ALTERNATE SOURCES
SOLAR ENERGY
Solar energy is energy that comes directly from the sun. The sun is a constant natural source of heat and light, and its radiation can be converted to electricity using solar panels.
Sun is the primary source of energy. It lights our houses by day, dries our clothes and agricultural produce, keeps us warm and lots mote. Its potential is however much larger.
Advantages
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SOLAR ENERGY is a INEXHAUSTIBLE source of energy.
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It is NON-POLLUTING source of energy.
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Solar powered lights and other Solar powered products are very easy to install.
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SOLAR CELLS are long lasting and require very little maintenance.
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It is a perennial, natural source, and free
Disadvantages
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SOLAR ENERGY is EXPENSIVE source of energy. Initially, requires high investments for the productive use
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DIFFUSED sourc, so gets wasted.
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It is not directly available at NIGHT or under CLOUD COVERED AREAS.
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SOLAR panels require quite a large area for installation to achieve a good level of efficiency
Technologies for productive use of solar energy
Solar energy can be used to generate electricity. Through Solar Photovoltaic (SPV) cells, solar radiation gets converted into DC electricity directly. The generated electricity can either be used as it is or can be stored in the battery. The stored electrical energy can be used when solar energy is not available. SPV is nowadays successfully used for home and street lighting and water pumping in villages. In hilly areas, solar water heating is also being used.
Some facts
THE FOLLOWING are some ways of using solar energy...
1. Solar water heater: 24-hour hot water supply. Returns in three years: 100 to 1,000 litre capacity.
2. Solar lantern: Once charged, it can be carried anywhere. Needs no maintenance.
3. Solar domestic lighting system: Two lights will burn for eight hours. No maintenance costs. Definite savings on electricity bills. .
4. Solar street lights: A 17-foot non-rusty pole. Burns for 12 hours a day. Automatic switch on and off.
5. Solar water pumps.
Wind
Wind is the natural movement of air across the land or sea.
Ø Conversion of wind energy to other forms of energy such as electricity is known as wind power.
Ø This is done using wind turbines.
Ø The three-bladed wind turbine is the most common
and modern design
The wind when used to turn the blades of a wind mill turns the shaft to which they are attached. This movement of shaft through a pump or generator produces electricity. Its estimated that India has the potential to produce about 45000MW. India now has the 5th largest wind power installed capacity in the world which has reached 1870 MW. Private agencies own 95 % of the wind farms in India.
Advantages
* It is
environment
* Its freely and abundantly available
Disadvantages
* High
investment requirement
* Wind speed is not uniform all the time which affects power generated.
Tidal Energy
• Tides are generated through a combination of forces exerted by the gravitational pull of the sun and the moon and the rotation of the earth.
• The relative motion of the three bodies produces different tidal cycles which affect the range of the tides.
• In addition, the tidal range is increased substantially by local effects such as shelving, funnelling, reflection and resonance
• Energy can be extracted from tides by creating a reservoir or basin behind a barrage and then passing tidal waters through turbines in the barrage to generate electricity.
• Tidal energy is extremely site specific requires mean tidal differences greater than 4 metres and also favourable topographical conditions, such as estuaries or certain types of bays in order to bring down costs of dams etc.
Tidal energy produced in waters
• Tidal energy is produced through the use of tidal energy generators.
• These large underwater turbines are placed in areas with high tidal movements, and are designed to capture the kinetic motion of the ebbing and surging of ocean tides in order to produce electricity.
• Tidal power has great potential for future power and electricity generation because of the massive size of the oceans.
• These articles explore the potential energy of tidal power technologies
BIOMASS
"Biomass" describes, in one word, all plants, trees and organic matter on the earth. Biomass is a renewable source of energy because the natural process of photosynthesis constantly produces new organic matter in the growth of trees and plants. Photosynthesis stores the sun's energy in organic matter. Biomass is used to make heat, electricity and liquid fuels.
The plants fix solar energy through the process of photosynthesis to produce biomass. This biomass passes through various cycles producing different forms of energy sources. For example, fodder for animals that in turn produce dung, agricultural waste for cooking. The current availability of biomass in India is estimated at about 120-150 million MT per annum covering agricultural and forestry residues corresponding to a potential of 16,000 MW.
Usage
Biomass is an important source of energy accounting for about one third of the total fuel used in our country and in about 90% of the rural households. The widespread use of biomass is for household cooking and heating. The types of biomass used are agricultural waste, wood, charcoal or dried dung.
Advantages
· Available locally and to some extent abundantly
· It is a relatively clean fuel when compared to fossil fuels. In a way biomass also cleans our environment by trapping Carbon di-oxide
· Usable fuel from manure and waste water treatment plant.
· Usable bi-products from the biogas process.
· Reduces greenhouse gas emission
· Sustainable resources as long as we have animals and waste water treatment plants.
· Low cost and easy to operate.
Disadvantages
· Drudgery involved in collection of fuel
· During indoor cooking and in the absence of sufficient ventilation fuels such as dung cause air pollution which is a serious health hazard.
Technologies that enable efficient use of biomass are becoming prevalent in rural areas in India.
The efficiency of fuel usage is increased by
· use of improved designs of stoves which double the efficiency such as smokeless energy efficient chulhas.
· compressing the biomass to form briquettes which not only occupy lesser space but also are more efficient.
· conversion of organic matter into biogas through anaerobic digestion which apart from meeting fuel needs also gives digested manure for farms.
- conversion of biomass into producer gas through partial combustion of biomass under controlled air supply
Biofuels
Biofuels are predominantly produced from biomass feed stocks or as a by-product from the industrial processing of agricultural or food products, or from the recovery and reprocessing of products such as cooking and vegetable oil. Biofuel contains no petroleum, but it can be blended at any level with petroleum fuel to create a biofuel blend. It can be used in conventional healing equipment or diesel engine with no major modification. Biofuel is simple to use, biodegradable, non-toxic and essentially free of Sulphur and aroma.
Water
The flowing water and the tides in the sea are sources of energy. Hydel energy contributed to 26% of emery consumption in the power sector during 2005. Heavy investments are made on large projects. In recent years, hydel energy is also used to reach power to remote villages which are unelectrified through mini and small hydel power plants. The estimated potential of Small Hydro Power is about 15,000 MW in the country. In the last 10-12 years, the capacity of Small hydro projects up to 3MW has increased 4 fold from 63 MW to 240 MW. 420 small hydropower projects up to 25MW station capacity with an aggregate capacity of over 1423 MW have been set up in the country and over 187 projects in this range with aggregate capacity of 521 MW are under construction.
Geothermal energy
Geothermal power (geo, meaning earth, and thermos, meaning heat) is energy generated from heat stored in the earth, or the collection of absorbed heat derived from underground.Geothermal literally means heat generated by earth. Hot springs which are prevailing in nature can serve as indictors for the presence of geothermal energy sources. Though there are over 300 hot springs sites in India, this form of energy is yet to be tapped.
Uses of geothermal energy
• Space heating
• Air conditioning
• Industrial processes
• Drying
• Greenhouses
• Aquaculture
• Hot water
• Resorts and pools
• Melting snow
Advantages
Ø Geothermal power requires no fuel
Ø Emissions free
Ø Low cost
Nuclear Power
• Nuclear power is obtained from energy stored in the nuclei of atoms of naturally occurring radio active elements like URANIUM and THORIUM.
• In India Rajasthan and Jharkhand have large deposits of Uranium.
• Thorium is found in large quantities in Monozite sands of Kerala.
Fuels like Uranium and Thorium undergo nuclear fission in nuclear reactors and emit power
Advantages
It emits large amount of energy.
Disadvantages
Generates radioactive waste which is harmful for our skin.
It is expensive.
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