Energy from Sunlight - Essay Example

Energy from Sunlight Abstract The sun’s energy which is freely available is the best alternative to the diminishing fossil fuel which has become a global problem. Solar energy is pollution free and hence will reduce the green house gas emissions into the atmosphere. Although there are some disadvantages in the use of solar energy, it is the energy source of the future. Energy from Sunlight The sun which is “one medium sized star among billions” (Bergamini p.85) has supported life since millions of years on its planet Earth. It has given energy and sustenance to the living things on the earth. Plants manufacture food using sunlight, and animals consume plants for sustenance. Carnivorous animals eat herbivorous animals .Thus the sun is the direct source of energy for the living beings on the earth. Man has made use of the energy of the sun since he came into existence. He uses solar energy for keeping himself warm, for heating, for cooking and for producing electricity. Fossil fuels such as coal and petroleum are getting depleted as they are non- renewable. Solar energy is the right alternative to the global energy crisis, as it is inexhaustible, abundant and free. The sun is a storehouse of enormous amount of energy. “Because we can measure the small share of sunshine that is actually intercepted by the earth, it is possible to calculate the total solar energy in all directions…. The sun is shining with a constant power of 380 million billion billion watts.”(Bergamini p. 87) The share of sunshine that the earth gets is more than enough to solve all the energy problems facing us. 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) Other countries are also looking at solar energy as an alternate source of energy. . 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 meter. (Solar Energy International) One of the ways to make use of solar energy is to use photovoltaic cells. The PV modules using arrays of PV cells is used to power a house. “. 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) According to TERI, an organization working for environmental concerns in India,” :Solar energy can also be used to meet our electricity requirements. Through Solar Photovoltaic (SVP) cells, solar radiation gets converted into DC electricity directly. This electricity can either be used as it is or can be stored in the battery. This stored electrical energy then can be used at night.”(TERI) The uses of the stored electricity generated using solar energy are many. Since it is stored, it can be used at night too. According to TERI, the stored solar energy can be used for “a.) domestic lighting. ,b.)street lighting, c)village electrification, d)water pumping, e)desalination of salty water, f) powering of remote telecommunications repeat stations and g)railway signals.” (TERI) 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. Power can be sold when it is in excess and bought from the grid when extra energy is needed .It must be remembered that the selling rate is always less than the buying rate. Wherever batteries are used, they must be maintained. Many countries have started using solar energy to augment their energy needs. According to a report in The Chronicle Herald of November 29, 2008, a town is Spain is making use of the space available in the cemetery to set up solar panels , because flat , open sun-drenched land is hard t come by in Santa Coloma de Gramenet. The report says, “The power produced by 462 solar panels is equivalent to the yearly use of 60 homes.” It flows into the normal energy grids, according to the report. The densely populated and built up city is making use of the cemetery to produce solar energy. The disadvantage of solar energy is that it can be produced only during the day. Another disadvantage is the high cost of the solar panels. According to a report in Los Angeles News, “UCLA researchers believe they have taken one step closer to creating high-efficiency solar cells using cheap plastic with a dash of silicon . “ (Los Angeles News) The report adds that the research team says it wants easy-to –use plastic solar energy cells to be sold at local hardware stores , and then hung like posters on the wall. We are facing the prospect of a global energy crisis triggered by non-availability of non-renewable fossil fuels. At this juncture, solar energy seems to be the best alternative. Many countries have already started using solar energy combined with conventional forms of energy. Although solar energy has some disadvantages, the benefits outweigh them. With more and more research taking place in different parts of the world, solar energy will surely become much cheaper. Countries which have large unpopulated and sunlit areas can directly benefit form converting to solar modules can use the PV modules and become more energy efficient. .Even individual houses Solar energy is the energy source of the future. Works cited Bergamini,David. The Universe, Time-Life Books, New York. 1971. Hestnes, A.G., Hastings R., Saxhof.,B. Solar Energy Houses : Strategies, Technologies, Examples. Earthscan. 2003. “Cheap High energy solar cells on the horizon” (2008, November 29) Los Angeles News. TERI website http://www.edugreen.teri.res.in/EXPLORE/renew/solar.htm Woolls, Daniel.(2008. November 29) The Associated Press. “Solar panels in cemetery power Spanish homes” The Chronicle Herald. Website http:// The ChronicleHerald.ca/Science/9009604.html Whelan, Carolyn.( 2008 October 20.) “Is the Sun Setting on Solar Power in Spain?” Scientific American. Read More