solar photovoltaic system for rural electrification in india

Photovoltaic

Power System

INDIA 2011-14

SOLAR RADIATION:

SOURCE OF LIGHT ENERGY

FOR DIRECT CONVERSION

TO ELECTRIC POWER

SOLAR CELL: TO CONVERT

SUNLIGHT DIRECTLY TO

ELECTRICITY

TYPES OF PV MODULES

BALANCE OF SYSTEM:

Inverter, Controller, Battery

etc.

PV SYSTEM COMPONENTS

AND FUNCTIONS OF

COMPONENTS

APPLICATIONS

SOLAR RADIATION SOURCE OF LIGHT ENERGY

FOR

CONVERSION TO ELECTRICITY

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Insolation in India: An Energy Resource

Solar radiation is perennial,

environment-friendly and well suited

for decentralized applications.

Most parts of India receive 4–7 kWh

(kilowatt-hour) of solar radiation per

square metre per day.

There are 250–300 sunny days in a

year.

The highest annual radiation energy is

received in western Rajasthan.

SOLAR CELL SUNLIGHT CONVERSION TO ELECTRICITY

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TYPES OF PV CELLS

AND

MODULES

Module

Every single photovoltaic cell has small

dimensions and generally produces a

power between 1 and 3 watts and 0,5Volts,

at the standard test conditions (STC) of

1000W/m².

To get a bigger power and voltage, it is

necessary to connect several cells among

themselves to create bigger units called

modules

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The modules in a PV array are usually first

connected in series to obtain the desired voltage;

the individual strings are then connected in

parallel to allow the system to produce more

current. They are then protected by

encapsulation between glass and a tough metal,

plastic or fiberglass back. This is held together by

a stainless steel or aluminum frame to form a

module.

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These modules, usually comprised of about 30

PV cells, form the basic building block of a solar

array. Modules may be connected in series or

parallel to increase the voltage and current, and

thus achieve the required solar array

characteristics that will match the load. Typical

module size is 50Wp and produces direct current

electricity at 12V (for battery charging for

example).

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PV SYSTEM COMPONENTS

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The photovoltaic system structures

• Systems with fixed inclination - (fixed

supporting structure)

• Systems with active tracking - single/double

axis tracking systems (characterized by step by

step motors and control electronics)

• Self contained systems or “stand alone”

• Network connected systems or “grid

connected”

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Applications of Solar PV Systems

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Solar Lantern

• The solar lantern is a portable lighting system. Being light in weight, it is easy to carry around and therefore ideal for both indoor and outdoor usage.

• A typical solar lantern consists of a PV module of 8 Wp to 10 Wp capacity, a sealed maintenance-free battery of 12 V, 7 AH (ampere hours) capacity, and a compact fluorescent lamp (CFL) of 5 W or 7 W rating. A solar lantern is usually meant to provide light for three to four hours daily, and designed to have a three-day

„autonomy‟, that is, to function in this manner for

three days without sunlight.

58 Operation:

During the day, the PV

module is placed in the sun

and is connected through

a cable to the lantern unit.

LIGHT is converted into

electricity, which, in turn,

charges the battery. A

green LED light indicates

the charging of the battery.

At night, the lantern is

detached and used

wherever required. The

battery provides power to

the lamp.

The cost of a solar

lantern with the above

specifications is in the

range of Rs 3000–3300.

Low-cost models with

smaller PV modules

and battery capacity

are also available.

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Solar home system -1

A solar home system (SHS) provides a

comfortable level of illumination in one or

more rooms of a house. There are several

SHS models featuring one, two, or four

Compact Fluorescent Lamps (CFL). It is also

possible to run a small DC fan or a 12-V DC

television with the system.

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Solar home system - 2

The SHS consists of a PV module of 18, 37 or

74 Wp (Watt peak) capacity; a sealed,

maintenance-free, or flooded lead–acid

battery of 12 V and 20, 40 or 75 AH capacity;

and CFLs of 9 W or 11 W rating.

The system is designed to provide service

for three to four hours daily, with an

autonomy of three days, that is, the system

can function for three cloudy days.

61 Operation

A PV module is usually mounted on the roof of the

house so that it is exposed to direct solar radiation

throughout the day, avoiding any

shadow.

The module converts incident radiation into

electricity, which, in turn, charges the battery,

which is placed inside the house.

The battery provides power to the CFLs, and to the

television and/or fan as required. A change

controller prevents overcharging and deep

discharge of the battery.

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Solar street lighting system

A solar street-lighting system (SLS) is an

outdoor lighting unit used to illuminate

a street or an open area usually in

villages. A CFL is fixed

inside a luminaire which is mounted on

a pole.

The PV module is placed at the top of

the pole, and a battery is placed in a

box at the base of the pole. The

module is mounted facing south, so

that it receives solar radiation

throughout the day, without any

shadow falling on it.

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A typical street-lighting system consists of a PV

module of 74 Wp capacity, a flooded lead–acid

battery of 12 V, 75 AH capacity, and a CFL of 11 W

rating. This system is designed to operate from dusk

to dawn (that is, throughout the night). The CFL

automatically lights up when the surroundings

become dark and switches off around

sunrise time.

The cost of an SLS is about Rs 19 000. Variations in the

cost are possible on account of local taxes,

additional transportation costs, etc.

The Ministry of New & Renewable Energy Sources

provides financial assistance for the promotion of

some of the above solar lighting systems among

eligible categories of users.

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SPV Pumping System

An SPV water pump is a DC or AC, surface-mounted or submersible or floating pump that runs on power from an SPV array.

The array is mounted on a suitable structure and placed in a shadow free open space with its modules facing south and inclined at local latitude.

A typical SPV water-pumping system consists of an SPV array of 200–3000 Wp capacity, mounted on a tracking/non-tracking type of structure.

The array is connected to a DC or AC motor connected to pump of matching capacity.

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• The array is connected to a DC or AC motor

connected pump of matching capacity that can be

of s u r f a c e - m o u n t e d , submersible, or

floating type. Interconnecting cables and

electronics make up the rest of the system.

• SPV water pumps are used to draw water for

irrigation as well as for drinking. The normal pumping

heads are in the range of 10 metres (m) for

irrigation, and 30 m for drinking water. It is possible

to use pumps with even greater head, especially for

drinking water supply. The SPV array converts

sunlight into electricity and delivers it to run the

motor and pump up water. The water can be stored

in tanks for use during non-sunny hours, if necessary.

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The SPV array converts sunlight into electricity and

delivers it to run the motor and pump up water. The

water can be stored in tanks for use during non-

sunny hours, if necessary. For maximum power

output from the SPV array, the structure on which it is

mounted should track the sun. Electronic devices are

used to do this in some models, thereby enabling the

systems to operate at maximum power output. The

power from the SPV array is directly delivered to the

pump in the case of DC pumps. In the case of AC

pumps, however, an inverter is used to convert the

DC output of the array into AC. No storage batteries

are used in an SPV pump.

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An SPV pump based on a one-horsepower motor

can irrigate about 1–1.5 hectares of land under a

variety of crops except paddy and sugar cane

(assuming a 10-m water table). Using the same

pump along with drip irrigation, it is possible to

irrigate up to 6 hectares of land for certain crops. A

two-horsepower SPV pump could irrigate about 2–3

hectares of land under many crops except paddy

and sugar cane (again assuming a 10-m water

table).

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SPV Pumping System

The cost of an SPV

pump depends on the

capacity and type of

pump. For example, a

DC surface pump with

a 900 W array may cost

about Rs 150 000; a

similar pump of 1800 W

may cost about Rs 300

000; and an 1800 W AC

submersible pump may

cost about Rs 422 000.

Sagar Island - Solar Island

Sagar Island is in the southwestern corner of the

Ganges Delta, in India. The West Bengal Renewable

Energy Development Agency (WBREDA) has been

working on Sagar Island since 1996 to address the

problem of energy supply. Since then it has set up a

total of 11 small solar PV power plants, on Sagar

Island and its neighbour Maushuni Island. Each plant

has its own mini-grid system that distributes electric

power to the surrounding villages. The grids are

switched on for six hours a day, from 6pm to

midnight, and are managed by cooperative

societies formed by the villagers that use the power.

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Sagar Island - Solar Island

The 11 power plants in operation supplying stable and

reliable 400 / 230V, 3 phase, 50Hz power for six to

seven hours a day through local distribution lines. The

combined capacity of the plants is 400Kw and

WBREDA estimates that a further 400Kw is needed in

order to electrify all the villages in the two islands.

Source: Ashden Trust Awards for Sustainable Energy

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SOLAR CELL & MODULE MANUFACTURERS IN INDIA

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Solar PV Projects News

PV Technologies India (a subsidiary of

Moser Baer), Titan Energy Systems,

Reliance Industries Ltd, Tata BP Solar Power

are among the 12 Solar Photo Voltaic

projects filed under Special Incentive

Package Scheme (SIPS), which have

received in-principle clearance from the

Government.

Together, these 12 projects would entail an

investment of Rs 76,500 crore over a 10-

year period.

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Indian Perspective-2010

JAWAHARLAL NEHRU NATIONAL SOLAR MISSION

BOOKS FOR STUDY &

REFERENCE SOLAR ELECTRICITY

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The Energy & Resources Institute, [TERI]

New Delhi

FROM SUNLIGHT TO ELECTRICITY A practical handbook on solar photovoltaic

applications

(Second Edition), 2010

ISBN 978-81-7993-156-1

TERI Press

TERI, Darbari Seth Block,

IHC Complex, Lodhi Road,

New Delhi 110 003

www.teriin.org

129

SOLAR ELECTRICITY

SOLAR ELECTRICITY,(second Edition), Edited

by Tomas Markvart, University of

Southampton, UK, John Wiley & sons, 2000

Contents

1 Electricity from the Sun

2 Solar Radiation

3 Solar Cells

4 Photo voltaic Engineering

5 Applications

6 Environmental Impacts of Photovoltaics

7 Advanced and Specialised Topics

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Reference books

S. Roberts: Solar Electricity – A practical guide to

designing and installing photovoltaic

systems. Prentice Hall, 1991.

G. Foley: Photovoltaic Applications in Rural Areas of

the Developing World. World Bank, 1995.

International Energy Agency Photovoltaic

Power Systems Programme

www.iea-pvps.org/

Useful websites

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http://www.pvpower.com/

Contains a wealth of information including PV glossary, bibliography, system

design software, PV standards, units and conversion factors, and environmental

safety and health

information

http://www.iea-pvps.org/ Web site of the Photovoltaic

Power Systems Programme of the International Energy Agency.

A wealth of information and IEA reports: many can be

downloaded from the site.

Newsletter of the IEA PVPS

programme can be found

at

http://www.oja-services.nl/iea-pvps/pvpower/home.htm




Solar electricity

138

Volume 6 of UNESCO energy

engineering series

UNESCO energy engineering

series: Energy engineering

learning package

Author T. Markvart

Editor T. Markvart

Edition 2, illustrated

Publisher John Wiley and

Sons, 2000

ISBN 0471988529,

9780471988526

Length 280 pages

Designing with solar power: a source book for

building integrated photovoltaics (BiPV)

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Designing with Solar Power is the result

of international collaborative research

and development work carried out

within the remit of the International Energy Agency's Photovoltaic Power

Systems Programme (IEA PVPS), where

world-wide and interdisciplinary

expert experience on building-

integrated photovoltaics has been

brought together .

140

Eastern Economy Edition books

1. SOLAR PHOTOVOLTAICS, Chetan Singh Solanki

Fundamentals, Technologies and Applications,

Second Edition, 2011

2. PHOTOVOLTAIC SYSTEMS, Analysis and Design

A.K. Mukerjee and Nivedita Thakur, 2011

Published by: PHI Learning pvt Ltd, New Delhi, 110001