Solar Energy as the Answer to the Energy Crisis - Coursework Example

Running Head SOLAR ENERGY, THE ANSWER Solar Energy, The Answer to the Energy Crisis The sun’s energy which is available to us free , is the best alternative to the diminishing fossil fuel which has become a major problem. Being pollution free, solar energy will reduce the green house gas emissions into the atmosphere. In spite of its disadvantages, solar energy is the energy source of the future. Solar Energy, the Answer to the Energy Crisis When in March 1930, Mahatma Gandhi led his followers to make salt out of sea water in India using the sun’s energy, his action rang the death knell for the greatest empire on earth of the time. By using solar energy, Gandhi’s ‘Salt March’ , the first organized act of civil disobedience against British rule, finally brought independence to India by non-violent methods. The sun’s energy has been used by humans since the dawn of history for different purposes. Ancient people of Egypt, Mesopotamia, India and Greece considered the sun to be a god. The sun was also considered to be a deity by Zoroastrians, the Druids, the Buddhists and many native American tribes To warm, to dry, to live, solar energy has been used in many ways throughout human existance, The caveman used the heat of the sun to keep himself warm, and the twenty first century man also uses solar energy , whether it is in the form of coal or electric fire, for the same purpose. Clothes are dried, salt is made and food is cooked using solar energy. Plants use solar energy efficiently to manufacture food, and animals eat plants. Thus, whatever food we eat is indirectly made using the sun’s energy. Without the sun there would be no life on the earth. Coal and petroleum which provide us fuel, were made billions of years ago by plants and animals using solar energy. Being non-renewable sources of energy, they are going to be exhausted in the foreseeable future at the rate we are using them. The imperative need of the day is to find an alternate source of energy in place of the non-renewable fossil fuels. Among the alternate sources of energy available to us, solar energy is arguably the best. The sun’s energy that is pounding the earth is put into varied uses by man. People living in the west coast of India, where there is incessant rain for four months during the monsoons, use the abundant solar energy they receive before the advent of the rainy season to dry vegetables and other food stuffs so that they do not become moldy. One can see terraces of houses spread with drying jackfruit, pieces of drying green mango, turnip and cauliflower. Fishermen preserve fish by drying it in the sun. The Chinese have perfected the art of using the sunlight to preserve fruit. Sunlight is also used to heat water. Solar water heaters were very popular in the U.S.A in the 1890’s. They disappeared when cheap fossil fuels became available everywhere. The sun’s energy has been used since time immemorial to make salt from sea water. Among other things, it is used to purify water, to burn things and to dry laundry. In parts of Africa and India, pats of cowdung is dried in the sun to be used later as fuel. In modern times solar energy was originally developed to power the satellites which orbit round the earth. Arrays of solar panels were used to power the satellites. With the rising cost of petrol and fears of its erratic supply, people have started going in for solar energy for domestic use. Now houses are being powered by solar energy. According to a report in the Scientific American, two enormous solar farms are being built in California which will be fully operational by 2013. They would provide, according to the report, 1.65 billion kilowatt hours of electricity per annum, which is sufficient for the energy needs of 239,000 homes in California. Countries like Morocco, and Spain which have abundant sunlight, are going in for solar energy in a big way.(Scientific American Oct 20, 2008) Solar energy can be used in a passive way or an active way. In a sunny climate, passive solar heating is the best solution to heating the house. Passive solar heating, though it is comfortable in winter, can cause discomfort in summer. This can happen even in the northernmost latitudes. It is better to reduce the solar gain in the summer months.(Balcomb,Solar Energy Houses p.6) In a Yosemite house in the U.S.A, the domestic hot water is heated by a heat pump by cooling the house. In the Rottweil house in Germany, the house is cooled by ground ventilation. In summer, the house ventilation is drawn to the basement beneath the house, thus cooling the house. The Japanese house uses active solar heating. Hybrid PV collectors are installed to improve the efficiency. Air heated by the PV panels is used as a source of heat.(Balcomb, Solar Energy Houses p7) . The energy in sunlight which strikes the earth for forty minutes is enough to meet the energy needs of all the countries of the earth for one year. Countries which receive a lot of sunlight in a year are in an advantageous position than the countries in the far north who do not receive sufficient sunlight. The term used for the incoming solar radiation striking a surface at a particular time is insolation. According to Solar Energy International, on a clear day, the total insolation striking the earth is around 1000 watts per square metre. Solar radiation striking the earth is affected by the variations in the atmospheric condition at that place. To power a house with solar energy, it is best to use photovoltaic cells. The PV modules should point towards the true south in the northern hemisphere. They should be inclined at an angle equal to the latitude of the place., so that they absorb the maximum energy throughout the year.(Hestnes, 27) Care should be taken to ensure that no trees or buildings shade the system at any time during the day. This is very important because even if one cell out of the thirty six cells of the module is shaded, then the electricity generated will be reduced by more than fifty per cent. If energy is to be stored, then batteries would have to be used. Since the life of batteries are much shorter than the PV modules, it is better to get connected to a grid. You can sell power when it is in excess and buy energy from the grid when you want extra energy. Remember that the selling rate is always less than the buying rate. Wherever batteries are used, they must be maintained. The electricity generated by a PV system is direct current, while electricity supplied to houses is alternate current. Some modules have a built in inverter which overcomes the problem. Solar energy is the preferred source of energy for industrial applications in remote areas. It is much more economical than conventional energy in those cases. It is used for giving power to repeater stations for microwave, television and radio. It is also the energy of choice for telemetry and radio telephones. Being cost effective, solar energy is used for off-shore navigation buoys, lighthouses, aircraft warning lights and road traffic warning signals. The advantages of solar energy outweigh the disadvantages The most important advantage of solar energy is the cost. After the initial expenditure in setting up the PV system has been recovered, the energy you receive is completely free. The energy transmitted by the sun is free and in constant supply. Being practically inexhaustible, it does not need any fuel. Hence it is not affected by vagaries of the supply and demand. Unlike petroleum, its price does not increase constantly. You can even make money by selling your excess energy to the grid. It is not only free and inexhaustible, it can earn you money too! Besides being free, solar energy has another advantage Most governments offer financial subsidies and incentives to the solar energy producer, which helps to bring down the cost. Since those who produce more energy than they need can store it or sell it to the grid., the savings from solar energy are immediate, and they will continue for many years as maintenance of the equipment is quite cheap. Solar energy is cost effective because it reduces your hospital bills. Since there is no pollution, there are no pollution related health hazards. Moreover, since it is so cheap, people, especially senior citizens will not hesitate to use the energy to keep their homes warm. This will bring down the rate of sickness due to cold and exposure which elderly people are prone to. Another major advantage of solar energy is that it is environmentally friendly. Being clean and renewable, it helps to protect the environment unlike coal, oil or gas. Generating electricity from solar energy does not pollute the atmosphere by emissions of green house gases like carbon dioxide and sulphur dioxide nor is there emissions of mercury , which the traditional methods of electricity generation do. This means that solar energy does not contribute to global warming, acid rain or the hole in the ozone layer. In fact, it actively contributes to the protection of the environment. Since electricity is generated where it is needed, there is no problem of transportation. Cables need not be laid over long distances to convey it, nor fuel need be shipped to the place. This way, there is enormous reduction of cost. Unlike in the case of nuclear power generating facility, there is no radio-active waste to be stored when we produce electricity using solar energy. It can be used in far flung and remote areas. There is no need for transportation, pollution by trucks and other vehicles is reduced. Forests need not be cleared for transport . Another major advantage of solar energy is that it can operate independently, as it does not require a connection to petrol, gas or electric supply. Thus it is eminently suited for use in remote locations, like holiday resorts, log cabins or far flung islands. It is more cost effective for industries in remotr areas to install a PV system than get connected to the grid. Solar energy creates jobs for the people in remote areas , thereby enhancing their economic independence. The use of solar energy reduces our dependence on the central grid. The country’s needs are met and we need not buy power from foreign countries. When we depend on foreign sources of power, we are not in an enviable position as the sources may be affected by natural or political events. Constructing solar farms is a reliable way to supply all the people sufficient energy at reasonable rates, for many years. An important aspect of solar energy which will gladden the hearts of all home makers is that there is no hassle of maintenance. The PV systems do not need any maintenance and will work satisfactorily for years. After the initial installation cost , there is no recurring cost. If, after some years, you want more energy, then more PV panes can be added to the existing system. Since there are no moving parts in the system, nothing gets worn out. If the system is connected to the grid, even the cost of battery maintenance is eliminated. Solar panels do their work in silence. They do not release any odour. Since they do not irritate the people around by sound or smell, they increase the general efficiency and harmony. Solar energy has some disadvantages too, the most important being the capital cost of installing the PV systems. The materials such as semiconductors which are used are expensive. Since fossil fuels are cheaper, people still prefer to use petroleum products. Research is being done in many countries to reduce the cost of solar energy. Although the PVmodules last for twenty years without maintenance, the batteries have a much shorter life and they need frequent maintenance. Besides, the electricity generated is direct current while the electricity supplied to the house is alternate current. To overcome this problem, an inverter has to be used. Some PV modules have a built in inverter. Another major drawback is that solar energy fades when the sun sets. Any change in the weather will affect the energy output, as the PV cells must have uninterrupted sunlight to work efficiently. Shade reduces the energy output drastically. This disadvantage can be overcome by using batteries to store the energy, and to design the house in such a way that the module gets the maximum sunlight during the day. Shade from nearby buildings has to be avoided, which is a challenge in designing a house in an urban area. Power generating plants must adjust to this fact by utilizing solar thermal energy during peak hours. Solar energy needs enormous areas of land as solar panels require large areas to work efficiently.. It is not advisable to use fertile agricultural land for solar power generation plant either. Therefore it becomes necessary to identify vast tracts of barren land for the purpose, which have usually sunny weather throughout the year and are not affected frequently by the vagaries of the weather.According to a report in the Scientific American,{Oct 20,2008), countries like the U.S.A and the northern African countries have already identified and have begun work on building solar farms. New architectural designs are being used to increase the efficiency of the systems. The United States in planning to use enormous areas in its south west to build huge solar energy farms which will be operational in a few years. It hopes to produce enough energy for its needs by 2050, so that its dependence on fossil fuels is reduced to a minimum. North Africa, with its abundant sunshine and vast areas of land in its desert, is making plans to install hybrid solar thermal plant. Egypt, Istael, Algeria and Jordan are also building Solar thermal plants. The rate of energy conversion to electrical energy are low in solar thermal plants as well as in PV cells compared to other energy sources. Increasing research and development is being done in this field, which, it is hoped, will improve the energy conversion rate in the near future. In spite of all its disadvantages, solar energy has some great advantages like inexhaustibility, low cost and availability which make it a viable source of cheap energy .Being completely pollution free, it will reduce the global green house gas emissions and thus reduce the speed of the climate change. There is no doubt that solar energy will be the preferred energy source of the future. References Energy Quest: California Energy Commission . Last updated 22 April 2002 http://energyquest.ca.gov/story/index.html Balcomb, D.J..”Strategies” in Solar Energy Houses : Strategies, Technologies, Examples. Earthscan. 2003.ed. Hestnes, A.G., Hastings R., Saxhof Hirschmann., Kris. Solar Energy Amazon . com Klein,S.L. Power to Change the World Amazon.com Hestnes, A.G., Hastings R., Saxhof.,B. Solar Energy Houses : Strategies, Technologies, Examples. Earthscan. 2003. Whelan, Carolyn.( 2008 October 20.) “Is the Sun Setting on Solar Power in Spain?” Scientific American. . Read More