solar photo voltaics

Seminar onBasic Design Principles And Components of

Solar Photo-voltaic

K.SumalathaAssistant ProfessorDepartment of EEEKUCE&TKakatiya University

SOLAR•Energy from the sun• Energy from the sun renewable•Solar energy is a direct form of renewable energy•All other renewable energies (like wind, bio-mass,bio-gas and geothermel) are derived from solar energy •PV-cell :which is a method of harnessing the colossal quantum of solar energy

An electric utility produces electricity at a power plant and distributes it to consumers through power lines, substations, and transformers.

Distributed generation systems produce electricity close to where it is used.

Solar Energy applications3 Categories:

•Direct Thermal application

•Energy from wind

•Solar Electric applications -Photo voltaic conversion

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Path of energy conversionsun light

optical concentration

high temperature thermal energy

thermodynamic engine

electricity generator

sun light

solar cell

electricity

sun light

wind energy

rotor

generator

electricity

Energy conversion through solar cell is simple

Solar electric power generation• The direct conversion of solar energy in to electrical

energy by means of “photovoltaic effect”

•photovoltaic effect-Generation of an electromotive force as a result of absorption of ionizing radiation

• Energy conversion devices used to convert sunlight to electricity by photovoltaic effect are called as ‘Solar cells’

Solar cells

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What is solar cell?

Solar cells

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Solar cell is a two terminal power generating device, one is a positive (anode) terminal and the second is a negative terminal (cathode)

What is solar cell?

Single solar cell

Solar cellsWhat is solar cell?

What does solar cell do?

Solar cell is a two terminal power generating device, one is a positive (anode) terminal and the second is a negative terminal (cathode)

Single solar cell

Solar cells

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What is solar cell?

A solar cell directly converts sunlight into electricity

What does solar cell do?

Solar cell is a two terminal power generating device, one is a positive (anode) terminal and the second is a negative terminal (cathode).

Single solar cell

Sunlight into Electricity

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No sunlight No electricity

Sunlight into Electricity

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Sunlight Electricity

Angle at which day light falls ()

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Sunlight absorption is maximum for sunlight falling perpendicular to the surface of a solar cellMaximum electricity is generated when = 90°

= 90° R* = 0 90° R* 0

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What solar cell should do? Solar cell should generate voltage or potential (which can drive current through a load)

The potential is said to be developed when a positive charge is separated by negative charge in space

+ -V

A solar cell must first generate positive and negative charge carriers and then it must separate them

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Principle of solar thermal energy conversion(light to heat conversion)

Continuous band gapEnergy

SpacePrinciple of solar PV energy conversion (light to photo-voltage conversion)

Separated band gap

Separation of opposite charges

results in potential difference

Energy

Space

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+

+

++- -

--

Photo Voltaic cell

Electrode

P-Type SemiconductorN-Type SemiconductorReflect-Proof Film

Electrode

Solar Energy

Load

Elec

tric

Cur

rent

• Mechanism of generationThe solar cell is composed of a P-type semiconductor and an N-type semiconductor. Solar light hitting the cell produces two types of electrons, negatively and positively charged electrons in the semiconductors.Negatively charged (-) electrons gather around the N-type semiconductor while positively charged (+) electrons gather around the P-type semiconductor. When you connect loads such as a light bulb, electric current flows between the two electrodes.

n-type semiconductor

p-type semiconductor

+ + + + + + + + + + + + + + + - - - - - - - - - - - - - - - - - -

Physics of Photovoltaic Generation

Depletion Zone

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•Direction of current inside PV cell

P

N

Current appears to be in the

reverse direction ?

?

• By Solar Energy, current is pumped up from N-pole to P-pole.

• In generation, current appears reverse. It is the same as for battery.

P

N

Looks like reverse

Solar PV module

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Solar PV module

A solar PV module is a device in which several solar cells are connected together to generate more power than a single solar cell.

Single solar cell

Solar Cell to Solar PV Module Why ?

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Series connection Voltage is additive

Single solar cell power = 2.5 Watts

6 cells in series connection 15 Watts

Solar PV module

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A solar PV module is a device in which several solar cells are connected together to generate more power than a single solar cell.

Different typesof PV modules

Solar PV module

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A solar PV module is a device in which several solar cells are connected together to generate more power than a single solar cell.

Different typesof PV modules

Energy flow in PV systems

For designing a PV systems, each component in the path of energy flow should be considered Consideration for specifications, efficiency, rating, autonomy, etc.

Battery is considered in the design for non-sunshine hour load operation

Load(AC /DC)

Energy storage(Typically batteries)

Electronic control circuit( Charge controller, DC to AC converter)

PV module

•Solar radiation•PV-array•Inverter•Battery storage•loads

Photovoltaic System

Typical output of a module (~30 cells) is ≈ 15 V, with 1.5 A current

Present PV Scenario in India• In terms of overall installed PV capacity,

India comes fourth after Japan, Germany and U.S.

(With Installed capacity of 110 MW)

• In the area of Photovoltaic's India today is the second largest manufacturer in the world of PV panels based on crystalline solar cells.

(Industrial production in this area has reached a level of 11 MW per year which is about 10% of the world’s total PV production)

30% increase in global manufacturing of solar cells every year

Expected Future of Solar Electrical Capacities

Solar Resource Map of India

• Arid regions receive plentiful solar radiation, regions like Rajasthan, Gujarat and Haryana receive sunlight in plenty.

Thus the Potential availability - 20 MW/km2

Solar PV advantages and disadvantages:

Applications @ PV• Water Pumping: PV powered pumping systems are

excellent ,simple ,reliable – life 20 yrs• Commercial Lighting: PV powered lighting systems are

reliable and low cost alternative. Security, billboard sign, area, and outdoor lighting are all viable applications for PV

• Consumer electronics: Solar powered watches, calculators, and cameras are all everyday applications for PV technologies.

• Telecommunications• Residential Power: A residence located more than a

mile from the electric grid can install a PV system more inexpensively than extending the electric grid (Over 500,000 homes worldwide use PV power as their

only source of electricity)

Solar PV modules used for rural electrification

Solar Roof tiles(Solar Grants now available)

Integrated solar tiles installed by Solar Century on a current development in Milton Keynes by English partnership and Bloor homes

Roof mounted solar panels (Solar century)

Innovative SunSlates installation by Solar century for Liang Homes

6.1 kW thin film solar PV module

Street Lighting

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Grid connection

A Step towards achieving the Vision

The Delhi Government has decided to make use of solar power compulsory for lighting up hoardings and for

street lighting

“ By the year 2030, India should achieve Energy Independence through solar power

and other forms of renewable energy ”

Dr. A. P. J. Abdul Kalam

President of India Independence

Day Speech,2005

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Challenges to PV technology• High cost per unit watt (high cost of material)

• Moderate efficiencies

• Availability of material

• Long term stability

• Long energy pay back period (high processing cost)

• Long money pay back period

CONCLUSION

Even though initial cost of installation is high it is a friendly technology (not generates any pollution) for production of electricity with low maintenance.

Thank You