Solar array

J. Y. P. Mui, Low Cost Solar Array Project, NASA/JPL Contract 954334, Union Carbide Corp., June 1979. 

Solar array efficiency depends on its orientation to the sun. The best result is achieved if the array faces the sun at an angle of 90° to S5°. Precise orientation can be achieved either through the rotation of the whole spacecraft, or the rotation of the solar arrays only. To ensure constant electricity flow regardless of changes in spacecraft orientation, solar arrays charge... 

Solar Arrays Visual solar -Long life-span -Require precision Sun The most widely used... 

Unlike radioisotope generators, nuclear reactors utilize the much more intense process of nuclear chain reaction. Since this process is controlled in the reactor, the energy output could be regulated depending on the system s requirements. It actually could produce twice its nominal power, if necessai"y. Nuclear reactors can pro dde greater electrical output than radioisotope generators using the same types of thermal converters. This output is comparable to that of fuel cells and solar arrays, while nuclear reactors are more durable and compact. 

TVivedi, R. Somboonsuk, K., in Proc. Flat-Plate Solar Array Research Forum on the High Speed Growth and Characterization of Crystals for Solar Cells K. Dumas EM., JPL-Publication 84-23, 1984. 

Hoffman, D. J. Kerslake, T. W. Hepp, A. F. Jacobs, M. K. Ponnusamy, D. 2000. Thin-film photovoltaic solar array parametric assessment. Proceedings of the 35th Intersociety Energy Conversion Engineering Conference (IECEC 35). IEEE, Piscataway, NJ. pp. 670-680. 

Vest, G. 1983. Metallization with generic metallo-organic inks. JPL Proceedings of the Flate-Plate Solar Array Research Forum on Photovoltaic Metallization Systems (NASA Center for AeroSpace Information Pasadena, CA). (Document ID. 19831115). 

This project adds to NYC Transit s use of clean energy power sources. In 1996 NYPA installed a 300-kW roof-mounted solar power array at the Gun Hill bus depot in the Bronx. During warm weather months, the solar array supplies 15 percent of this bus depots electrical needs. NYC Transit has been using solar energy to provide power to the Maspeth Warehouse Facility in Queens and the Jackie Gleason Bus Depot in Brooklyn since the late 1990s. 

Some designs use solar arrays that are several kilometers long on each side. The largest solar panels in space are being used on the International... 

A potentially useful concept to contrast SPS with is the constructing a ground-based solar power system that generates an equivalent amount of power. Such a system would require a large solar array built in a well-... 

The use of microwave beams to heat the oceans has also been studied. Some research suggests that microwave beams would be capable of deflecting the course of hurricanes. NASDA (Japan s national space agency) has been researching this area and plans to launch an experimental satellite of 10-kW to 1-MW. Japan plans to assemble a space-based solar array by 2040. 

Kharkats YI, German ED, Kazarinov VE, Pshenichnikov AG, Pleskov YV.(1985) Hydrogen production by solar energy Optimization of the plant solar array + electrolyzer . IntJ hydrogen Energy 10 617-621... 

Another solar firm, SolFocus (www.solfocus.coml has developed solar arrays that use just one-thousandth as much semiconductor material as standard solar panels. The arrays are set with curved mirrors that focus sunlight onto solar cells measuring one-square centimeter, which concentrates the light 500 times. These cells efficiency is greater than 38%, compared to the 13% to 19% efficiency for silicon photovoltaic cells. SolFocus projects that costs per kilowatt-hour will fall from 24 to 28 cents in 2008 to 13 to 14 cents by 2010. 

In May 2006, the University of Neuchatel in Switzerland announced a technique using a film created for use in space that yields power densities of 3,200 watts per kilogram. There is also interest in SSP in Japan, where the JAXA space agency has hopes to launch a satellite that will spread into a sizable solar array capable of beaming 100-kilowatts of microwave or laser power to Earth. 

Figure 2.3. A schematic of the Chandra Observatory showing the typical components including the solar arrays, aspect cameras, mirror assembly, instrument module, and optical bench. The Chandra Observatory weighs 4800 kg and orbits the Earth every 64 hours in a 10,000 by 140,000 km orbit that extends 1/3 of the distance the moon. Including the solar panels, the observatory s dimensions are 14m by 20m.

In poly crystalline semiconductor samples, the excited-state lifetime of electron-hole pairs is so short that photocurrent collection is efficient only for carriers created within the space charge (depletion) region. Thin-film processes offer an inexpensive way to prepare large solar arrays, but the semiconductors formed by such processes are almost inevitably polycrystalline. It is not wise to use semiconductor films thicker than the depletion width in such devices because the additional thickness contributes only extra grain barrier boundaries for the majority of carriers to surmount on their way to the back contact. The additional thickness does not provide any additional photocurrent. 

Fig. 15.12. Daily variation in electrolytic hydrogen production rate (1), the solar array temperature (2), and radiation power density (3). Single crystalline silicon solar cells, SPE electrolyzer location, Cape Canaveral, Florida. The time scale denotes minutes elapsed from 5 a.m. (Reprinted from Yu. I. Khar-kats, Electrochemical Storage of Solar Energy, in Environmental Oriented Electrochemistry, C. A. C. Sequeira, ed., Fig. 5, p. 477, copyright 1994. Reproduced with kind permission of Elsevier Science-NL, Sara Burgerhartstraat 25,1055 KV Amsterdam, The Netherlands.)...

The ability of an adhesive to withstand long periods of exposure to a vacuum is of primary importance for materials used in space travel or in the fabrication of equipment that requires a vacuum for operation. The outgassed constituents can also become a source of contamination and be highly objectionable in certain applications, such as with electronic products, optical equipment, and solar arrays. 

A survey of European Space Tribology Laboratory vacuum testing on satellite slip-rings reported that slip-rings designed for satellite solar-array mechanisms had operated satisfactorily over long periods with a variety of Ag/Cu/MoSj compacts . The relationship between brush wear rate and molybdenum disulphide content is shown in Figure 12.5 for some hot-pressed composites in silver with 1% of copper. 

The final unit segment of Mir was the Priroda module, placed in orbit in 1996— ten years after the core module, and five years beyond the planned lifetime of the station. The 42-ft long, 14-ft wide module incorporated optical systems to study the Earth resources. Lacking solar arrays, however, Priroda was unable to generate its own power, relying instead on batteries or on the Mir power network. 

A. Briglio, K. Dumas, M. Leipold, A. Morrison, Flat Plate Solar Array Project Volume III Silicon Sheets and Ribbons, DOE/JPL 1012-125 (1986)... 

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