Solar Energy REPORT SUBTITLEName: abdulbasit Introduction: – Energy from the sun travels to the earth inthe form of electromagnetic radiation similar to radio waves, but in adifferent frequency range. Available solar energy is often expressedas energy per time per unit area, Joules per second per square meter, or watts persquare meter (W/m2). Theamount of energy available from the sun outside the Earth’s atmosphere isapproximately 1400 W/m2; that’s nearly the same as a high power hairdrier for every square meter of sunlight! Some of the solar energyis absorbed as it passes through the Earth’s atmosphere.
As aresult, on a clear day the amount of solar energy available at the Earth’ssurface in the direction of the sun depend of the angle of elevation and istypically only about 400 W/m2 in Canada. At any particulartime, the available solar energy is primarily dependent upon how high the sunis in the sky and current cloud conditions. On a monthly or annualbasis, the amount of solar energy available also depends upon thelocation. Furthermore, useable solar energy depends upon availablesolar energy, other weather conditions, the technology used, and theapplication involved. There are many ways that solar energycan be used effectively. Applications of solar energy use can begrouped into there are three primary categories: 1.Heating/cooling, 2.Electricity production, and 3.
Chemicalprocesses. The most widely used applications are for waterand space heating. Ventilation solar air heating is also growing inpopularity. Uptake of electricity producing solar technologies isincreasing for the applications photovoltaics (primarily) and concentratingsolar thermal-electric technologies. Due to recent advances in solardetoxification technologies for cleaning water and air, these applications holdpromise to be competitive with conventional technologies. Fig. 1: The energy budget of the Earth Historyusing Solar Energy & description in working: – Fig.
2: The Frenchchemist Lavoisier experimented with concentratingsolar energy using alarge parabolic mirror.Combustion, generated by focusing sunlight over flammablematerials using lenses, experiment conducted by Lavoisier circa 1770s. Fig.
3: In 1866, Auguste Mouchout used a parabolic trough toproducesteam for the first solar steam engine.Auguste Mouchout, inventor of thefirst active solar motor, questioned the widespread belief that the fossilfuels powering the Industrial Revolution in the 19th century would never runout. Prophetically he said:Eventually industry will no longer find in Europethe resources to satisfy its prodigious expansion. Coal will undoubtedly beused up. What will industry do then? In1861, Mouchout developed a steam engine powered entirely by the sun.
But itshigh costs coupled with the falling price of English coal doomed his inventionto become a footnote in energy history. Nevertheless, solar energy continued tointrigue and attract European scientists through the 19th century. Scientistsdeveloped large cone-shaped collectors that could boil ammonia to perform work likelocomotion and refrigeration. France and England briefly hoped that solarenergy could power their growing operations in the sunny colonies of Africa andEast Asia. Fig. 4: 1901 “solar motor” in operation in California. The solar furnace in Mont Louis, built in 1949 by Professor Félix Trombe, was the firstsolar furnace in the world. This dual reflection solar furnace has been insteady evolution over the past 50 years and in 1993, was taken over by thelimited liability company “Solar Furnace Development” who, along withcontinued scientific research, is the first company to use a solar furnace forindustrial and manufactured products such as the firing of ceramics, and bronzeand aluminum products.
ProfessorTrombelater (1969-1971) directed the design and the construction of the largestsolar furnace in the world that we will discuss in detail. Fig. 5: The solar furnace in Mont Louis. Sun power in the Pyrenees: – In 1972 Time magazine’s Sciencesection described the world’s largest solar furnace in sufficient technicaldetail to allow the setting for an investigation that involves a great deal ofstudents’ knowledge of physics and, with some guidance, can lead to her askinga series of questions that lead to problems and experimentation that go beyondthe textbook.
These questions eventually lead to the discussion radiation,optics, wave motion, thermodynamics, solar energy, quantum mechanics andthermonuclear reactions. It should also be mentioned that the Mont-Louis solarfurnace in the Pyrenees is still the largest in the world. Fig. 8: The Solar Furnace of Odeillo in the FrenchPyrenees.
(This is the largestsolar furnace in the world) Perched high in thePyrenees, France’spowerful new solar furnace (1970) harnesses the almost limitless energy of thesun. Eight stories tall, the furnace’sgleaming reflector dwarfs the ancient buildings nearby and turns thesurrounding hillsides topsy-turvy on its curved surface. Lined up in tiers on apasture in front of the big reflector stand 63 smaller mobile mirrors. These heliostats, as they are called, can beindividually adjusted so that each one reflects the sun’s rays directly intothe big parabola, thereby creating striking flare-ups of light. Focusing these rays at the oven building onlya short distance from its base, the giant mirror concentrates the sun’sradiation on the small target area. Theconverged beams, which are no wider than a foot at their target, can createtemperatures as high as 6,300° F (3500 °C.) Fig.
9: Three commonly used reflectingschemes for concentratingsolar energy to attain hightemperatures. The description of this context is based on an articlein Time magazine’s Science section that appeared in the May 18. 1970 issue. TheTime article describes the world’s largest (1970) solar furnace in sufficientdetail for an investigation that involves a great deal of the young physicsstudent’s knowledge of physics. The situations described below move from thepractical aspects of the furnace to a discussion of geometric optics,radiation, quantum theory, and thermonuclear reactions. Thefollowing is the content of the article as it was given in Time magazine.
A simple magnifying glass, focusing thesun’s rays, can scorch a piece of wood or set a scrap of paper on fire. Solar radiation can also be concentrated on amuch more awesome scale. It can burn ahole through thick steel plate, for example, or simulate the thermal shock of anuclear blast. It can, that is, with theaid of a super reflector of the sort that has been set up by French scientistshigh in the Pyrenees. Ten years in the building, the world’slargest solar furnace is a complex of nearly 20,000 mirrors and can concentrateenough sunlight to create temperatures in excess of 6,000° F, or 3500°C. Harnessing solar energy is hardly a newaccomplishment.
Nearly 22 centuries ago,the Greek mathematician Archimedes is said to have temporarily saved Syracuse from Romanconquest by setting the invading fleet aflame with numerous large mirrors. In the 18th century, the pioneerFrench chemist Lavoisier produced enough heat with 52-inch-wide lenses to powerhis experiments. Though Lavoisier’s work was cut short by the French Revolution(he was guillotined in 1794)), his history has not discouraged contemporaryFrench scientists—notably Physical Chemist Felix Trombe, a research director ofFrance’s National Center for Scientific Research and its premier experimenterwith the sun’s energy. For more than 20 years, Trombe haschampioned solar furnaces as an ideal source of intensive heat for bothindustrial uses and scientific experimentation. In 1946 he fashioned his first sun stove out of a captured Germanantiaircraft searchlight mirror at an observatory near Paris. Moving to the old Pyrenean citadel town of Mont-Louis where the sun shines as many as200 days a year, he has since built five larger solar furnaces. Now, in masterly style, he has created his pièce de résistance on a hillside in thenearby ski resort of Odeillo. Comparedwith similar devices in several other countries, such as the U.
S. Army’s30-kilowatt stove at Natick, Mass.,Odeillo’s 1,000-kilowatt structure is easily the Mount Palomar of solar furnaces. Fig.10: The Solar Furnace of Odeillo; Theparabolic shape of thegiantsolar collector is evident here. Fig. 11: The array of mirrors is controlled by a computer and turn withthe sun.
Rays come from reflectors Fig. 12: The geometry of reflection depend on the law of reflectivity Fig. 13: The furnace is located at the focus of the parabolic mirror Fig.14: The array of solar collector and the mirrors in perspective. Only recently, however, have we developed the ability to harnessthe sun’s awesome power. The resulting technologies have promising implicationsfor the future of renewable energy and sustainability.
Below, we’ve given abrief on solar power, how it works, and what may be in store for the future ofsolar.What is Solar Power?Solar power is a form of energy harnessed from the power andheat of the sun’s rays. It is renewable, and therefore a “green” source ofenergy. How Does It Work?The most common way of harnessing energy from the sun is throughphotovoltaic (PV) panels – those large, mirror-like panels you’ve likely seenon rooftops, handheld solar devices, and even spacecraft’s. These panelsoperate as conductors, taking in the sun’s rays, heating up, and creatingenergy (and electricity).
On a larger scale, solar thermal power plants also harness thepower of the sun to create energy. These plants utilize the sun’s heat to boilwater and, in turn, power steam turbines. These plants can supply power tothousands of people. . How is Solar Power a “Greener”Option?Just like wind power (link to blog), solar power is a virtuallyunlimited and inexhaustible resource (unlike power produced from expendablefossil fuels). As technologies improve and the materials used in PV panelsbecome “greener,” the carbon footprint of solar power becomes smaller andsmaller and the technique becomes more accessible to the masses.
What’s the Holdup? Why Isn’tSolar Power More Prevalent?Similarly, to wind power, solar power is contingent upon theweather and the amount of sunshine present in a specific location. This meansthat geographical areas lacking in sunlight, or areas that frequentlyexperience cloudy weather, may have difficulty utilizing solar powereffectively.Additionally, solar power is an expensive endeavor. Thetechnologies often require a large amount of land, and they can be extremelycostly. Scientists are hard at work to find an affordable, efficient solutionfor harnessing solar power.Did You Know?§ Every hour, the sun beats down with enough power to provideglobal energy for an entire year.§ It takes an average of eight minutes for energy to travelfrom the sun to the Earth.
§ Scientists have used solar energy to power spaceships since 1958.§ Most solar panels used today have an average life expectancyof between 20-40 years.Let the sunshine in! Interested in solar power for your home?There are a number of resources, projects, and products available online forfamilies interested in going solar. To get the best bang for your buck, be sureto conduct thorough research before beginning any new effort. Solar Energy Advantages: -Ø Saves you moneyØ After theinitial investment has been recovered, the energy from the sun ispractically free.
Ø Financialincentives are available from the government that will reduce yourcostØ Environmentfriendly Ø It’s notaffected by the supply and demand of fuel and is therefore not subjected to theever-increasing price of gasoline.Ø Solar energy isclean, renewable (unlike gas, oil and coal), sustainable and helping to protectour environment.Ø As we seepreviously, it does no pollute air.Ø Therefore, SolarEnergy does not contribute to global warming, acid rain or smog. it activelycontributes to the decrease of harmful greenhouse gas emissions. By not usingany fuel, solar energy does not contribute to the cost and problems of therecovery and transportation of fuel or the storage of radioactive waste.
Ø Low/nomaintenance.Ø Solar Energysystems are virtually maintenance free and will last for decades.Ø Once installed, there are norecurring costs. They operate silently, have no moving part, do not release offensivesmalls and do not require you to add any fuel. More solar panels can easily beadded in the future when your family’s needs grow. Disadvantages ofSolar Energy: -Ø Initial cost: theinitial cost of purchasing and installing solar panels always become the firstdisadvantage. Although subsidy programs, tax initiatives and rebate incentivesare given by government to promote the use of solar panels we are still waybehind in making full and efficient use of solar energy. Ø Location: the location of solar panels is ofmajor importance in the generation of electricity.
Areas which remains mostlycloudy and foggy will produce electricity but at a reduced rate and may requiremore panels to generate enough electricity homes. Houses which are covered bytrees, landscapes or other building may not be suitable enough to produce solarpower Ø Pollution: Most of the photovoltaic panels aremade up of silicon and other toxic metal like mercury, lead and cadmium.Pollution in the environment can also degrade the quality and efficiency ofphotovoltaic cells.
New innovative technologies can overcome the worst of theseeffects.Ø Reliability: Unlike otherrenewable source which can also be operated during night,solar panels prove to be useless during night which means you have to depend onthe local utility grid to draw power in the night Ø Inefficiency: Since not all the light from the sunis absorbed by the solar panels therefore most solar panels have a %40efficiency rate which means %60 of the sunlight gets wasted and is notharnessed.Ø Installation: For home users, asolar energy installation may not require huge space but for big companies, alarge area is required for the system to be efficient in providing a source ofelectricity. Uses of Solar Energy: -§ Heaters Green houses§ Cars Water pumps§ Light Desalination§ Satellite chilling§ Dryers Solar ponds§ Calculators ThermalCommercial use§ On an officebuilding, roof areas can be covered with solar panels§ Remote buildingsuch as school, communities can make use of solar energy.§ In developingcountries, this solar panels are very much useful.
§ Even on the highways,for every five Kilometers, solar telephones are used?????? ?? ???? Betterways of usage:v Governmentshould take measures and see that solar light are used as street light in all theareas.v Wecan place solar panels in the useless lands instead of keeping these solar itaway uselessly. v Wecan also keep these solar panels in the deserts, where we can make use of thisenergy with the help of a rechargeable battery,v Efficiencyof solar panels depends on the range of frequencies of light that strikes thesurface. So they can give higher efficiency if we spilt the light intodifferent frequency ranges and direct the beams on to the cells tuned to thesefrequencies.v Buildinga new home is the best time to design and orient the home the to take theadvantage of the sun’s rays.
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