Solar Energy The Ultimate Renewable Resource

PPT PRESENTED BY

T.V.N.VASISTA &P.M.N.SANKAR

Present EnergyResources

• Fossil fuels - coal, oil, gas are all of limited amounts. Cant be replaced.

• Nuclear fuels -limited amounts of uranium for nuclear fission reactors but reprocessing of fuel possible.

• Difficult to estimate how long these fuels will last - but is it sustainable economically or environmentally?

Sustainable situation• Renewable energy only resources are being

replaced / generated at the same rate that they are being utilised.

• All sources of energy ultimately come from the sun.• Diffrent Renewable energy resourses are • solar • wind • Geothermal• Agricultural and Forestry Wastes• Municipal and General Wastes• Hydro Power

What is Solar energy ?

Solar energy is simple energy provided by the sun This energy in the from of solar radiation,which makes the production of solar electricity simply: SOLAR : SUN ENERGY:POWERSOLAR + ENERGY=SUN POWER Solar energy is environment friendly and freely available locally

What is solar radiation ?

• Solar radiation is the radiation or energy we get from the sun .it is also called asx short -wave radiation .it comes in many forms such as visible light ,radio waves ,x-rays,uv rays.

• Working principle of solar cell

Sunlight is composed of photons, or bundles of radiant energy. When photons strike a PV cell, they may be reflected or absorbed (transmitted through the cell). Only the absorbed photons generate electricity. When the photons are absorbed, the energy of the photons is transferred to electrons in the atoms of the solar cell.

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• Solar cells are usually made of two thin pieces of silicon, the substance that makes up sand and the second most common substance on earth.

• One piece of silicon has a small amount of boron added to it, which gives it a tendency to attract electrons. It is called the p-layer because of its positive tendency.

• The other piece of silicon has a small amount of phosphorous added to it, giving it an excess of free electrons. This is called the n-layer because it has a tendency to give up negatively charged electrons.

How much solar energy?

The surface receives about 47% of the total solar energy that reaches the Earth. Only this amount is usable.

How Does it Work?

Solar Cooking

Consumes no fuels/wood

Generates no air pollution

Generates no greenhouse gases

Produces no smoke

Eliminates fire dangers

Benefits of Solar Cooking

solar energy applications

Solar Water Heating

• Actually, the first solar water heating collector appears to have been built in the 18th Century by a Swiss scientist who constructed a simple wooden box with a glass top and a black base

. Solar water heating is the most efficient and economical use of solar energy

Solar electricity generationSolar cells

• convert light into a small electrical output -milliwatts output.

• need a bank/array of cells for useful output.

• cost of cells is high but reducing.• efficiency of cells is up to 23%/

improving.• are situated on roof of building.

• .

Power tower in Barstow, California.

FUTURE OF SOLAR !

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The house of the future?

This zero-energy house and buildings

Photovoltaics on BuildingsPhotovoltaics on house

Decentralized

Energy efficient house; wind power on roof. Solar panels for heat and electricity.

you may be picturing something like this solar array used by the space shuttle to provide for power needs in outer space. There are people who think that solar energy is something not quite down-to-earth and not ready to use today.

Let’s begin our overview of solar energy by asking:

What do you see here?

Take a close look – is this the profile of a

beautiful young lady, or the face of an ugly, old woman?

They’re both here, but for a variety of reasons that make up your own individual psychological make-up, some of you see one woman, some the other.

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When people think of solar energy, the same thing often happens. Some see it as something for the future, others see it as something that is here today.

advantages• pollution free, indefinitely sustainable.• long life and easy to install• it can be usedin remote areas wheeit is too expensive to

extend the electricity powergriddisadvatages• Sun does not shine consistently.• Crystalline silicon-more efficient, more expensive to

manufacture• Addressed by approaching the problem through:

1) collection, 2) conversion, 3) storage.

What will that energy source be?

The answer ought to be obvious.

It’s been up there all the time

Solar energy will certainly play an importan but it’s also here today and ready for hundreds of uses in homes,businesses, and industry.

THE END

Solar Energy – A Bright Idea!

“I’d put my money on the sun and solar energy. What a source of power! I hope we don’t have to wait ‘til oil and coal run out before we tackle that.”

- Thomas Edison

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