22-09-2016, 10:54 AM
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INTRODUCTION
Solar energy is the energy produced directly by the sun and collected elsewhere, normally
the Earth. The sun creates its energy through a thermonuclear process . The process creates
heat and electromagnetic radiation.
Only a very small fraction of the total radiation produced reaches the Earth. The radiation
that does reaches the Earth is the indirect source of nearly every type of energy used today
. The radiation that does reach the Earth is the indirect source of nearly every type of
energy used today. The exceptions are geothermal energy, and nuclear fission and fusion.
Even fossil fuels owe their origins to the sun; they were once living plants and animals
whose life was dependent upon the sun.
Much of the world's required energy can be supplied directly by solar power. More still can
be provided indirectly. The practicality of doing so will be examined, as well as the
benefits and drawbacks. In addition, the uses solar energy is currently applied to will be
noted.
Due to the nature of solar energy, two components are required to have a functional solar
energy generator. These two components are a collector and a storage unit. The collector
simply collects the radiation that falls on it and converts a fraction of it to other forms of
energy (either electricity and heat or heat alone). The storage unit is required because of
the non-constant nature of solar energy; at certain times only a very small amount of
radiation will be received. At night or during heavy cloudcover, for example, the amount of
energy produced by the collector will be quite small. The storage unit can hold the excess
energy produced during the periods of maximum productivity, and release it when the
productivity drops. In practice, a backup power supply is usually added, too, for the
situations when the amount of energy required is greater than both what is being produced
and what is stored in the container
PHOTOVOLTAIC CELL
The term "photovoltaic" comes from the Greek (photo) means "light", and "voltaic", means
electric ,from the name of the Italian physicist “VOLTA "after whom a unit of electromotive
force, the volt is named.
The sun is a star made up of hydrogen and helium gas and it radiates an enormous
amount of energy every second .
A photovoltaic cell is an electrical device that convert the energy of light directly into
electricity by photovoltaic effect.
Photovoltaics is the field of technology and research related to the practical application of
photovoltaic cells in producing electricity from light, though it is often used specifically to
refer to the generation of electricity from sunlight. Cells can be described
as photovoltaic even when the light source is not necessarily sunlight (lamplight, artificial
light, etc.). In such cases the cell is sometimes used as a photodetector (for
example infrared detectors,detecting light or other electromagnetic radiation near the
visible range, or measuring light intensity.
The operation of a photovoltaic (PV) cell requires 3 basic attributes:
The absorption of light, generating either electron-hole pairs or excitons.
The separation of charge carriers of opposite types.
The separate extraction of those carriers to an external circuit.
In contrast, a solar thermal collector collects heat by absorbing sunlight, for the purpose
of either direct heating or indirect electrical power generation. "Photoelectrolytic cell"
(photoelectrochemical cell), on the other hand, refers either a type of photovoltaic cell
(like that developed by A.E. Becquerel and modern dye-sensitized solar cells or a device
that splits water directly into hydrogen and oxygen using only solar illumination.
Photovoltaic power generation employs solar panels composed of a number of solar
cells containing a photovoltaic material.
Materials presently used for photovoltaics include monocrystalline silicon, polycrystalline
silicon, amorphous silicon, cadmium telluride, andcopper indium gallium selenide/sulfide.
Due to the increased demand for renewable energy sources, the manufacturing of solar
cells and photovoltaic arrays has advanced considerably in recent years.
Solar photovoltaics is a sustainable energy source. By the end of 2011, a total of 71.1
GW had been installed, sufficient to generate 85 TWh/year.And by end of 2012, the 100
GW installed capacity milestone was achieved.
Solar photovoltaics is now, after hydro and wind power, the third most important
renewable energy source in terms of globally installed capacity. More than 100 countries
use solar PV. Installations may be ground-mounted (and sometimes integrated with
farming and grazing) or built into the roof or walls of a building (either building-integrated
photovoltaics or simply rooftop).
Driven by advances in technology and increases in manufacturing scale and sophistication,
the cost of photovoltaics has declined steadily since the first solar cells were
manufactured, and the levelised cost of electricity (LCOE) from PV is competitive with
conventional electricity sources in an expanding list of geographic regions. Net
metering and financial incentives, such as preferential feed-in tariffs for solar-generated
electricity, have supported solar PV installations in many countries.With current
technology, photovoltaics recoup the energy needed to manufacture them in 3 to 4 years.
Anticipated technology would reduce time needed to recoup the energy to 1 to 2 year.
PRINCIPLE OF PV CELL
Solar cell works on the principle of photovoltaic effect. Sunlight is composed of photons,
or "packets “of energy. These photons contain various amounts of energy corresponding to
the different wavelengths of light. When photons strike a solar cell, they may be reflected
or absorbed. When a photon is absorbed, the energy of the photon is transferred to an
electron in an atom of the cell (which is actually a semiconductor). With its new found
energy, the electron is able to escape from itsnormal position associated with that atom to
become part of the current in an electric
MANUFACTURING OF SOLAR CELLS
• Raw Materials: The basic component of a solar cell is pure silicon, which is not pure in
its natural state
• Purifying the silicon
• Making single crystal silicon
• Making silicon wafers i.e. making small small silicon crystal.
• Doping
oping is used to increase the strength of the material.
• The anti-reflective coating :It is a type of opticlal coating applied to the surface of lenses.
It improves efficiency.
• Encapsulating the cell
APPLICATIONS
• For low-power portable electronics, like calculators or small fans, a photovoltaic array
may be a reasonable energy source rather than a battery.
• In other situations, such as solar battery chargers, watches, and flashlights, the
photovoltaic array is used to generate electricity.
• Solar chargers can charge lead acid or Ni-Cd battery bank up to 48 V and hundreds of
ampere-hours (up to 400 Ah) capacity.
• For such type of solar chargers, generally intelligent charge controllers are used. A series
of solar cell array plates are installed separately on roof top and can be connected to
battery bank. Such arrangement can also be used in addition to mains supply chargers for
energy saving during day times.
• Most portable chargers can obtain energy from the sun only. Portable knob's are also
sold. Some, including the Kinesis K3, can work either way. Examples of solar chargers in
popular use include:
• Small portable models designed to charge a range of different mobile phones, cell
phones, iPods or other portable audio equipment.
• Fold out models designed to sit on the dashboard of an automobile and plug into the cigar
lighter, to keep the battery topped up whilst not in use.
• Torches, often combined with a secondary means of charging, such as a kinetic charging
system.
• Public solar chargers permanently installed in public places, such as parks, squares and
streets, which passersby can use for free
SOLAR MOBILE CHARGER UNIT
Portable Solar Mobile Charger for mobile phone can be charged with Sun light and
electrical power. It stores power from the sun and charge mobile phone,iPod,etc.
Solar cell phone chargers use solar panels to charge cell phone batteries. They are
an alternative to conventional electrical cell phone chargers and in some cases can be
plugged into an electrical outlet.
There are also public solar chargers for mobile phones which can be installed
permanently in public places such as streets, park and squares.
The model which is according to European Commission proclaimed as the first in the
world is the Strawberry Tree, public solar charger invented by Strawberry energy
Company. This solar station won the first place at "EU Sustainable energy week
(EUSEW) 2011" in the Consuming category.
Some models of cell phones have a built in solar charger and are commercially
available for GSM cellphone models.
Solar cell phone chargers come in different shapes and configurations including
folding and rotating types.
INTRODUCTION
Solar energy is the energy produced directly by the sun and collected elsewhere, normally
the Earth. The sun creates its energy through a thermonuclear process . The process creates
heat and electromagnetic radiation.
Only a very small fraction of the total radiation produced reaches the Earth. The radiation
that does reaches the Earth is the indirect source of nearly every type of energy used today
. The radiation that does reach the Earth is the indirect source of nearly every type of
energy used today. The exceptions are geothermal energy, and nuclear fission and fusion.
Even fossil fuels owe their origins to the sun; they were once living plants and animals
whose life was dependent upon the sun.
Much of the world's required energy can be supplied directly by solar power. More still can
be provided indirectly. The practicality of doing so will be examined, as well as the
benefits and drawbacks. In addition, the uses solar energy is currently applied to will be
noted.
Due to the nature of solar energy, two components are required to have a functional solar
energy generator. These two components are a collector and a storage unit. The collector
simply collects the radiation that falls on it and converts a fraction of it to other forms of
energy (either electricity and heat or heat alone). The storage unit is required because of
the non-constant nature of solar energy; at certain times only a very small amount of
radiation will be received. At night or during heavy cloudcover, for example, the amount of
energy produced by the collector will be quite small. The storage unit can hold the excess
energy produced during the periods of maximum productivity, and release it when the
productivity drops. In practice, a backup power supply is usually added, too, for the
situations when the amount of energy required is greater than both what is being produced
and what is stored in the container
PHOTOVOLTAIC CELL
The term "photovoltaic" comes from the Greek (photo) means "light", and "voltaic", means
electric ,from the name of the Italian physicist “VOLTA "after whom a unit of electromotive
force, the volt is named.
The sun is a star made up of hydrogen and helium gas and it radiates an enormous
amount of energy every second .
A photovoltaic cell is an electrical device that convert the energy of light directly into
electricity by photovoltaic effect.
Photovoltaics is the field of technology and research related to the practical application of
photovoltaic cells in producing electricity from light, though it is often used specifically to
refer to the generation of electricity from sunlight. Cells can be described
as photovoltaic even when the light source is not necessarily sunlight (lamplight, artificial
light, etc.). In such cases the cell is sometimes used as a photodetector (for
example infrared detectors,detecting light or other electromagnetic radiation near the
visible range, or measuring light intensity.
The operation of a photovoltaic (PV) cell requires 3 basic attributes:
The absorption of light, generating either electron-hole pairs or excitons.
The separation of charge carriers of opposite types.
The separate extraction of those carriers to an external circuit.
In contrast, a solar thermal collector collects heat by absorbing sunlight, for the purpose
of either direct heating or indirect electrical power generation. "Photoelectrolytic cell"
(photoelectrochemical cell), on the other hand, refers either a type of photovoltaic cell
(like that developed by A.E. Becquerel and modern dye-sensitized solar cells or a device
that splits water directly into hydrogen and oxygen using only solar illumination.
Photovoltaic power generation employs solar panels composed of a number of solar
cells containing a photovoltaic material.
Materials presently used for photovoltaics include monocrystalline silicon, polycrystalline
silicon, amorphous silicon, cadmium telluride, andcopper indium gallium selenide/sulfide.
Due to the increased demand for renewable energy sources, the manufacturing of solar
cells and photovoltaic arrays has advanced considerably in recent years.
Solar photovoltaics is a sustainable energy source. By the end of 2011, a total of 71.1
GW had been installed, sufficient to generate 85 TWh/year.And by end of 2012, the 100
GW installed capacity milestone was achieved.
Solar photovoltaics is now, after hydro and wind power, the third most important
renewable energy source in terms of globally installed capacity. More than 100 countries
use solar PV. Installations may be ground-mounted (and sometimes integrated with
farming and grazing) or built into the roof or walls of a building (either building-integrated
photovoltaics or simply rooftop).
Driven by advances in technology and increases in manufacturing scale and sophistication,
the cost of photovoltaics has declined steadily since the first solar cells were
manufactured, and the levelised cost of electricity (LCOE) from PV is competitive with
conventional electricity sources in an expanding list of geographic regions. Net
metering and financial incentives, such as preferential feed-in tariffs for solar-generated
electricity, have supported solar PV installations in many countries.With current
technology, photovoltaics recoup the energy needed to manufacture them in 3 to 4 years.
Anticipated technology would reduce time needed to recoup the energy to 1 to 2 year.
PRINCIPLE OF PV CELL
Solar cell works on the principle of photovoltaic effect. Sunlight is composed of photons,
or "packets “of energy. These photons contain various amounts of energy corresponding to
the different wavelengths of light. When photons strike a solar cell, they may be reflected
or absorbed. When a photon is absorbed, the energy of the photon is transferred to an
electron in an atom of the cell (which is actually a semiconductor). With its new found
energy, the electron is able to escape from itsnormal position associated with that atom to
become part of the current in an electric
MANUFACTURING OF SOLAR CELLS
• Raw Materials: The basic component of a solar cell is pure silicon, which is not pure in
its natural state
• Purifying the silicon
• Making single crystal silicon
• Making silicon wafers i.e. making small small silicon crystal.
• Doping
oping is used to increase the strength of the material.• The anti-reflective coating :It is a type of opticlal coating applied to the surface of lenses.
It improves efficiency.
• Encapsulating the cell
APPLICATIONS
• For low-power portable electronics, like calculators or small fans, a photovoltaic array
may be a reasonable energy source rather than a battery.
• In other situations, such as solar battery chargers, watches, and flashlights, the
photovoltaic array is used to generate electricity.
• Solar chargers can charge lead acid or Ni-Cd battery bank up to 48 V and hundreds of
ampere-hours (up to 400 Ah) capacity.
• For such type of solar chargers, generally intelligent charge controllers are used. A series
of solar cell array plates are installed separately on roof top and can be connected to
battery bank. Such arrangement can also be used in addition to mains supply chargers for
energy saving during day times.
• Most portable chargers can obtain energy from the sun only. Portable knob's are also
sold. Some, including the Kinesis K3, can work either way. Examples of solar chargers in
popular use include:
• Small portable models designed to charge a range of different mobile phones, cell
phones, iPods or other portable audio equipment.
• Fold out models designed to sit on the dashboard of an automobile and plug into the cigar
lighter, to keep the battery topped up whilst not in use.
• Torches, often combined with a secondary means of charging, such as a kinetic charging
system.
• Public solar chargers permanently installed in public places, such as parks, squares and
streets, which passersby can use for free
SOLAR MOBILE CHARGER UNIT
Portable Solar Mobile Charger for mobile phone can be charged with Sun light and
electrical power. It stores power from the sun and charge mobile phone,iPod,etc.
Solar cell phone chargers use solar panels to charge cell phone batteries. They are
an alternative to conventional electrical cell phone chargers and in some cases can be
plugged into an electrical outlet.
There are also public solar chargers for mobile phones which can be installed
permanently in public places such as streets, park and squares.
The model which is according to European Commission proclaimed as the first in the
world is the Strawberry Tree, public solar charger invented by Strawberry energy
Company. This solar station won the first place at "EU Sustainable energy week
(EUSEW) 2011" in the Consuming category.
Some models of cell phones have a built in solar charger and are commercially
available for GSM cellphone models.
Solar cell phone chargers come in different shapes and configurations including
folding and rotating types.