives 16 x 1018

units of energy

from the sun annually, which is 20,000 times the requirement of mankind on the Earth. Some

of the Solar Energy causes evaporation of water, leading to rains and creation of rivers etc.

Some of it is utilized in photosynthesis which is essential for sustenance of life on earth. Man

has tried from time immemorial to harness this infinite source of energy. But has been able to

tap only a negligibly fraction of this energy till today.

In the year 1767 a Swiss scientist named Horace-Benedict de Saussure created the

first solar collector an insulated box covered with three layers of glass to absorb heat

energy. Saussures box became widely known as the first solar oven, reaching temperatures

of 230 degrees fahrenheit.

In 1839 a major milestone in the evolution of solar energy happened with the defining

of the photovoltaic effect. A French scientist by the name Edmond Becquerel discovered this

using two electrodes placed in an electrolyte. After exposing it to the light, electricity

increased.

In 1873, Willoughby Smith discovered photoconductivity of a material known as

selenium. The discovery was to be further extended in 1876 when the same man discovered

that selenium produces solar energy. In 1977 the US government embraced the use of solar

energy by launching the Solar Energy Research Institute. Other governments across the

world soon followed.

In 1981, Paul Macready produced the first solar powered aircraft. The aircraft used

more than 1600 cells, placed on its wings. The aircraft flew from France to England. In the

year 1982 there was the development of the first solar powered cars in Australia.

The past few years have seen enormous investment in utility-scale solar plants, with

records for the largest frequently being broken. As of 2012, the historys largest solar energy

plant is the Golmud Solar Park in China, with an installed capacity of 200 megawatts. This is

arguably surpassed by Indias Gujarat Solar Park, a collection of solar farms scattered around

the Gujarat region, boasting a combined installed capacity of 605 megawatts.

The broad categories of possible large scale applications of solar power are the heating

and cooling of residential and commercial buildings.

A. The chemical and Biological conversion of organic material to liquid, solid and

gaseous fuels.

B. Conversion of solar energy to Electricity.


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In this project we use the solar energy for the generation of electrical energy, by using solar

cells.

The solar cell receives the solar energy. The solar cells operate on the principle of

photovoltaic effect, by using solar cells. Basically the cells are placed in an open and fixed

manner.

1.2 ENERGY SCENERIO

Drastic changes in energy conversion system are anticipated due to shortage of

conventional fuels. Fuel deposit in the world will soon deplete by the end of 2020. Fossil fuel

scarcity will be maximum. The main reasons for the above are due to increasing demand for

electricity, rising population, rapid advance in technology.

It is worthwhile to mention here that indiscriminate use of commercial energy has led

to serious environment problems like air and water pollutions. Man, when he is embarking on

use of alternate sources of energy should bear in mind, his environment. The creation of new

source of perennial environmentally acceptable, low cost electrical energy as a replacement

for energy from rapidly depleting resources of fossil fuels is the fundamental need for the

survival of mankind.

1.3 SOLAR ENERGY OPTIONS

Solar energy has the greatest potential of all the sources of renewable energy and it

will be one of the most important sources of energy especially when other sources in the

country have depleted. Solar energy could supply all the present and future energy needs of

the world on a connecting basis. This makes it one of the most promising of the

nonconventional energy sources.

Solar Energy can be a major source of power. Its potential is 178 billion MW which

is about 20,000 times the worlds demand. The energy radiated by the sun on a bright sunny

day is approximately 1kw/m2. The problem associated with the use of solar energy is that its

availability varies widely with time. The variations in availability occur daily, because of the

day-night cycle and also seasonally because of Earths orbit around the sun. In addition


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variations occur at a specific location because of local weather conditions. Consequently the

energy collected with the sun is shining must be stored for use during periods when it is not

available. Attempts have been made to make use of this energy in raising steam which may

be used in driving the prime movers for the purpose of generation of electrical energy.

However due to large space requirement and uncertainty of availability in constant rate this

method becomes ineffective.

Photovoltaic cell is an alternate device used for power generation which converts suns

radiation directly into electrical power. Thus power generated can be stored and utilized.

1.4 GENERAL CONCEPT

In 1968 Dr. Peter Glaser in the U.S. Published an idea that centered on the fact that in

orbit close to earth, 1.43 KW of solar energy illuminates may one square meter which is

considerably greater and one more continuous than an anyone square meter on the Earth

which, even when perpendicular to the sun can receive only a maximum of 1 kw. His idea

was, converting sunlight to electricity to convert to a radio frequency signal and beamed

down to the earth carrying significant levels of energy. This electricity is by establishing a

very large array of solar cells in geostationary orbit. A receiving antenna station on the earth

would convert this radio frequency back into an alternate current which would be fed into a

local grid.

The applications of solar energy which are enjoying most success today are:

1) heating and cooling of residential buildings

2) Solar water heating

3) Solar drying of agriculture and animal products

4) Solar distillation on a small community scale

5)

Salt production by evaporation of seawater or inland brines6) Solar cookers

7) Solar engines for water pumping

8) Food refrigeration

9) Bio conversion and wind energy, which are indirect source of solar energy


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10) Solar furnaces

1.5 ENVIRONMENTAL IMPACT OF SOLAR POWER

1.5.1 AIR POLLUTION

This can be caused by chemical reactants used in storage or organic fluids for heat

transport. The release of CO, SO2, SO3, hydrocarbon vapors and other toxic gases should be

accounted, though their magnitude is not high. The fire hazard associated with overheated

organic working fluids exists. Human tissues when exposed would be destroyed because of

high energy flux densities.

1.5.2 LAND USES

Solar plants require large land and the collection field produce shading not normally

present over large areas. This may cause disturbance in local ecosystem.

1.5.3 NOISE AND THERMAL EFFECT

The thermal effects of solar plants are minimal. Actually these systems eliminate

local thermal pollution associated with fossil fuel combustion. Some reduction in local

environmental heat budget or balance will occur if electricity produced is exported

elsewhere. Solar systems do not add any new noise to that already existing in the present

industrial or utility areas.

1.6 MAJOR ADVANTAGES OF SOLAR CELL

1) Solar cells directly convert the solar radiation into electricity using photovoltaic effect

without going through a thermal process.

2) Solar cells are reliable, modular, durable and generally maintenance free and

therefore, suitable even in isolated and remote areas.

3) Solar cells are compatible with almost all environments, respond instantaneously with

solar radiation and have an expected life time of 20 or more years.

Solar cells can be located at the place of use and hence no distribution network is required.


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1.7 LIMITATIONS OF USING SOLAR ENERGY

1. Solar energy can only be harnessed when it is daytime and sunny.

2.Solar collectors, panels and cells are relatively expensive to manufacture although prices

are falling rapidly.

3.Solar power stations can be built but they do not match the power output of similar sized

conventional power stations. They are also very expensive.

4.In countries such as the UK, the unreliable climate means that solar energy is also

unreliable as a source of energy. Cloudy skies reduce its effectiveness.

5.Large areas of land are required to capture the suns energy. Collectors are usually arranged

together especially when electricity is to be produced and used in the same location.

6.Solar power is used to charge batteries so that solar powered devices can be used at night.

However, the batteries are large and heavy and need storage space. They also need replacing

from time to time.

1.8 PRINCIPLES OF OPERATION SOLAR PHOTOVOLTAICS

The solar energy can be directly converted into electrical energy by means of

photovoltaic effect, i.e. conversion of light into electricity. Generation of an electromotive

force due to absorption of ionizing radiation is known as photovoltaic effect.

The energy conversion devices which are used to convert sunlight to electricity by use

of the photovoltaic effect are called solar cells.

Photo voltaic energy conversion is one of the most popular nonconventional energy

sources. The photovoltaic cell offers an existing potential for capturing solar energy in a way

that will provide clean, versatile, renewable energy. This simple device has no moving parts,

negligible maintenance costs, produces no pollution and has a lifetime equal to that of a

conventional fossil fuel.

Photovoltaic cells capture solar energy and convert it directly to electrical current by

separating electrons from their parent atoms and accelerating them across a one way


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electrostatic barrier formed by the junction between two different types of semiconductor

material.

1.8.1 PHOTOVOLTAIC EFFCT ON SEMICONDUCTOR

Semiconductors are materials which are neither conductors nor insulators. The photo

voltaic effect can be observed in nature in a variety of materials but semiconductors has

shown best performance.

When photons from the sun are absorbed in a semiconductor they create for electrons

with higher energies than the electrons which provide the boarding in the base crystal.

Once these electrons are created, there must be an electric field to induce these higher

energy electrons to flow out of the semiconductor to do useful work. The electric field in

most solar cells is provided by a junction of materials which have different electrical

properties.

To understand more about the functioning and properties of semiconductors, let us

briefly discuss. Semiconductors are classified into 1) Extrinsic semiconductor 2) Intrinsic

semiconductor. Semiconductors in its purest form are called intrinsic and when impurities are

added it is called extrinsic. Further extrinsic semiconductors are divided into p type and N

type semiconductor.

1.8.2 P-TYPE SEMICONDUCTOR

When a small amount of pentavalent impurities (e.g. Gallium, Indium, Aluminum,

and Boron) are added to intrinsic semiconductor, it is called as p type semiconductor.

In p type semiconductor, when an electric potential is applied externally, the holes are

directed towards the negative electrode. Hence current is produced.

1.8.3 N- TYPE SEMICONDUCTOR

When a small amount of pentavalent impurities (e.g. Antimony, Arsenic, Bismuth,

Phosphorus) are added to intrinsic semiconductors it is called N type semiconductor.


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When an external electrical field is applied the free electrons are directed towards

positive electrode. Hence current is produced.

1.8.4 PN JUNCTION SILICON SOLAR CELL

A PN junction is formed from a piece of semiconductor by diffusing p type materials

to one half side and N type materials to other half side.

It consists of both types of semiconductor materials. The N type layer is situated

towards the sunlight. As N type layer is thin, light can penetrate through it.

The energy of the sunlight will create free electron in the N type material and holes in

the p type material. This condition built up the voltage with in the crystal. Because the

electrons will travel to the +ve region and the holes will travel to the ve region. This

conduction ability is one of the main technical goals in fabricating solar cells.

1.9 PURIFICATION AND REFORMATION INTO WAFERS

The purification process basically entails high temperature melting of the sand and

simultaneous reduction in the presence of hydrogen. This results in a very pure

polycrystalline form of silicon.

The next step is to reform this silicon into a single crystal and then cut the crystal into

a single crystal and then cut the crystal into individual wafers. There are two methods namely

czochralski growth method and film fed growth. The former method produces single,

cylindrical crystals and later produces continuous ribbon of silicon crystals.

Then this cylindrical crystal and ribbon crystal is transformed into disc shaped cells

and rectangular cells by slicing. After that one side is doped by exposure to high temperature

phosphorus, forming a thin layer of N type material. Similarly p type is made. Electrical

contacts are applied to the two surfaces, an anti-reflection coating is added to the entire

surface and the entire cell is then sealed with protective skin.

1.10 ANTIREFLECTIVE COATING


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Antireflective coating (arc) is an important part of a solar cell since the bare silicon

has a reflection coefficient of 0.33 to 0.54 in the spectral range of 0.35 to 1.1 cm. The arc not

only reduces the reflection losses but also lowers the surface recombination velocity. A

single optimal layer of ARC can reduce the reflection to 10 percent and two layers can

reduce the reflection up to 3 percent in desired range of wavelengths.

Fig 1.1 A Typical n-on-p-photovoltaic

Generally, Arcs are produced on the solar cell by vacuum evaporation process and the

coatings which are tried are SiO2, SiO, Al2O3, TiO2, Ta2O5 and Si3N4. Other methods of

deposition are sputtering, spin-on, spray-on or screen printing. Only the vacuum evaporation

sputtering give good results but are expensive. The average reflection can be further reduced

by using two antireflective coatings instead of one where the outside (exposed side) coating

has an index of refraction 1.3 to 1.6 and the second layer between silicon and the first layer

has an index of refraction 2.2 to 2.6. This two layer ARC gives a better impedance match

between the index of silicon and the index of air.


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Fig1.2 Reflective coating

SOLAR TRACKER

A solar trackeris a device that orients a payload toward the sun. Payloads can

bephotovoltaic panels,reflectors, lenses or other optical devices.

In flat-panelphotovoltaic (PV) applications, trackers are used to minimize theangle

of incidencebetween the incoming sunlight and a photovoltaic panel. This increases the

amount of energy produced from a fixed amount of installed power generating capacity. In

standard photovoltaic applications, it was predicted in 2008-2009 that trackers could be used

in at least 85% of commercial installations greater than 1MW from 2009 to 2012. However,

as of April 2014, there is no any data support these predictions.

Inconcentrated photovoltaic (CPV) andconcentrated solar thermal

(CSP) applications, trackers are used to enable the optical components in the CPV and CSP

systems. The optics in concentrated solar applications accept the direct component of

sunlight light and therefore must be oriented appropriately to collect energy. Trackingsystems are found in all concentrator applications because such systems do not produce

energy unless pointed at the sun.

Sunlight has two components, the "direct beam" that carries about 90% of the solar

energy, and the "diffuse sunlight" that carries the remainder - the diffuse portion is the bluesky on a clear day and increases proportionately on cloudy days. As the majority of the

energy is in the direct beam, maximizing collection requires the sun to be visible to the

panels as long as possible.

The energy contributed by the direct beam drops off with thecosine of the angle

between the incoming light and the panel. In addition, the reflectance (averaged acrossallpolarizations)is approximately constant for angles of incidence up to around 50, beyond

which reflectance degrades rapidly.

I Lost = 1 -cos(i) i Hours Lost
http://en.wikipedia.org/wiki/Solar_panelhttp://en.wikipedia.org/wiki/Photovoltaicshttp://en.wikipedia.org/wiki/Angle_of_incidencehttp://en.wikipedia.org/wiki/Angle_of_incidencehttp://en.wikipedia.org/wiki/Concentrated_photovoltaicshttp://en.wikipedia.org/wiki/Concentrated_solar_powerhttp://en.wikipedia.org/wiki/Concentrated_solar_powerhttp://en.wikipedia.org/wiki/Solar_irradiationhttp://en.wikipedia.org/wiki/Lambert%27s_cosine_lawhttp://en.wikipedia.org/wiki/Reflectancehttp://en.wikipedia.org/wiki/Polarization_(waves)http://en.wikipedia.org/wiki/Cosinehttp://en.wikipedia.org/wiki/Cosinehttp://en.wikipedia.org/wiki/Polarization_(waves)http://en.wikipedia.org/wiki/Reflectancehttp://en.wikipedia.org/wiki/Lambert%27s_cosine_lawhttp://en.wikipedia.org/wiki/Solar_irradiationhttp://en.wikipedia.org/wiki/Concentrated_solar_powerhttp://en.wikipedia.org/wiki/Concentrated_solar_powerhttp://en.wikipedia.org/wiki/Concentrated_photovoltaicshttp://en.wikipedia.org/wiki/Angle_of_incidencehttp://en.wikipedia.org/wiki/Angle_of_incidencehttp://en.wikipedia.org/wiki/Photovoltaicshttp://en.wikipedia.org/wiki/Solar_panel


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0 0% 15 1 3.4%

1 0.015% 30 2 13.4%

3 0.14% 45 3 30%

8 1% 60 4 >50%

23.4[8]

8.3% 75 5 >75%

TRACKERS

Even though a fixed flat-panel can be set to collect a high proportion of availablenoon-time energy, significant power is also available in the early mornings and late

afternoonswhen the misalignment with a fixed panel becomes excessive to collect a

reasonable proportion of the available energy. For example, even when the Sun is only 10

above the horizon the available energy can be around half the noon-time energy levels (oreven greater depending on latitude, season, and atmospheric conditions).

Thus the primary benefit of a tracking system is to collect solar energy for the longest

period of the day, and with the most accurate alignment as the Sun's position shifts with the

seasons.

In addition, the greater the level of concentration employed, the more important

accurate tracking becomes, because the proportion of energy derived from direct radiation is

higher, and the region where that concentrated energy is focused becomes smaller.

DISADVANTAGES

Trackers add cost and maintenance to the system - if they add 25% to the cost, andimprove the output by 25%, the same performance can be obtained by making the system25% larger, eliminating the additional maintenance.
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ANGLES AFFECTING SOLAR ENERGY COLLECTION

In solar radiation analysis, the following angles are useful:

l= latitude of location

= declination

= hour angle

s = solar azimuth angle

s = slope

= altitude angle

z= zenith angle

INCIDENT ANGLE

If is the angle between an incident beam radiation I and the normal to the plane

surface, then the equivalent flux or radiation intensity falling normal to the surface is given by

Icos, where is called incident angle.

LATITUDE OF LOCATION

The altitude1 of a point or location is the angle made by the radial line joining the

location to the centre of the earth with the projection of the line on the equatorial plane.it isthe angular distance north or south of the equator measured from centre of the earth.

DECLINATION ANGLE

The declination is the angular distance of the suns rays north (or south) of the

equator. It is the angle between a line extending from the centre of the sun to the centre of the

earth and the projection of this line upon the earths equatorial plane.


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( in degrees) = 23.45

..(1)

where n is the day of the year

HOUR ANGLE

The hour angle is the angle through which the earth must turn to bring the meridian

of a point directly in line with the suns rays. The hour angle is equivalent to 15per hour.

It is measured from noon based on the local solar time (LST) or local apparent time, being

positive in the morning and negative in the afternoon.

ALTITUDE ANGLE (SOLAR ALTITUDE)

It is a vertical angle between the projection of the suns rays on the horizontal plane

and the direction of suns rays.

ZENITH ANGLE (Z)

It is complimentary angle of suns altitude angle. It is a vertical angle between the

suns rays and a line perpendicular to the horizontal plane through the point i.e. the angle

between the beam from the sun and the vertical

z = /2

SOLAR AZIMUTH ANGLE (s): It is the solar angle in degrees along the horizon

east or west of north or it is a horizontal angle measured from north to the horizontal

projection of the suns rays. This angle is positive when measured west wise.

Altitude angle , zenith angle z, and solar azimuth angle s, can be expressed in

terms of 1 (latitude angle), (declination), and (hour angle), which are also called basic

angles. The expressions are:

Cos z =cos cos cos +sin sin ..(2)

Cos s=sec (cos sin - cos sin cos ) ..(3)

And

sin s= sec cos sin ..(4)

These equations allow calculation of the suns zenith altitude and azimuth angles,

if the declination, hour angles and latitude are known. In applying these equations, attention

must be given to correct signs for the latitude and declination and angle. If north latitudes are

considered positive and south latitudes negative, the declination will be positive for the

summer period between the vernal equinox and autumnal equinox ( march 22 to September


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22 approximately ) and negative at other times. For non-horizontal surfaces, the other angles,

such as incident angle, slope angle, surface azimuth angle, etc. are important angles.

THE SLOPE(s)

It is the angle made by the plane surface with the horizontal. It is taken to be positivefor surfaces slopping towards the south and negative for surface slopping towards the north.

SURFACE AZIMUTH ANGLE()

It is the angle of deviation of the normal to the surface from the local meridian, the

zero point being south, east positive and west negative.

INCIDENT ANGLE()

It is the angle being measured between the beam of rays and normal to the plane.

From spherical geometry the relation between and other angles is given by theequation

Cos = sin 1 (sin cos s + cos cos cos sin s )

+cos 1 (cos cos cos s - sin cos sin s )

+ cos sin sin sin s ..(5)

Where 1 = latitude (north positive)

= declination (north positive)

= hour angle, it is positive between solar mid-night and noon, otherwise negative.

At solar noon being zero and each hour angles equating 15 of longitude with

morning positive and afternoon negative (e.g. =+ 15for 11:00and = -37.5 for 14:30) hour

angle can be expressed mathematically as :

= 15(12 LST)

Simpler versions of equation (5) are normally required. Some of these are as follows :

For vertical surfaces, s =90,equation (5) becomes

Cos = sin cos cos cos - cos sin cos +cos sin sin ..(6)

For horizontal surfacess=0, = z zenith angle

Cos z = sin sin + cos cos cos ..(7)


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= sin

i.e. cos = cosz =sin ..(8)

for surface facing due south = 0,

Cos T= sin (sin cos s+ cos cos sin s)

= cos (cos cos cos s sin sin s)

(incident angle is expressed as T, denoting the surface as tilted one)

= sin sin( - s) + cos cos cos( -s) ..(9)

Vertical surfaces facing due south (s=90, =0)

Cos z =sin cos cos cos sin ..(10)

Day length at the timeof sun rise or sun set, the zenith angle, z = 90, substituting this in

equation(2), we obtain sun rise hour angle (s)

Coss = -

= - tan tan

s = .(11)

since 15 of the hour angle are equivalent to 1 hour, the day length (in hours)

td =

=

..(12)

Therefore, the length of the day (td) is a function of latitude and solar declination.

The hour angle at sun rise or sun set on an inclined surface will be lesser than the

value obtained by equation (12), if the corresponding incidence angle comes out to be more

than 90. Under this condition, by putting = 90, in equation (5) or one of its simple

versions. Thus for an inclined surface facing south substituting = 90, in equation (9), we

obtain

st = ..(13)

the corresponding day length ( in hours) is then given by


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td =

..(14)

EQUIPMENT

FRAME:

Frame is the supporting structure for the solar panel. Also it is useful for orienting

the panel in any angle. The frame is made up of cast iron and I-section is used.

There are two standard I-beam forms:

Rolled I-beam, formed by hot rolling, cold rolling or extrusion (depending on

material).

Plate girder, formed bywelding (or occasionallybolting orriveting)plates.

I-beams are commonly made ofstructural steelbut may also be formed fromaluminum

or other materials.
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DESIGN

Fig 3.1 Isection

I-beams are widely used in theconstruction industry and are available in a variety of

standard sizes. Tables are available to allow easy selection of a suitable steel I-beam size for

a given applied load. I-beams may be used both as beams and ascolumns.

I-beams may be used both on their own, or actingcompositely with another material,

typicallyconcrete.Design may be governed by any of the following criteria:

deflection:thestiffness of the I-beam will be chosen to minimize deformation

vibration: the stiffness and mass are chosen to prevent unacceptable vibrations,

particularly in settings sensitive to vibrations, such as offices and libraries

bending failure by yielding:where the stress in the cross section exceeds the yield

stress

bending failure bylateral tensional buckling:where a flange in compression tends to

buckle sideways or the entire cross-section buckles torsionally

bending failure bylocal buckling:where the flange or web is so slender as to buckle

locally

local yield: caused by concentrated loads, such as at the beam's point of support

shear failure:where the web fails. Slender webs will fail by buckling, rippling in a

phenomenon termed tension field action, but shear failure is also resisted by the

stiffness of the flanges
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buckling or yielding of components: for example, of stiffeners used to provide

stability to the I-beams web.

In this instrument I-section is used to support the solar panel

2.1 MOTOR

Dc motors tend to spin too quickly and do not have enough torque to drive directly,

so some kind of gear reduction will have to be used. The gears both slow down the speed and

increase the torque of the output shaft. This gearbox can be created out of individual gears or

it can be part of the motor. By knowing the output shaft's speed (RPM) and the diameter of

the wheel you will be using, you can get an idea of how fast your mouse will be traveling

through the maze.

Fig 2.1 Stepper motor

Specifications:

Speed = 1000 rpm


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2.4.3.3 SOLAR PANEL

Photovoltaic cells are devices that absorb sunlight and convert that solar energy into

electrical energy. Solar cells are commonly made of silicon, one of the most abundant

elements on Earth. Pure silicon, an actual poor conductor of electricity, has four outer

valence electrons that form tetrahedral crystal lattices.

Fig 2.10Solar panel

When photons (sunlight) hit a solar cell, its energy frees electron-holes pairs. The

electric field will send the free electron to the N side and holes to the P side. This causes

further disruption of electrical neutrality, and if an external current path is provided, electrons

will flow through the path to their original side (the P side) to unite with holes that the

electric field sent there, doing work for us along the way. The electron flow provides the

current, and the cell's electric field causes a voltage. With both current and voltage, we have

power, which is the product of the two. By wiring solar cells in series, the voltage can be

increased; or in parallel, the current. Solar cells are wired together to form a solar

panel. Solar panels can be joined to create a solar array


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Fig 2.12 Working

The performance of a photovoltaic array is dependent upon sunlight. Climate

conditions (e.g., clouds, fog) have a significant effect on the amount of solar energy received

by a photovoltaic array and, in turn, its performance. Most current technology photovoltaic

modules are about 10 percent efficient in converting sunlight. Further research is being

conducted to raise this efficiency to 20 percent.

In our project, we used a solar panel of

Dimensions:

Surface area:

The characteristics of the solar cell array are as below:

Type of semi-conductor used for cell : silicon

Number of arrays : 2

Power : 36 watt x 2 = 72 watt Open circuit voltage : 21V

Short circuit current : 3.6 ampere


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2.2 INVERTER

So how can an inverter give us a high voltage alternating current from a low voltage

direct current? Let's first consider how an alternator produces an alternating current. In its

simplest form, an alternator would have a coil of wire with a rotating magnet close to it. As

one pole of the magnet approaches the coil, a current will be produced in the coil. This

current will grow to a maximum as the magnet passes close to the coil, dying down as the

magnetic pole moves further away. However when the opposite pole of the magnet

approaches the coil, the current induced in the coil will flow in the opposite direction.

Fig 2.3INVERTER

As this process is repeated by the continual rotation of the magnet, an alternating

current is produced. Now letsconsider what a transformer does. A transformer also causes

an electric current to be induced in a coil, but this time, the changing magnetic field is

produced by another coil having an alternating current flowing through it. Any coil with an


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electric current flowing through it will act like a magnet and produce a magnetic field .If the

direction of the current changes then the polarity of the field changes.

Now, the handy thing about a transformer is that, the voltage produced in the

secondary coil is not necessarily the same as that applied to the primary coil. If the secondary

coil is twice the size (has twice the number of turns) of the primary coil, the secondary

voltage will be twice that of the voltage applied to the primary coil. We can effectively

produce whatever voltage we want by varying the size of the coils.

Fig 2.4 Step up transformer

If we connected a direct current from a battery to the primary coil it would not induce

a current in the secondary as the magnetic field would not be changing. However, if we can

make that direct current effectively change direction repeatedly, then we have a very basic

inverter. This inverter would produce a square wave output as the current would be changingdirection suddenly.

Fig 2.5 Inverter

This type of inverter might have been used in early car radios that needed to take 12

volts available in the car and produce the higher voltages required to run radio valves (known

as tubes in America) in the days before transistors were widely used.

A more sophisticated inverter would use transistors to switch the current. The switching


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22

transistors are likely to be switching a small current which is then amplified by further

transistor circuitry. This will still be a square wave inverter

2.3 MICROCONTROLLER

Microcontroller is a complete microprocessor system built on a single IC.

Microcontrollers were developed to meet a need for microprocessors to be put into low cost

products. Building a complete microprocessor system on a single chip substantially reduces

the cost of building simple products, which use the microprocessor's power to implement

their function, because the microprocessor is a natural way to implement many products.

This means the idea of using a microprocessor for low cost products comes up often. But the

typical 8-bit microprocessor based system, such as one using a Z80 and 8085 is expensive.

Both 8085 and Z80 system need some additional circuits to make a microprocessor system.

Each part carries costs of money. Even though a product design may require only very simple

system, the parts needed to make this system as a low cost product.

Fig 2.6Microconroller

2.3.1 APPLICATION OFMICROCONTROLLER

Microcontrollers are designed for use in sophisticated real time applications such as

1. Industrial Control

2. Instrumentation and


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23

3. Intelligent computer peripherals

They are used in industrial applications to control

Motor

Robotics

Discrete and continuous process control

In missile guidance and control

In medical instrumentation

Oscilloscopes

Telecommunication

Automobiles

For scanning a keyboard

Driving an LCD

For Frequency measurements

Period Measurements

2.3.2 PIC16F877 MICROCONTROLLER FEATUTRE

1. High performance RISC CPU

2. Only 35 single word instructions to learn

3. All single cycle instructions except for program branches which are two cycle

4.

Up to 8K x 14 words of FLASH Program Memory, Up to 368 x 8 bytes ofData Memory (RAM) up to 256 x 8 bytes of EEPROM Data Memory

5. Interrupt capability (up to 14 sources)

6. Direct, indirect and relative addressing modes

7. Power-on Reset (POR)

8. Power-up Timer (PWRT) and Oscillator Start-up Timer (OST)


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9. Watchdog Timer (WDT) with its own on-chip RC oscillator for reliable operation

10.Programmable code protection

11.Power saving SLEEP mode

12.Selectable oscillator options

13.Low power, high speed CMOS FLASH/EEPROM technology

14.Fully static design

15.In-

16.Single 5V In-Circuit Serial Programming capability

17.In-Circuit Debugging via two pins

18.Processor read/write access to program memory

19.Wide operating voltage range: 2.0V to 5.5V

20.

High Sink/Source Current: 25 mA

21.Commercial, Industrial and Extended temperature ranges

2.3.3 PIN DIAGRAM

Fig2.7 Microcontroller block diagram

2.4 BATTERY


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In most alone PV power systems, storage batteries with charge regulators have to be

incorporated to provide a backup power source during periods of low solar irradiance and

night. Several types of accumulator are available in the market for use in PV power systems.

The main requirements to be met by an accumulator for solar power system are,

Ability to withstand several charge/discharge cycle.

A low self-discharge rate

Little or no need for maintenance

Fig 2.8 Battery

The capacity of a battery is the total amount of electricity that can be drawn from afully charged battery at a fixed discharge rate and electrolyte temperature until the voltage

falls to a specified minimum. It is expressed in ampere hour. The capacity of the battery also

depends upon the temperature and age of battery.

The batteries in most PV systems are of lead acid type consisting of one or more 2v

cells. Each cell has a positive plate of lead peroxide and a negative plate of sponge lead. The

electrolyte is dilute sulphuric acid. During discharging when current is drawn from it, the

material of both plates changes to lead sulphate and water content in the electrolyteincreases thereby reducing its specific gravity.

When the battery is charged by passing electric current through it in the opposite

direction, the reverse chemical reaction takes place. The cell voltages are typically 2.4v and


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26

1.9v for fully charged and deeply discharged battery respectively. Lead acid batteries self-

discharge slowly when not in use.

The characteristics of the battery are as below:

Type : Lead acid tubular battery

Ampere hour efficiency : 90 to 95%

Watt hour efficiency : 70 to 80%

Capacity: 7 AH, 12V.

2.4.1 CHARGE CONTROLLER

Overcharging of some batteries results in loss of electrolytic, corrosion, plate growth

and loss of active material from the plates, causing reduction in battery life. Also, therepeated failure to reach full charge also leads to stratification of electrolyte.

Thus, there is a need of charge regulators to optimize the battery life. Most charge

regulators start the charging process with a high current and reduce it to a very low level

when a certain battery voltage is reached. A digital based charge regulator monitors the

battery current, and voltage computes the level of charge and regulates the input and output

currents so as to avoid both overcharging and excessive discharge. LOAD For continuous

operation, we use solar cells for charging DC LAMP.

The characteristics of controller are as below:

Low voltage cut off

Over charge disconnect

Operating current : 10 ampere

High copper rich 10amp wire for minimum power loss is used for connections in the circuit.

2.4.3.1ADVANTAGES OF CHARGING/DISCHARGING

(1) Protect unit from reverse connection of battery

(2) Solar cell Polarity reversal

(3) Battery short circuit Protection (Electronic Fuse)

(4) Color all overload Protection


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(5) Battery charge level maintenance

(6) Battery discharge limit

2.4.3.2 ABSENCE OF CHARGING/DISCHARGING UNIT CAUSE

1)

Solar cell may get affected due to over loading.

2) Battery life shortened

2.4.4PROGRAM OF MICROCONTROLLER

#include

#include

#include

#include"lcd.h"

#include"delay.h"

#include"adc.h"

#define G1 RB1

#define B1 RB2

#define M1 RB7

#define M2 RB6

#define SW2 RB5

#define SW3 RB4

#define _LEGACY_HEADERS

__CONFIG(FOSC_HS & PWRTE_OFF & CPD_OFF & CP_OFF& BOREN_OFF &

DEBUG_OFF & WDTE_OFF & LVP_OFF);

unsigned char Temp _dat=0,count_num=0,Temp_Arr[6];


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unsigned char x,d1,d2,d3,count=0,time=0;

void rf_tx(unsigned char a);

void convert(unsigned char binbyte)

{

x =binbyte/10;

d1=(binbyte%10)+48;

d2=(x%10)+48;

d3=(x/10)+48;

}

void main()

{

unsigned char adc_value=0,adc_value2=0;

static unsigned char q,f;

TRISB = 0b00011111;

PORTB = 0xFF;

TRISC = 0b10010000;

PORTC = 0xff;

lcd_init();

DelayMs(50);

init_adc();

// serial_setup();


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lcdcmd(0x80);

lcd_puts("Monitoring . . .");

while(1)

{

lcd_clear();

lcdcmd(0x80);

lcd_puts("Monitoring . . .");

adc_value = adc_read(0);

adc_value = (adc_value /10);

convert(adc_value);

lcdcmd(0xC0);

lcd_puts("V:");

lcddata(d3);

lcddata(d2);

lcddata(d1);

lcddata(' ');

DelayMs(50);

do

{

M1 = 1;

M2 = 0;


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convert(adc_value);

lcdcmd(0xC0);

lcd_puts("V:");

lcddata(d3);

lcddata(d2);

lcddata(d1);

lcdcmd(0xCF);

lcddata('F');

DelayS(1);

if(adc_value>=9)

{

M1 = 0;

M2 = 0;

DelayMs(250);

break;

}

}

while(G1!=0);

count=0;


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DelayS(1);

do

{

M1 = 0;

M2 = 1;



convert(adc_value);

lcdcmd(0xC0);

lcd_puts("V:");

lcddata(d3);

lcddata(d2);

lcddata(d1);

lcdcmd(0xCF);

lcddata('R');

DelayS(1);

if(adc_value>=9)

{ // motor stop

M1 = 0;

M2 = 0;

DelayMs(250);


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break;

}

}while(B1!=0);

while(adc_value>=6)

{

M1 = 0;

M2 = 0;

DelayMs(250);



convert(adc_value);

lcdcmd(0xC0);

lcd_puts("V:");

lcddata(d3);

lcddata(d2);

lcddata(d1);

lcd_clear();

lcdcmd(0x80);

lcd_puts("PANEL STOPPED ");

lcdcmd(0xC0);

lcd_puts("ABOVE 9V ");


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}

while(adc_value


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}

}

3.3 BALL BEARING

Ball bearing are extremely common because they can handle both radial and thrust

loads, but can only handle a small amount of weight. They are found in a wide array of

applications, such as roller blades and even hard drives, but are prone to deforming if they

are overloaded.

These are used for the free rotation of the components

Fig 3.4Ball bearing

TRACKING ALTERNATIVES

The movement of most modern heliostats employs a two-axis motorized system,

controlled by computer as outlined at the start of this article. Almost always, the primaryrotation axis is vertical and the secondary horizontal, so the mirror is on analt-azimuth

mount.

One simple alternative is for the mirror to rotate around apolar alignedprimary axis,driven by a mechanical, often clockwork, mechanism at 15 degrees per hour, compensating

for the earth's rotation relative to the sun. The mirror is aligned to reflect sunlight along the

same polar axis in the direction of one of thecelestial poles. There is a perpendicularsecondary axis allowing occasional manual adjustment of the mirror (daily or less often as

necessary) to compensate for the shift in the sun'sdeclination with the seasons. The setting of

the drive clock can also be occasionally adjusted to compensate for changes in theEquation

of Time.The target can be located on the same polar axis that is the mirror's primary rotationaxis, or a second, stationary mirror can be used to reflect light from the polar axis toward the

target, wherever that might be. This kind of mirror mount and drive is often used withsolar

cookers,such asScheffler reflectors.[11][12][13]

For this application, the mirror can beconcave,

so as to concentrate sunlight onto the cooking vessel.

The alt-azimuthand polar-axisalignments are two of the three orientations for two-

axis mounts that are, or have been, commonly used for heliostat mirrors. The third is

thetarget-axisarrangement in which the primary axis points toward the target at which
http://en.wikipedia.org/wiki/Altazimuth_mounthttp://en.wikipedia.org/wiki/Altazimuth_mounthttp://en.wikipedia.org/wiki/Polar_alignmenthttp://en.wikipedia.org/wiki/Celestial_polehttp://en.wikipedia.org/wiki/Declinationhttp://en.wikipedia.org/wiki/Equation_of_Timehttp://en.wikipedia.org/wiki/Equation_of_Timehttp://en.wikipedia.org/wiki/Solar_cookerhttp://en.wikipedia.org/wiki/Solar_cookerhttp://en.wikipedia.org/wiki/Solar_energy#Cookinghttp://en.wikipedia.org/wiki/Heliostat#cite_note-11http://en.wikipedia.org/wiki/Heliostat#cite_note-11http://en.wikipedia.org/wiki/Heliostat#cite_note-13http://en.wikipedia.org/wiki/Heliostat#cite_note-13http://en.wikipedia.org/wiki/Curved_mirror#Concave_mirrorshttp://en.wikipedia.org/wiki/Curved_mirror#Concave_mirrorshttp://en.wikipedia.org/wiki/Heliostat#cite_note-13http://en.wikipedia.org/wiki/Heliostat#cite_note-11http://en.wikipedia.org/wiki/Heliostat#cite_note-11http://en.wikipedia.org/wiki/Solar_energy#Cookinghttp://en.wikipedia.org/wiki/Solar_cookerhttp://en.wikipedia.org/wiki/Solar_cookerhttp://en.wikipedia.org/wiki/Equation_of_Timehttp://en.wikipedia.org/wiki/Equation_of_Timehttp://en.wikipedia.org/wiki/Declinationhttp://en.wikipedia.org/wiki/Celestial_polehttp://en.wikipedia.org/wiki/Polar_alignmenthttp://en.wikipedia.org/wiki/Altazimuth_mounthttp://en.wikipedia.org/wiki/Altazimuth_mount


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sunlight is to be reflected. The secondary axis is perpendicular to the primary one. Heliostats

controlled by light-sensors have used this orientation. A small arm carries sensors that

control motors that turn the arm around the two axes, so it points toward the sun. (Thus thisdesign incorporates a solar tracker.) A simple mechanical arrangement bisects the angle

between the primary axis, pointing to the target, and the arm, pointing to the sun. The mirror

is mounted so its reflective surface is perpendicular to this bisector. This type of heliostat wasused fordaylightingprior to the availability of cheap computers, but after the initialavailability of sensor control hardware.

There are heliostat designs which do not require the rotation axes to have any exact

orientation. For example, there may be light-sensors close to the target which send signals to

motors so that they correct the alignment of the mirror whenever the beam of reflected lightdrifts away from the target. The directions of the axes need be only approximately known,

since the system is intrinsically self-correcting. However, there are disadvantages, such as

that the mirror has to be manually realigned every morning and after any prolonged cloudy

spell, since the reflected beam, when it reappears, misses the sensors, so the system cannotcorrect the orientation of the mirror. There are also geometrical problems which limit the

functioning of the heliostat when the directions of the sun and the target, as seen from themirror, are very different. Because of the disadvantages, this design has never beencommonly used, but some people do experiment with it.

2/3rd motion heliostat:

In general, in heliostats, the bisector angular motion of the mirror moves at a rate that

is 1/2 the angular motion of the sun. There is another arrangement that satisfies the definition

of a heliostat yet has a mirror motion that is 2/3rd of the motion of the sun. For want of abetter term, I have called this a 2/3rd motion heliostat.

Many other types of heliostat have also occasionally been used. In the very earliest

heliostats, for example, which were used for daylighting in ancient Egypt, servants or slaves

kept the mirrors aligned manually, without using any kind of mechanism. (There are placesin Egypt where this is done today, for the benefit of tourists.) Elaborate clockwork heliostats

were made during the 19th Century which could reflect sunlight to a target in any direction

using only a single mirror, minimizing light losses, and which automatically compensated forthe sun's seasonal movements. Some of these devices are still to be seen in museums, but

they are not used for practical purposes today. Amateurs sometimes come up with ad

hocdesigns which work approximately, in some particular location, without any theoretical

justification. An essentially limitless number of such designs are possible.
http://en.wikipedia.org/wiki/Daylightinghttp://en.wikipedia.org/wiki/Daylighting


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OPERATION

The main aim of our project is to maximize the power output generated by the solar

panel using microcontroller

Firstly we have to switch on the microcontroller by using the power stored in the

battery

This microcontroller samples the output of the solar cell to detect maximum power

Stepper motor is having rotating motion which converts into oscillating motion by

means of beam engine principle

This stepper motor gets power from battery which stored previously in it

The oscillating motion provides to solar panel to absorb the solar energy from the sun

The output power generates from the solar panel will displayed on the LCD display

Microcontroller test the output using the program given to it

The microcontroller is programmed based on embedded C


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The instructions given to it based on maximum cut-off range of power generation

If the radiation of the light is below 9 volts then the solar panel will rotate

continuously to track the maximum solar energy under the sun light

If the LCD display shows 9volts then the solar panel stops rotating and fixed in that

position

The power generated by means of photovoltaic process

Photovoltaic is the direct conversion of light into electricity at the atomic level.

Sunlight is composed of photons are particles of solar energy

When these photons strike a photovoltaic cell they may be reflected, pass light

through or be absorbed

Only the absorbed photons provide energy to generate power

This generated power is stored in the battery bank which is used for several purposes

PERFORMANCE CALCULATION

for example,

in Kavali, latitude angle,

on may 10th

, day of the year, n = 31+28+31+30+10 = 130

at 10:30 AM, hour angle, = +22.5

declination angle, = 23.45

= 23.45

= 17.5164

For horizontal surfacess=0, = z zenith angle

Cos z = sin sin + cos cos cos


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38

= sinsin 17.5164 + cos 17.5164 cos cos 22.5

= 0.9288

z=

= 21.75

Also day length, td =

=

= 12.64 hours

= 12 hrs 38min 24 sec

In case of microcontroller

The amount of electricity developed per hour = 6watts

The amount of electricity developed Per day = 612.64

= 75.84 W

The amount of electricity developed Per month = 75.8430

= 2275.2 W

The 18 watts bulb is works =75.84/18

= 4.21 hrs

By convention, solar cell efficiencies are measured under standard test conditions

(STC).. STC specifies a temperature of 25 C and an irradiance of 1000 W/m2with an

air mass 1.5 (AM1.5) spectrum. These conditions correspond to a clear day with

sunlight incident upon a sun-facing 37-tilted surface with the sun at an angle of

41.81 above the horizon.[2][3]

This represents solar noon near the spring and autumn

equinoxes in the continental United States with surface of the cell aimed directly at

the sun. Under these test conditions a solar cell of 20% efficiency with a

100 cm2(0.01 m

2) surface area would produce 2.0W.

The microcontroller used power =320 mA

Motor required power = 12 volts

Totals power required for controller and motor = 120.320
http://en.wikipedia.org/wiki/Solar_cell_efficiency#cite_note-2http://en.wikipedia.org/wiki/Solar_cell_efficiency#cite_note-2http://en.wikipedia.org/wiki/Solar_cell_efficiency#cite_note-2http://en.wikipedia.org/wiki/Watthttp://en.wikipedia.org/wiki/Watthttp://en.wikipedia.org/wiki/Solar_cell_efficiency#cite_note-2http://en.wikipedia.org/wiki/Solar_cell_efficiency#cite_note-2


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= 3.84 watts

Then total power developed in solar panel = 75.84-3.84

= 72 W/day

Appliance Watts Appliance Watts Appliance Watts

Central Air Conditioner

NA5,000 Electric blanket 200 Hedge trimmer 450

Electric Clothes Dryer NA 3,400 Shaver 15 Weed eater 500

Oven 3,000 Waterpik 100 1/4 drill 250

Hair Dryer 1,538 Well Pump (1/3-1

HP)

480-

12001/2 drill 750

Dishwasher1200-

1500Laptop

60-

2501 drill 1000

Coffee Machine 1,500 Plasma TV 339 9 disc sander 1200

Microwave 1,500 LCD TV 213 3 belt sander 1000

Popcorn Popper 1,400 25 color TV 150 12 chain saw 1100

Toaster oven 1,200 19 color TV 70 14 band saw 1100

Hot Plate 120012 black and

white TV20

7-1/4 circular

saw900

Iron 1,100 Stereo 10-308-1/4 circular

saw1400

Toaster 1,100 Satellite dish 30 Refrigerator/Freezer**

Microwave500-

1500

Radiotelephone

Receive5 20 cu. ft. (AC)

1411 watt-

hours/day*


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40

Room Air Conditioner NA 1,100Radiotelephone -

Transmit

40-

15016 cu. ft. (AC)

1200 watt-

hours /day*

Vacuum Cleaner 500 Lights Freezer

Water heater 479100 watt

incandescent bulb100

15 cu. ft.

(Upright)

1240 watt-

hours /day*

Sink Waste Disposal 45025 watt compact

fluor. bulb28 15 cu. ft. (Chest)

1080 watt-

hours /day*

Espresso Machine 36050 watt DC

incandescent50

Cell Phone

recharge2-4 watts

Dehumidifier 350 40 watt DChalogen

40 MP3 Player recharge

.25-.40watts

Blender 30020 watt DC

compact fluor.22

* TVs,VCRs and other

devices left plugged in, but not

turned on, still draw power.

**To estimate the number of

hours that a refrigeratoractually operates at its

maximum wattage, divide the

total time the refrigerator is

plugged in by three.

Refrigerators, although turned

"on" all the time, actually

cycle on and off as needed to

maintain interior temperatures.

Humidifier300-

1000

CFL Bulb (60-

watt equivalent)18

Video Game Player 195

CFL Bulb (40-

watt equivalent) 11

Standard TV 188CFL Bulb (75-

watt equivalent)20

Monitor 150CFL Bulb (100-

watt equivalent)30

Computer 120 Heaters***

Portable Fan 100Engine Block

Heater NA

150-

1000

Ceiling Fan 100Portable Heater

NA1500


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41

Can Opener 100Waterbed Heater

NA400

Curling Iron 90Stock Tank

Heater NA

100

Stereo 60 Furnace Blower300-

1000

Cable Box 20Clothes Dryer -

Gas Heated

300-

400

Clock Radio 7Well Pump (1/3-

1HP)

480-

1200

Table 5.1

WELDING

7.1 ARC WELDING

Arc welding is one of several fusion processes for joining metals. By applying intense

heat, metal at the joint between two parts is melted and caused to intermix - directly, or more

commonly, with an intermediate molten filler metal. Upon cooling and solidification, a

metallurgical bond is created. Since the joining is an intermixture of metals, the final

weldment potentially has the same strength properties as the metal of the parts. This is in

sharp contrast to non-fusion processes of joining (i.e. soldering, brazing etc.) in which the

mechanical and physical properties of the base materials cannot be duplicated at the joint.


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42

7.1 The basic arc-welding circuit

In arc welding, the intense heat needed to melt metal is produced by an electric arc.

The arc is formed between the actual work and an electrode (stick or wire) that is manually

or mechanically guided along the joint. The electrode can either be a rod with the purpose of

simply carrying the current between the tip and the work. Or, it may be a specially prepared

rod or wire that not only conducts the current but also melts and supplies filler metal to the

joint. Most welding in the manufacture of steel products uses the second type of electrode.

7.1.1BasicWeldingCircuit

The basic arc-welding circuit is illustrated in Fig. An AC or DC power source, fitted

with whatever controls may be needed, is connected by a work cable to the work piece and

by a "hot" cable to an electrode holder of some type, which makes an electrical contact with

the welding electrode.

An arc is created across the gap when the energized circuit and the electrode tip

touches the work piece and is withdrawn, yet still with in close contact.

The arc produces a temperature of about 6500F at the tip. This heat melts both the

base metal and the electrode, producing a pool of molten metal sometimes called a "crater."

The crater solidifies behind the electrode as it is moved along the joint. The result is a fusion

bond.

7.1.2ArcShielding

However, joining metals requires more than moving an electrode along a joint. Metals


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43

at high temperatures tend to react chemically with elements in the air - oxygen and nitrogen.

When metal in the molten pool comes into contact with air, oxides and nitrides form which

destroy the strength and toughness of the weld joint. Therefore, many arc-welding processes

provide some means of covering the arc and the molten pool with a protective shield of gas,

vapor, or slag. This is called arc shielding. This shielding prevents or minimizes contact of

the molten metal with air. Shielding also may improve the weld. An example is a granular

flux, which actually adds deoxidizers to the weld.

7.1.2 This shows how the coating on a coated (stick) electrode

provides a gaseous shield around the arc and a slag covering on the

hot weld deposit.

Figure illustrates the shielding of the welding arc and molten pool with a Stick

electrode. The extruded covering on the filler metal rod, provides a shielding gas at the pointof contact while the slag protects the fresh weld from the air.

The arc itself is a very complex phenomenon. In-depth understanding of the physics

of the arc is of little value to the welder, but some knowledge of its general characteristics

can be useful.

7.2 SOLDERING

Solder is an alloy of tin and lead used for using metals relatively low temperature

about 260-315k the point where two metal conductors are to be fused is heated and then

solder is applied so that it can melt and cover the connection. The reason for soldering

connection is that it makes a good blend between the joined metals.


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44

Covering the joint completely is to prevent oxidation. The coating of solder provides

protection for practically an in definitive period of time. The trick in soldering is to heat the

joint, not the solder. When the joint is not enough to melt the solder the cracks, forming a

shifty cover without until the solder has set, which takes only a few seconds. Either a

soldering gun can be used, rated at 25-10,000. The gun is convenient for the intermittent

operation, since it heats almost instantaneously when for press the trigger. The small pencil

iron of 25-4,000 is helpful or small connections where excessive heat can cause damage.

This precaution is particularly important when working on PCB boards, where too much heat

can soften the plastic form and loosen the printed writing, a soldering iron for F&T devices

should have the tip ground to eliminate static charge. The three grades of solder, generally

used for electronics work are 40-60, 50-50, 60-40 solder. The 60-40 solders costs more but it

melts at the lowest temperature flows more freely takes less time to harder, and generally

makes it easier to do a soldering job. In addition to the solder there must be flux to move any

oxide film on the metals being joined otherwise they cannot fuse. The flux enables the

molten solder to wet the metals so that the solder can stick. The two types are acid flux and

rosin flux. Acid flux is more active in cleaning metals but is corrosive. Rosin flux is always

used for the light soldering work in making wire connection.

ADVANTAGES AND APPLICATIONS

1. Pollution free atmospheric condition due to the absence of smokes and fumes.

2. They have a long effective life.

3. They are highly reliable

4. They are working with freely available solar energy, hence fuel cost is zero.

5. Operating cost, maintenance costs are minimum as compared to the other type

of power generation systems.

6. They have wide power handling capability from Microwatts to Kilowatts or

even Megawatts. When modules are combined into large arrays. Solar cells

can be used in combination with power handling circuitry to feed power into

utility grid.

7. They have high power to weight ratio, this characteristic is more important for

space applications than terrestrial. For example the roof loading (or a house


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45

roof is covered with Solar cells), would be significantly lower than the

comparable loading for a conventional liquid solar water heater.

8. They can be installed easily in the required site without any power loss due to

transmission and costs of transmission lines are eliminated.

RESULTS

Solar cell produces electricity under the sunlight during the day

CONCLUSION

The project aids the conservation of the conventional fuel by partially using

the solar energy as described in the project work.

The main objective, to increase the usage of renewable energy source forpower generation is perfectly implemented. Taking into consideration the

future energy scenario in the world, solar energy would be a major energy

source.

REFERENCES

Non-conventional sources of Energy

By G.D. Rai

Solar Power Engineering

- By B.S. Magal

Solar EnergyThe Infinite source


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- By G.K.Ghosh

Direct Solar production of Electricity

- By Dr.L.W. Davies

Solar Energy

- HP. Garg

J. Prakash

Solar Engineering

- Duffee and Beckman

solar tracker project

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