This continuously changing world of ours which is goingthrough a technological advancement process every moment needs a better andeverlasting power source as solar energy. Sun, a sphere of hot plasma is thestar center of solar system, and the provider of solar energy is one of themost important sources of energy available to earth. The acceptance of solarenergy as the energy for the greener future has been confirmed by thescientists all over world. Developed countries of the world have alreadyinvested in modernizing the technology for making solar energy more applicablefor the future.Solar energy sustains an important position among all therenewable energy sources available. Though, solar energy comes with a highercost of conversion but abundant supply makes it reliable to proceed. Investmentin the development of solar energy will have longer time benefits on issueslike lowering the cost of managing global warming, reducing pollution and moreimportantly unlimited power source.
Planet earth absorbs approximately 3850000 EJ per year. This number isabout two times higher than the amount of energy can be obtained from of allnon-renewable combined at once. In order to turn this huge solar power intousable electric power, we need modify existing technology into more advancestate or we have to invent new technology. Solar power is the converted sunlight into electricity through the direct process Photovoltaic in short PV orthe indirect one, Concentrated Solar Power in short CSP. PV is method we use onrooftops of houses or offices. This method converts light into electric energyusing photoelectric effect. CSP uses lenses or mirrors and advanced trackingsystem to concentrate a large area of sunlight into a small beam and use ituses it as a heat source of a conventional power plant.
There is also a hybridsystem which operates by using the main principles of these two forms. Forgeneral people, PV is more convenient for everyday use at present and all thetechnology for renewable energy sources it more frequently seen all over theworld.Technological developmentis an ongoing process for solar power. Solar power usage has come a long wayfrom warming water in households to lighting bulbs. In households people usesolar panels, which is an outcome of PV technology. The solar panels consistedof solar cells converts lights into electricity.
First solar cell was inventedby Charles Fritts in 1880. German Engineer Bruno Lange developed a photo cellusing silver selenide in 1931. His prototype was not cost efficient as itconverted less than 1% light to electricity. In 1954, Gerald Pearson, CalvinFuller and Daryl Chapin created silicon solar cell which had efficiencies of4.5%-6% at the unit cost of $286.Mordern PV system produces DC power byrippling with the sunlight’s intensity. For practical use this needed to beconverted into AC current by a converter.
Multiple modules are wired togetherto produce power at desired condition maintain required voltage, frequency andphase. CSP is form which is more industrial usable than residential. Stirlingdishand, compact linear Freshnel relector, parabolic through are some of bestknown concentration technologies available.
There are various techniquesavailable to track and focus light. These systems use heated working fluids bythe sun to generate power. Thermal storage efficiency allows up to 24 hourelectricity generation. In this method a parabolic through is used. This isconsisted of a liner parabolic reflector that concentrates light onto areceiver. This receiver is a tube positioned along the focal points of thelinear parabolic mirror and is filled with a working fluid. This reflectorfollows the sun by tracking along a single axis. Parabolic through systemsprovide best land use factor of any solar technology.
From the early developmentof solar power technology to present world, the humanity and science have comea long way in search of knowledge and advancement. Solar energy researchprimarily started with an expectation that coal would soon become scarce.Electrification with solar energy is much more efficient and therefore leads toa significant reduction in primary energy requirements; because most renewablesdon’t have a steam cycle with high losses (fossil power plants usually havelosses of 40 to 65%).But now it is not only about insufficiency of fuel. If wewant to live in a greener, prosperous, healthy world, we must invest our laborand money on solar energy, which is unlimited free and environment friendly.