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1、吉林工程技术师范学院信 息 工 程 学 院学 士 学 位 论 文中英文资料学生姓名： 张建木专 业： 电子信息工程班 级： D0745学 号： 11号论文起止日期：2011年4月至6月英文原文：PHOTOVOLTAIC POWER GENERATIONABSTRACTThis report is an overview of photovoltaic power generation. The purpose of the report is to provide the reader with a general understanding of photovoltaic power gen
2、eration and how PV technology can be practically applied.There is a brief discussion of early research and a description of how photovoltaic cells convert sunlight to electricity. The report covers concentrating collectors, flat-plate collectors, thin-film technology, and building-integrated systems
3、. The discussion of photovoltaic cell types includes single-crystal, poly-crystalline, and thin-film materials. The report covers progress in improving cell efficiencies, reducing manufacturing cost, and finding economic applications of photovoltaic technology. Lists of major manufacturers and organ
4、izations are included, along with a discussion of market trends and projections.The conclusion is that photovoltaic power generation is still more costly than conventional systems in general. However, large variations in cost of conventional electrical power, and other factors, such as cost of distr
5、ibution, create situations in which the use of PV power is economically sound. PV power is used in remote applications such as communications, homes and villages in developing countries, water pumping, camping, and boating. Grid-connected applications such as electric utility generating facilities a
6、nd residential rooftop installations make up a smaller but more rapidly expanding segment of PV use. Furthermore, as technological advances narrow the cost gap, more applications are becoming economically feasible at an accelerating rate.INTRODUCTIONThis report is the result of Gale Greenleafs Octob
7、er 19, 1998 request for proposal. Bill Louk and Tom Penick responded to her request with a proposal, dated October 30, 1998, to continue earlier research on photovoltaic power generation. The proposal was approved and resulted in continued research followed by a presentation on November 30, 1998 and
8、 this final report on photovoltaic power generation.PHOTOVOLTAIC TECHNOLOGYScientists have known of the photovoltaic effect for more than 150 years. Photovoltaic power generation was not considered practical until the arrival of the space program. Early satellites needed a source of electrical power
9、 and any solution was expensive. The development of solar cells for this purpose led to their eventual use in other applications.DISCOVERY AND DEVELOPMENT OF PHOTOVOLTAIC POWERThe photovoltaic effect has been known since 1839, but cell efficiencies remained around 1% until the 1950s when U. S. resea
10、rchers were essentially given a blank check to develop a means of generating electricity onboard space vehicles. Bell Laboratories quickly achieved 11% efficiency, and in 1958, the Vanguard satellite employed the first practical photovoltaic generator producing a modest one watt. In the 1960s, the s
11、pace program continued to demand improved photovoltaic power generation technology. Scientists needed to get as much electrical power as possible from photovoltaic collectors, and cost was of secondary importance . Without this tremendous development effort, photovoltaic power would be of little use
12、 today.POWER OUTPUT AND EFFICIENCY RATINGSThe figures given for power output and efficiency of photovoltaic cells, modules, and systems can be misleading. It is important to understand what these figures mean and how they relate to the power available from installed photovoltaic generating systems.P
13、ower RatingsPhotovoltaic power generation systems are rated in peak kilowatts (kWp). This is the amount of electrical power that a new, clean system is expected to deliver when the sun is directly overhead on a clear day. We can safely assume that the actual output will never quite reach this value.
14、 System output will be compromised by the angle of the sun, atmospheric conditions, dust on the collectors, and deterioration of the components. When comparing photovoltaic systems to conventional power generation systems, one should bear in mind that the PV systems are only productive during the da
15、ytime. Therefore, a 100 kW photovoltaic system can produce only a fraction of the daily output of a conventional 100 kW generator.Efficiency RatingsThe efficiency of a photovoltaic system is the percentage of sunlight energy converted to electrical energy. The efficiency figures most often reported
16、are laboratory results using small cells. A small cell has a lower internal resistance and will yield a higher efficiency than the larger cells used in practical applications. Additionally, photovoltaic modules are made up of numerous cells connected in series to deliver a usable voltage. Due to the internal resistance of each cell, the total resistance increases and the efficiency drops to about 70% of
