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Showing papers on "Solar energy published in 1989"


Journal ArticleDOI
TL;DR: In this paper, a new silicon solar cell structure, the passivated emitter and rear cell, is described, which yields independently confirmed efficiencies of up to 22.8%, the highest ever reported for a silicon cell.
Abstract: A new silicon solar cell structure, the passivated emitter and rear cell, is described. The cell structure has yielded independently confirmed efficiencies of up to 22.8%, the highest ever reported for a silicon cell.

689 citations


Book
01 Jan 1989
TL;DR: In this article, a handbook to predict the degradation of solar cell electrical performance in any given space radiation environment is presented, where the interaction of energetic charged particles radiation with solar cells is discussed and the concept of 1 MeV equivalent electron fluence is introduced.
Abstract: The handbook to predict the degradation of solar cell electrical performance in any given space radiation environment is presented. Solar cell theory, cell manufacturing and how they are modeled mathematically are described. The interaction of energetic charged particles radiation with solar cells is discussed and the concept of 1 MeV equivalent electron fluence is introduced. The space radiation environment is described and methods of calculating equivalent fluences for the space environment are developed. A computer program was written to perform the equivalent fluence calculations and a FORTRAN listing of the program is included. Data detailing the degradation of solar cell electrical parameters as a function of 1 MeV electron fluence are presented.

230 citations


Patent
13 Mar 1989
TL;DR: In this article, a supported photovoltaic array and method in which support elements are in rows spaced from one another and are bi-directionally spanned by members which mount PV modules that are separated from each other and are secured to the spanning members by cushioned load-spreading attachments positioned in the spaces between adjacent modules.
Abstract: A supported photovoltaic array and method in which support elements are in rows spaced from one another and are bi-directionally spanned by members which mount photovoltaic modules that are separated from one another and are secured to the spanning members by cushioned load-spreading attachments positioned in the spaces between adjacent modules.

186 citations


Journal ArticleDOI
TL;DR: In this paper, the authors show that by using low collector flow rates and taking measures to ensure the water in the storage tank remains stratified, the energy delivered by a forced-flow solar system can be increased substantially.

185 citations


Journal ArticleDOI
TL;DR: In this article, an amorphous silicon alloy based solar cell with a novel structure in which the optical gap of the intrinsic layer changes in a substantial portion of the bulk was developed.
Abstract: We have developed an amorphous silicon alloy based solar cell with a novel structure in which the optical gap of the intrinsic layer changes in a substantial portion of the bulk. Computer simulation studies show that for a given short circuit current, it is possible with this structure to obtain higher open circuit voltage and fill factor than in a conventional cell design. Experimental cell structures have been made and confirm the theoretical prediction. The new cell design shows a considerable improvement in efficiency. Incorporation of this structure in the bottom cell of a triple device has resulted in the achievement of 13.7% efficiency under global AM1.5 illumination.

160 citations


Patent
12 Dec 1989
TL;DR: In this article, a survivable solar power-generating system for use with spacecraft is disclosed comprising optical means positioned to collect and concentrate solar energy flux, a flexible solar energy transmission line for conducting the concentrated solar flux towards a solar energy converter, and solar energy conversion means including an array photovoltaic cells for converting the solar energy to electrical power to be applied to on-board equipment of the spacecraft.
Abstract: A survivable solar power-generating system for use with spacecraft is disclosed comprising optical means positioned to collect and concentrate solar energy flux, a flexible solar energy flux transmission line for conducting the concentrated solar flux towards a solar energy converter, and solar energy conversion means including an array photovoltaic cells for converting the solar energy flux to electrical power to be applied to on-board equipment of the spacecraft. A protected enclosure is positioned about the photovoltaic cells to shield them from destructive radiation and particulate matter. The transmission line includes a plurality of optical fiber waveguides whose input ends are positioned to receive the concentrated solar energy flux. Means are provided for moving the input ends of the optical fiber waveguides to optimize the quantity of concentrated solar flux entering the waveguides.

156 citations


Patent
14 Apr 1989
TL;DR: In this article, a novel solar tracking mechanism incorporating a number of practical features that give it superior environmental resilience and exceptional tracking accuracy is presented. But the system's primary intended application would be to focus highly concentrated sunlight into optical fibers for transmission to core building illumination zones, and the system may also have potential for photovoltaic or photothermal solar energy conversion.
Abstract: This invention is a novel solar tracking mechanism incorporating a number of practical features that give it superior environmental resilience and exceptional tracking accuracy. The mechanism comprises a lightweight space-frame assembly supporting an array of point-focus Fresnel lenses in a two-axis tracking structure. The system is enclosed under a glass cover which isolates it from environmental exposure and enhances tracking accuracy by eliminating wind loading. Tracking accuracy is also enhanced by the system's broad-based tracking support. The system's primary intended application would be to focus highly concentrated sunlight into optical fibers for transmission to core building illumination zones, and the system may also have potential for photovoltaic or photothermal solar energy conversion.

119 citations


Book
15 Jan 1989
TL;DR: In this article, the assessment and appreciation for drinking-water disinfection is discussed. And the authors present a technical report entitled: solar ultraviolet radiation assessment and assessment for drinking water disinflection.
Abstract: Edited version of the project technical report entitled: Solar ultravioletradiation : assessment and appreciation for drinking-water disinfiection

107 citations


01 Jan 1989
TL;DR: In this article, the important achievements and latest advancements of photochemical energy conversion are summarized, including basic principles of energy and electron transfer, charge separation, energy conversion in homogeneous and heterogeneous systems, photocatalysis, photoelectrochemisty, photochemistry in organized assemblies, biomimetic photochemistry, photosynthesis, and new strategies to the production of fuels and useful chemical through environmentally clean renewable sources are examined.
Abstract: This book presents proceedings in which the important achievements and latest advancements of photochemical energy conversion are summarized. Various aspects of photochemical solar energy, including the basic principles of energy and electron transfer, charge separation, energy conversion in homogeneous and heterogeneous systems, photocatalysis, photoelectrochemisty, photochemistry in organized assemblies, biomimetic photochemistry, photosynthesis, and new strategies to the production of fuels and useful chemical through environmentally clean renewable sources are examined.

83 citations


Journal ArticleDOI
TL;DR: In this article, a laser texturing technique on the top surface of a laser grooved, buried top contact polycrystalline silicon solar cell has been employed, which has demonstrated an independently confirmed 16.7% (air mass 1.5, 25°C) efficiency.
Abstract: In the evolution of single‐crystal silicon solar cells, crystallographic texturing of the cell surface using anisotropic etches was an important step in improving cell performance. Unfortunately, this technique is ineffective for polycrystalline silicon solar cells due to generally unfavorable grain orientation. This limitation has been overcome by employing a new laser texturing technique on the top surface of a laser grooved, buried top contact polycrystalline silicon solar cell. This approach has demonstrated an independently confirmed 16.7% (air mass 1.5, 25 °C) efficiency for a 10.5 cm2 polycrystalline silicon solar cell, the highest efficiency ever reported for a polycrystalline cell of this size.

78 citations


Journal ArticleDOI
TL;DR: In this article, the reaction CH4 + CO2 = 2CO + 2H2 was studied as a thermochemical pipe for storage and transport of solar energy in a 20 kW solar furnace at the Weizmann Institute of Science.

Journal ArticleDOI
TL;DR: In this article, a triple stack amorphous silicon solar cell with an n−i−p−n−i•p n−p•n−p n•i−i·p n·i•P n−n•i·P structure was used to split the water into hydrogen and oxygen.
Abstract: A new direct one step method to split the water into hydrogen and oxygen by using a triple stack amorphous silicon solar cell with an n‐i‐p‐n‐i‐p‐n‐i‐p structure is reported. The ruthenium oxide layer, which is directly painted on the back surface of the solar cell, catalytically aids the evolution of the oxygen. The isolated islands of platinum deposited on the top side of the cell materially help the production of hydrogen. The conversion efficiency of 5% of solar to chemical energy in steady state is achieved under simulated AM1, 100 mW/cm2 solar radiation.

Journal ArticleDOI
TL;DR: In this paper, an analytical model of the adsorption solar cooling cycle is presented, which accounts for heat and mass transfers in a porous bed in a two-dimensional transient process.

Journal ArticleDOI
01 May 1989-Nature
TL;DR: In this article, a non-imaging light-gathering device was used to concentrate terrestrial sunlight by a factor of 56,000, producing an irradiance that could exceed that of the solar surface.
Abstract: THEflux at the surface of the Sun, ∼6.3 kW cm-2, falls off with the square of distance to a value of ∼137 mW cm-2 above the Earth's atmosphere, or typically 80–100 mW cm-2 at the ground. In principle, the second law of thermodynamics permits an optical device to concentrate the solar flux to obtain temperatures at the Earth's surface not exceeding the Sun's surface temperature. In practice, conventional means for flux concentration fall short of this maximum because imaging optical designs are inefficient at delivering maximum concentration. Non-imaging light-gathering devices can improve on focusing designs by a factor of four or more, and approach the thermodynamic limit. We have used a non-imaging design to concentrate terrestrial sunlight by a factor of 56,000, producing an irradiance that could exceed that of the solar surface. This opens up a variety of new applications for making use of solar energy.

Journal ArticleDOI
TL;DR: In this article, a two-terminal, monolithic two-junction cascade solar cell consisting of an Al0.37Ga0.63As (Eg=1.93 eV) upper cell and a GaAs lower cell was constructed using a metal-interconnect contact fabricated during postgrowth processing.
Abstract: A 27.6% efficiency measured under 1 sun, air mass 1.5 illumination has been achieved in a two‐terminal, monolithic two‐junction cascade solar cell consisting of an Al0.37Ga0.63As (Eg=1.93 eV) upper cell and a GaAs lower cell. The component cells were electrically connected together using a metal‐interconnect contact fabricated during post‐growth processing. Also, a prismatic cover glass was bonded to the front surface of the cascade structure to minimize the obscuration effect introduced by the grid lines and metal‐interconnect contacts. As the cascade cell was operated under air mass 0 illumination, an efficiency of 23.0% was obtained. Both results represent the highest 1 sun efficiencies ever reported. The implications of achieving this high efficiency in a two‐junction cascade solar cell for terrestrial and space applications are also described.

Patent
11 Aug 1989
TL;DR: A solar concentrator device has a solar energy receiver and a solar reflector including a plurality of individual panels turnable about two mutually perpendicular axes as discussed by the authors, such that the panels in one row are jointly turnable on a first axis, the same row are turnable also relative to two further axes.
Abstract: A solar concentrator device has a solar energy receiver and a solar energy reflector including a plurality of individual panels turnable about two mutually perpendicular axes so that the panels in one row are jointly turnable about a first axis, the panels in the same row are turnable also relative to two further axes

Journal ArticleDOI
TL;DR: In this paper, the effect of nonuniform dislocation distribution on recombination properties of GaAs thin films on Si substrates was investigated and numerical analysis showed that majority carrier trapping must be considered.
Abstract: This paper describes some recent developments in GaAs thin‐film solar cells fabricated on Si substrates by metalorganic chemical vapor deposition and numerically analyzes them.GaAs solar cells with efficiency of more than 18% are successfully fabricated on Si substrates by reducing the dislocation density. Photovoltaic properties of GaAs/Si cells are analyzed by considering the effect of nonuniform dislocation distribution on recombination properties of GaAs thin films on Si substrates. Numerical analysis shows that the effect of majority‐carrier trapping must be considered. High efficiency GaAs solar cells with total‐area efficiency of over 20% on Si substrates can be realized if dislocation density can be reduced to less than 5×105 cm−2.

01 Aug 1989
TL;DR: In this paper, a procedure and solar radiation related data from which the diurnally, hourly and daily variation of the global, direct beam and diffuse insolation on Mars are calculated.
Abstract: Detailed information on solar radiation characteristics on Mars are necessary for effective design of future planned solar energy systems operating on the surface of Mars. Presented here is a procedure and solar radiation related data from which the diurnally, hourly and daily variation of the global, direct beam and diffuse insolation on Mars are calculated. The radiation data are based on measured optical depth of the Martian atmosphere derived from images taken of the sun with a special diode on the Viking cameras; and computation based on multiple wavelength and multiple scattering of the solar radiation.

Journal ArticleDOI
TL;DR: In this article, the authors describe the results to date of a cooperative project among the Solar Energy Research Institute (SERI), the Electric Power Research Institute, the Florida Solar Energy Center (FSEC), and the Pacific Gas and Electric Company (PG&E) to build a spectral solar radiation data base.

Patent
07 Sep 1989
TL;DR: In this article, an active "attic solar energy vehicle" is proposed to heat swimming pools, spas, hot tubs, domestic hot water and in providing space heating/cooling and in cooling overheated swimming pools or other bodies of water.
Abstract: The "unmodified" roof (32) and "unmodified" attic (34), of a residential or similar building, are used in conjunction with an "attic based" air to liquid forced air heat exchanger (46) to form an active "attic solar energy vehicle". This solar (30) based system is used to heat swimming pools, spas, hot tubs, domestic hot water and in providing space heating/cooling and in cooling overheated swimming pools or other bodies of water--in a cost efficient way. Low operating cost forced air convection principles that make use of the temperature differentials present are applied. The "unmodified" roof (32) functions as a massive solar (30) collector. The "unmodified" attic (34) functions as a heat transfer and storage medium. The forced air to liquid heat exchanger (46) takes hot attic (34) air directly off of the interior of the roof structure (32) and transfers it to water or other liquid. When used for swimming pool (76) heating, the "attic solar energy vehicle" can save 90% of the fossil fuel normally required to heat swimming pools (76). In addition, an active solar energy system is presented without the corresponding problems associated with roof (32) mounted solar panel systems.

Patent
04 Aug 1989
TL;DR: In this paper, individual solar cells are connected directly to the interconnect circuit by contact fingers that are an integral part of the inter-connect circuit and can be accomplished by manual or automated process.
Abstract: Individual solar cells are electrically interconnected through an interconnect circuit supported on a flexible dielectric substrate. The solar cells are connected directly to the interconnect circuit by contact fingers that are an integral part of the interconnect circuit. The interconnection of the individual solar cells can be accomplished by manual or automated process.

Proceedings ArticleDOI
15 Oct 1989
TL;DR: In this paper, a novel interface circuit between solar cells and a commercial AC bus using Van Allen's multivibrator is presented, where the AC source is used for the backup of solar cells, and the source and load power flow is automatically balanced by the circuit itself without any external phase control.
Abstract: A novel interface circuit between solar cells and a commercial AC bus using Van Allen's multivibrator is presented. In this circuit, the AC source is used for the backup of solar cells, and the source and load power flow is automatically balanced by the circuit itself without any external phase control. Based on an analysis of the characteristics of the oscillator, the authors describe a novel method to control the DC power from the solar cells according to the current load conditions as well as a simple and fast optimization method to derive the maximum solar power. >

Journal ArticleDOI
TL;DR: The 10 MWe Solar Thermal Central Receiver Pilot Plant near Barstow, Calif., completed a three-year period of power production testing in July 1987 as discussed by the authors. During this period the plant's capacity factor, system efficiency, and availability were studied to assess the operational capability of Solar One to reliably supply electrical power.
Abstract: Solar One, the 10 MWe Solar Thermal Central Receiver Pilot Plant near Barstow, Calif., completed a three-year period of power production testing in July 1987. During this period the plant's capacity factor, system efficiency, and availability were studied to assess the operational capability of Solar One to reliably supply electrical power. The long-term performance of keyplant components, such as the heliostats and the receiver, was also studied. During the three years of power production operation, Solar One achieved increases in capacity factor, system efficiency, and availability. Heliostat operation was reliable, and only small amounts of mirror corrosion were observed.

Patent
23 Mar 1989
TL;DR: In this paper, a solar energy collector is described for selectively collecting an electrical energy and a thermal energy at the same time from solar energy, using an inorganic and metal composite in the form of a roof tile or a wall-forming member.
Abstract: A solar energy collector device is disclosed for selectively collecting an electrical energy and a thermal energy at the same time from a solar energy The device comprises an inorganic-and-metal composite in the form of a roof tile or a wall-forming member which includes a solar battery exposed to sun rays and a heat medium passageway disposed underneath the battery The density of distribution of a particulate inorganic substance within a metal mass is varied through the areas of the tile or wall member so as to effectively collect the respective energies without adversely affecting the interior conditions of a building in which the device is installed

Journal ArticleDOI
TL;DR: In this article, the authors described the methods used to derive the wavelength-dependent measurement uncertainty for each spectral scan (i.e., spectra) and presented summaries of the magnitudes for each.

Journal Article
TL;DR: In this article, a new approach, Central Solar Heating Plant with Seasonal Storage (CSHPSS), which allows for efficient solar collection throughout the year, is discussed, where a thermal storage facility can be charged so that a sufficient heat source is prepared to meet nearly 100% of the winter space heating and annual hot water loads.
Abstract: Every year, the United States uses approximately 15 quads of energy (26 quads of primary fuels) to heat buildings and water for domestic use. Applying solar energy to these loads is attractive because of the low-temperature requirements of the end-uses. However, past solar approaches to space heating in cold winter climates have not fared well technically or economically because the winter resource in northern climates is not adequate and is highly intermittent. This paper discusses a new approach, Central Solar Heating Plant with Seasonal Storage (CSHPSS), which allows for efficient solar collection throughout the year. With CSHPSS, a thermal storage facility can be charged so that a sufficient heat source is prepared to meet nearly 100% of the winter space heating and annual hot water loads. Recent developments in northern Europe have shown that, when implemented on a large scale, CSHPSS is very efficient and can provide cost competitive and reliable energy. In the United States, the first CSHPSS project is in a final engineering phase.

Book
15 Dec 1989
TL;DR: In this paper, photoelectrochemical solar energy conversion and its storage is discussed and an overview of current processes and potential technical applications for students, researchers, and engineers are provided.
Abstract: Conversion of solar energy is an important contemporary research field with the objective of substituting fossil and nuclear power sources. This text summarizes and critically discusses photoelectrochemical solar energy conversion and its storage. After an introduction to the fundamental physics of the semiconductor/electrolyte interface, technical cells for water electrolysis for the generation of fuel-hydrogen and the electrochemical conversion of other energy rich chemicals are explained. The application of new electrochemical, such as microheterogeneous, semiconductors, liquid-junction solar cells and electrode coatings, are discussed. The book provides an overview of current processes and potential technical applications for students, researchers, and engineers.

Journal ArticleDOI
TL;DR: In this paper, two new types of large-area (>8.5 cm2), backside, point-contact solar cells with doped surfaces, designed for use in unconcentrated sunlight, were reported.
Abstract: This letter reports two new types of large‐area (>8.5 cm2), backside, point‐contact solar cells with doped surfaces, designed for use in unconcentrated sunlight. One type was fabricated on an intrinsic substrate with an optimized phosphorus diffusion on the sunward surface. The apertured‐area efficiency was independently measured to be 22.3% at 1 sun (0.100 W/cm2), 25 °C, the highest reported for a silicon solar cell. The other type is constructed on a doped substrate, and has an apertured‐area efficiency of 20.9%, the highest reported for a point‐contact solar cell with a base in low‐level injection. Both cells have record open‐circuit voltages above 700 mV.

Patent
03 Apr 1989
TL;DR: A low cost easily assembled solar energy panel employing as its major component, a double skinned sheet of polycarbonate which has a plurality of uniformly spaced, rib members separating the two skins.
Abstract: A low cost easily assembled solar energy panel employing as its major component, a double skinned sheet of polycarbonate which has a plurality of preferably uniformly spaced, rib members separating the two skins. The panel may employ a fluid input and fluid output at the same end of the panel or at opposite ends thereof.

Journal ArticleDOI
TL;DR: In this paper, the cumulative probability distribution of instantaneous terrestrial insolation values is used to construct the instantaneous utilizability curve, which gives a conservative estimate of long-term performance.