Term paper on Solar Energy
Solar Energy Essays
While the free essays can give you inspiration for writing, they cannot be used 'as is' because they will not meet your assignment's requirements. If you are in a time crunch, then you need a custom written term paper on your subject (solar energy)
Here you can hire an independent writer/researcher to custom write you an authentic essay to your specifications that will pass any plagiarism test (e.g. Turnitin). Waste no more time!
Presentation DialogueSOLAR ENERGY. All life on Earth depends on energy from the sun. Solarenergy is the source of energy for photosynthesis. It provides the warmthnecessary for plants and animals to survive. The heat from the sun causeswater on the Earth's surface to evaporate and form clouds that eventuallyprovide fresh rainwater. Solar energy is the result of thermonuclear fusion reactions deepwithin the sun. These reactions produce so much energy that they keep thesurface temperature of the sun at about 10,300B0F (5,700B0C). Even though solarenergy is the largest source of energy received by the Earth, its intensityat the Earth's surface is actually very low due to the large distance betweenthe Earth and the sun and the fact that the Earth's atmosphere absorbs andscatters some of the radiation. Even on a clear day with the sun directlyoverhead, the energy that reaches the Earth's surface is reduced about 30percent by the atmosphere. When the sun is near the horizon and the sky isovercast, the solar energy at ground level can be negligible. It also variesfrom one point to another on the Earth's surface. Nevertheless, in the 20th century, the sun's energy has become anincreasingly attractive source for small amounts of direct power to meethuman needs. A number of devices for collecting solar energy and convertingit into electricity have been developed, and solar energy is used in avariety of ways. Solar energy is used to heat houses, and in many countriesspecially designed solar ovens are used for cooking. The sun also suppliesenergy to electric generators that provide power for weather andcommunications satellites and for radio and television equipment.Because the intensity of the sun's radiation at the surface of theEarth is so low, collectors designed to capture solar energy must be large.In the sunniest parts of the continental United States, for example, in orderfor a collector to gather enough energy to serve one person for one day, thearea of the collector's surface must be about 430 square feet (40 squaremeters). The actual energy that can be used depends on the efficiency of thecollector and of the device that converts the radiation into usable energy. Flat-plate collectors. The most common flat-plate collectors consistof a dark metal plate, covered with one or two sheets of glass, that absorbsheat. The heat is transferred to air or water, called carrier fluids, thatflows past the back of the plate. This heat may be used directly or it may betransferred to another medium. Flat-plate collectors are used for home andhot-water heating . Flat-plate collectors typically heat carrier fluids totemperatures ranging from 150B0 to 200B0F (66B0 to 93B0C). The efficiency of suchcollectors varies from 20 to 80 percent.Concentrating collectors. When higher temperatures are required, aconcentrating collector is used. These collectors reflect and concentratesunlight from a wide area. One such device, called a solar furnace, wasinstalled in the Pyrenees in France and has several acres of mirrors focusedon a single target. The energy concentrated at the target is 3,000 times thatreceived by any single mirror, and the unit produces temperatures of up to3,630B0F (2,000B0C). Another structure, the so-called "power tower" plant nearBarstow, Calif., generates 10,000 kilowatts of electricity. Here, the furnaceacts as a boiler and generates steam for a steam turbine-electric generatorpower plant. In sophisticated concentrating collectors such as the Californiatower, each mirror is rotated by a heliostat that directs the sun's rays fromthe mirror to the target. Positioning motors, drives, and controllers makesuch systems expensive. Less costly collectors can produce temperatures lowerthan those of more advanced concentrating collectors but higher than those offlat-plate collectors. For example, parabolic reflectors that concentratesunlight on black pipes can produce fluid temperatures of about 400B0 to 550B0F(200B0 to 290B0C) and can concentrate the solar energy up to 50 times itsoriginal strength.Small Stand-Alone DC SystemThe small stand-alone system is an excellent replacement for propaneor kerosene lights in a remote cabin, a recreational vehicle or a boat. Thesize of the photovoltaic (PV) array and battery will depend upon individualrequirements. The actual sizing methods are discussed elsewhere. The PV arraycharges the battery during daylight hours and the battery supplies power tothe loads as needed. The charge regulator terminates the charging when thebattery reaches full charge. The load center may contain meters to monitorsystem operation and fuses to protect wiring in the event of malfunction orshort circuit in the house.PV - Generator CombinationThe PV - Generator Combination system may be an economicalalternative to a large stand-alone PV system, because the PV array does nothave to be sized large enough for worst case weather conditions. A gasoline,propane or diesel generator combined with a battery charger can supply powerwhen the PV array falls short. If the PV array is sized for averageconditions, then during extended overcast situations or periods of increasedload, the generator can be started. When batteries are low, the generatorwill power the AC loads in the house as well as a battery charger to helprecharge the batteries. If the PV array is sized much smaller than needed fornormal use, the generator can power peak loads such as doing laundry orpumping water and simultaneously run the battery charger to charge thebattery bank. In addition to allowing for a smaller PV array, a back-upcharging system may also allow use of a smaller battery bank. Generator andbattery bank size must be chosen carefully for reliable system operation. Seethe system sizing section for more details on equipment choice.Utility IntertieThe utility intertie system is also used in a grid connected house.Instead of storing power in batteries, it is sold to the utility company. TheUtility Intertie System employs a special type of inverter, which inverts DCpower from the PV array into low distortion AC, acceptable for purchase bythe local utility power company. Batteries are not required for storage. Thepower is delivered through a kilowatt-hour (kWh) meter to the utility grid asit is produced by the PV modules. A second kWh meter is used to measure thepower consumed by the loads in the house. The user of this system will noticeno difference from any utility system, except lower utility bills or possiblypayments from the power company for excess electricity that is generated.AC Photovoltaic Module IntertieAt last ordinary home owners can begin to reduce their dependence onutility power for their electricity. This type of utility sellback system iscomprised of PV modules with small inverters mounted on them. This allows theoutput of the inverter-module combinations to be connected directly to the ACline. The utility may require a second meter and disconnect. The installationcost of this type of intertie system is much lower than that of a largeinverter system. A small system can be installed, and as finances allow,additional AC PV modules can easily be added to the system.ConservationConservation plays an important role in keeping the cost of aphotovoltaic system down. The use of energy efficient appliances and lightingas well as non-electric alternatives wherever possible can make solarelectricity a cost competitive alternative to gasoline generators and in some
cases, utility power.Cooking, Heating & CoolingConventional electric cooking, space heating and water heatingequipment use a prohibitive amount of electricity. Electric ranges...
MLA Style
. EssayMania.com. Retrieved on 11 Feb, 2012 from
<http://essaymania.com/101075/solar-energy>
More College Papers
Dieting Dilemmas
The dilemma of shedding a few pounds faces women in the world everyday. We are overwhelmed with diets and medications, all guaranteeing they are a sure-fire way to lose weight and lose it fast. The New York Times on the Web Forums has a forum entitled Women's health. The topic of this forum is th
Depression And Its Treatment
Depression and its Treatment Depression is a common disorder and will probably affect someone you know in your lifetime. Major depression affects at least 10% of the population at some stage in their lifetime, and even larger percentages suffer from mild or moderate depression. According to John
1500S
1500s After 1500 there were many signs that a new age of world history was beginning, for example the discovery of America and the first European enterprises in Asia. This |new ageX was dominated by the astonishing success of one civilization among many, that of Europe. There was more and more conti