What is the Need of Alternate

Sources of Energy?

The social, economic and scientific developmentof a country are directly linked to its energyresources. The conventional sources ofenergy that are being used for a long time, aregenerally non renewable. They include coal,petroleum, natural gas and electricity. We areusing them so extensively that their reservesare depleting at a fast rate. At the same time, itis becoming increasingly difficult to discovernew deposits. Keeping this in mind, there areattempts all over the world to tap alternativesources of energy.

This Include energy from sun, wind, tides,geothermal sources, biomass and even fromwastes. These forms of energy are abundant,renewable, pollution free and ecofriendly. Theycan also be conveniently made available inurban, rural and even remote areas. Use of non-conventional forms of energy can serve twopurposes.

Supply of energy in a decentralized system. Sustaining a cleaner environment

Solar energySun provides us enormous amount of energy in the form of solar

radiation. It reaches the Earth from a distance of about 150million kilometers, in the form of small wave packets calledphotons. It is the result of continuous thermonuclear fusiontaking place in the sun.

1. Conversion of solar energy into heat energySolar energy falling on the surface of the earth can be converted

into thermal energy. The heat generated can be stored in Solarcollectors. It can be utilized for various purposes such asheating of water and cooking of food.

2.Conversion of solar energy into electrical energy It uses the principle of photo voltaic effect. Such a device is called

solar cell. You have seen such solar cells being used in thetraffic signals in cities, lighting lamps and pumping water and forother purposes in rural areas.

SOLAR POND

Solar Pond is one of the most promising technology inharnessing solar energy. It is a large scale solar collectorwith an integrated arrangement for storage of heating energy.

Working : You know that water and air become lighter and riseabove, when heated. When water is heated by solarradiation, hot water form the bottom of the pond rises andreaches the surface. It loses the heat gained, to theatmosphere. The result is that pond water remains at atemperature nearer to that of the atmosphere. This loss ofheat is prevented by dissolving salts in the bottom of thepond. It makes water denser and hence, it cannot rise to thesurface. Thus solar energy remains trapped in the pond.

Bio energyIncludes those processes where biological mattersuch as plants and plant products provide the basisfor energy and its conversion. Plant, organicmatter, also called vegetable biomass, offers cleanfuel for energy.

Bio alternative to dieselThe oil extracted from the seeds of the plant,Jatropha is now being used as a bio alternative todiesel. It requires the conversion of crude oil fromthe seeds to a commercially usefull fuel. Thisprocess is called trans estrerification.

Wind energy is the kinetic energy associatedwith the movement of large masses of air,resulting from the differential heating ofatmosphere by the sun.

Wind turbines are used

for the purposes of

obtaining wind energy.

Wave energy

Movement of large quantities of water upand down in the seas and oceans, in theform of waves is also a source ofenergy.

However, the cost of energy conversionper unit, is very high, since it requiresmany special equipments to be creatednear the sea. Wave energy is howevermore reliable than wind energy since thefluctuations are comparatively lesspronounced.

It refers to heat of the Earth within 10km.

from the surface. Geothermal energy has a

temperature of about 13000C.

There are about 340 hot springs identified in

different parts of our country. Of these, only

a few have been used.

Energy from wastes

A huge quantity of waste is generated in our townsand cities. Waste generation is very high,especially in sugar, paper and pulp industries.Such wastes can also be converted into energy.

Biogas is a clean, unpolluted and

inexpensive source of energy for rural areas.

It contains nearly 70% of methane, an

inflammable gas. It is produced from cow

dung in a specific biogas plant commonly

called gobar gas plant. It helps in obtaining

both cooking fuel and enriched manure. It

can also be used for lighting and running

small engines.

How is biomass converted into energy ?

There are three basic processes involved in theconversion of biomass into energy sources.

Combustion pyrolysis: It is a process of chemicaldecomposition at high temperature (as high as50000c) in total or partial absence of air. It yields fuelgas, ethanol and charcoal.

Bio gasification : It is a process of anaerobicdigestion of biomass to produce a combustible gascalled biogas, containing methane and hydrogen.

Fermentation: Conversion of sugars into alcohol toproduce ethane and solid residual fuel.

CONCLUSION

Thus in the recent years search foralternative sources of energy hasyielded good results. If they areproperly put into use, we can beself sufficient and can look towardssustainable development.

Know this Facts:The amount of solar energy reaching per square meter ofEarth’s atmosphere is called solar constant. It is equivalentto 1.36 kw in 12 hours of time. Energy being received in theatmosphere is about 1.5 x 1018 kwh per day

Pongamia pinnata (Honge) is another plant that yieldsbiofuel.

Government of Karnataka has a scheme to encouragefarmers to grow Jatropha in their field during lean periods ofagriculture. The seeds of the plant are purchased by thegovernment, to extract oil.

The largest installation of wind turbines in the country arefound near Kanya Kumari in Tamil Nadu

Jatropha is a hardly plant which can grow on any type ofsoil, under any kind of agro-climatic conditions. The plantcan easily be propagated through seeds or stem cuttings. Itgrows very fast. Moreover, it is not grazed by animals evenduring periods of drought.