presentation chennai science centre

7/29/2019 Presentation Chennai Science Centre

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Chennai Science Festival 2013

BIODIVERSITY & FOOD SECURITY

Anna Gem Science Park School

Chennai

1 February 2013

Dr. A. Jagadeesh

Head R & D

Centre for Energy and Sustainable ResourcesR.M.K. Engineering College

KAVARAIPETTAI 601 206

Tamil Nadu

E-mail: [email protected]


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Energy from the Sun

About half the incoming solar energy reaches the Earth's

surface.

The Earth receives 174 petawatts (PW) (1015 watts) of

incoming solar radiation at the upper atmosphere.

Approximately 30% is reflected back to space while the rest isabsorbed by clouds, oceans and land masses.

Earth's land surface, oceans and atmosphere absorb solar

radiation, and this raises their temperature. Sunlight

absorbed by the oceans and land masses keeps the surface

at an average temperature of 14 C.

By photosynthesis green plants convert solar energy

into chemical energy, which produces food, wood and

the biomass from which fossil fuels are derived.


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Yearly Solar fluxes & Human Energy Consumption

The total solar energy absorbed by Earth's atmosphere, oceansand land masses is approximately 3,850,000 exajoules (EJ) (1018

joules) per year. (70% of incoming sunlight) (1 Joule = energy

required to heat one gram of dry, cool air by 1 C)

Primary energy use (2005) 487 EJ (0.0126%)

Electricity (2005) 56.7 EJ (0.0015%) Therefore a good target

2002, more energy in one hour than the world used in the year.

Photosynthesis captures approximately 3,000 EJ per year in

biomass.

The amount of solar energy reaching the surface of the planetis so vast that in one year it is about twice as much as will ever be

obtained from all of the Earth's non-renewable resources of coal,

oil, natural gas, and mined uranium combined.

As intermittent resources, solar and wind raise issues.


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Solar Cells Background

1839 - French physicist A. E. Becquerel first recognized the

photovoltaic effect. Photo+voltaic = convert light to electricity

1883 - first solar cell built, by Charles Fritts, coated

semiconductor selenium with an extremely thin layer of gold to

form the junctions.

1954 - Bell Laboratories, experimenting with semiconductors,

accidentally found that silicon doped with certain impurities was

very sensitive to light. Daryl Chapin, Calvin Fuller and Gerald

Pearson, invented the first practical device for converting sunlight

into useful electrical power. Resulted in the production of the firstpractical solar cells with a sunlight energy conversion efficiency of

around 6%.

1958 - First spacecraft to use solar panels was US satellite

Vanguard 1


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PV Solar for Electricity

Photovoltaic's For the 2 billion people without access to electricity, it would be

cheaper to install solar panels than to extend the electrical grid.

(The Fund for Renewable Energy Everywhere)

Providing power for villages in developing countries is a fast-

growing market for photovoltaics. The United Nations estimates

that more than 2 million villages worldwide are without electric

power for water supply, refrigeration, lighting, and other basic

needs.

A one kilowatt PV system* each month: Prevents 150 lbs. of coal from being mined

Prevents 300 lbs. of CO2 from entering the atmosphere

Keeps 105 gallons of water from being consumed

Keeps NO and SO2 from being released into the environment


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Morphology of solar cells


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... a house, but also with very large

systems that then is connected via a ...


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Solar Street Lights


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Hybrid Solar and Wind


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Solar Lights


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Solar Reading Lamps


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Solar Cap


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Solar Safety Helmet


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Solar Fan


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Solar Key Chain Mobile Charger


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Solar key ring


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Amorphous Solar Panel Torch Lights


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Solar-Powered Radio Headphones


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Solar Car Race


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Solar Car


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Solar Boat


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Solar Aeroplane


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Is it a Bird, Is it a Plane? No, it's the new Com-Bat Solar Powered Spy ...


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SOLAR TOWER POWER PLANT Solar Two in Barstow, California,


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At Abengoa Solar's facility in Spain, mirrors heat a liquid in a tower, ...


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Tower of Power


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There is fresh news about the Gema solar tower.


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... is then used as heat or as a heat source for a conventional power plant ...


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Solar Chemistry. Two-axis tracked parabolic trough collectors concentrate ...


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It takes a large number of parabolic dish assemblies to make a practical ...


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Over 4,400 solar PV panels will span the bridge


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Dahanu PV solar power plant in Jaisalmer district of Rajasthan has started ...


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Solar Pump


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Put the SUN to WORK: To getinexhaustible,pollution-free energy

which cannot be misused


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