19-11-2012, 01:33 PM
Renewable Energy Sources
1Renewable Energy.doc (Size: 249 KB / Downloads: 47)
ABSTRACT:
Today's crisis in the field of energy supplies, environmental control, population increase, poverty and shortage of food and materials are closely interrelated. It is gradually realized that they demand a holistic, systematic and integrated approach to deal with. Now we see that a 5 % yearly increase in the use of energy not only points to fuel depletion, but is also a main cause for increase in pollution level and related disasters. Too many ambitious single-purpose plans are made with little or no regard to the interdependent short and long-term social-economic and environmental effects, which has caused concern over the arising global environmental issues.
The present paper highlights the perspectives and some issues related to integrated renewable energy system. Though the global issues related to renewable energy are discussed here, the paper concentrates on the issues, which are more directly related to developing country like India.
INTRODUCTION:
Ever since 1973 oil crises, many countries have justifiably maintained an abiding interest in renewable energy sources and as a result many renewable energy programs were developed. Since then, research and development in the field were more promising and reliable. Main advantage of renewable energy is that its main ingredient is renewable and it plays crucial role in meeting environmental standards by combating global warming and other threats. At the current rate of energy consumption, the limited reserves of coal, oil, and gas may last only for 197, 40, and 56 years respectively. Our forests on the other hand are declining due to many reasons and recent studies show that firewood demand is not the only reason for forest degradation, though it contributes significantly. Environmental health of our planet is degrading and it is losing its ecological balance. Climate change, ozone depletion, acid rain, global warming, loss of biodiversity are some of the threats to be tackled if planet earth has to survive for long time. Energy issues are the focus of all these threats and therefore it needs special attention. Renewable energy sources promise to meet all the challenges, so as to attain the sustainable development
SOLAR ENERGY:
Energy from sun. The sun gives out 3.7 × 10^26 watt of power in to space, out of which the earth intercepted is equivalent to1.7 × 10^17 watt. Solar energy emitted by sun within three minutes is equal to the world energy consumption during a year. Photovoltaic (PV) panels use silicon cells, which transform solar radiation into direct current. The energy is used simultaneously (for example to pump water) or is stored in batteries to provide electricity. Solar energy can also be used to cook food by trapping and concentrating the sun's heat in a cooker, and to heat water or to generate steam which, in turn, can be utilized for mechanical applications. This is usually done by flat plate collectors which are exposing a large thin surface, containing a liquid, to the sun. The sun's heat can be intensified with lenses and mirrors and stored in salts and stones. Solar energy is still not viable on economic front to many developing countries therefore its use is promoted by various agencies. The World Bank has a program to install home lighting system in 200,000 homes to Indonesia. Of the 200 million Indonesian, 60 million people still rely on kerosene for lighting.
GEOTHERMAL ENERGY:
The earth’s core consists of hot lava generates heat. In some places earth’s crust is very thin layer and transfers heat to underground water. In this case the underground water gets boiled and comes out with high pressure from these evaporation can be collected used to turn the turbines to produce electricity. India has nearly 250 geothermal sources (80 at Himalaya, 170 at Peninsula). It is available at free of cost and environmental pollution is very less.
This is the energy which lies embedded within the earth. The geothermal energy has great potential and is already being commercialized in some developed countries. At present (end of1995) about 1500MW of power is being generated in the world from geothermal source. Geothermal over growth rate is accelerating, as more and more countries are exploring and evaluating their courses of earth heat. In India .Geothermal power plant of 1MW using hot spring
BIOMASS ENERGY:
Biomass includes residues from forestry, purpose-grown agricultural crops, trees and plant types, organic waste, agricultural residue, agro-industrial and domestic origin waste [sewage and municipal solid waste]. On a worldwide scale Biomass contributes about 12% to today's primary energy supply, rising between 40% and 50% in most developing countries. Biomass fuel obtained from purpose-grown energy crops as well as forests and agricultural waste are being used in power plants and it is very competitive in price and quality with fossil fuels.
CONCLUSION
Renewable energy sources include the sun, wind, water, geothermal energy and biomass.These renewable sources are all natural occurring elements. If these sources are utilized properly we can able to produce energy in large scale without disturbing earth’s nature and not making pollution.