Showing papers on "Photovoltaic thermal hybrid solar collector published in 1982"

On the Coexistence of Solar-Energy Conversion and Plant Cultivation

Abstract: In this paper we propose a configuration of a solar, e.g., photovoltaic, power plant, which allows for additional agricultural use of the land involved, although the collectors are optimized for solar-energy conversion. If the collectors are not installed directly on the ground, but are elevated by about 2m above the ground with the periodic distance between collector rows of about three times the height of the collectors, one achieves nearly uniform radiation, (integrated over the day), on the ground of a value of about two-thirds of the global radiation without solar collectors. The mathematical relations allowing calculation of the fraction of light reaching the ground under the collector field are derived. Numerical calculations for both the direct and diffuse part of solar radiation are carried out yielding the seasonal and local dependence of this fraction. In addition, we give an outline of the various advantages offered by this configuration.

Luminescent solar concentrators for energy conversion

Abstract: Solar energy is the prominent renewable source of electricity if cheap methods will be designed for its concentration and conversion. The geographical, seasonal and spectral distribution of the terrestrial solar energy are described. The concept of non-tracking fluorescent concentrators and the mathematical background for collection and concentration of direct and diffuse light are discussed. The single plate, multiple stacks and thin films doped by one or more colorants are reviewed. The differences between inorganic and organic materials are analyzed. Suggestions for new hybrid systems are made.

Non-conventional energy sources

Abstract: This book presents the papers given at a conference on renewable energy sources. Topics considered at the conference included energy planning in developing countries, energy demand modeling, climatological aspects, solar mapping, solar thermal conversion, solar water heaters, solar power plants, thermal storage systems, radiative cooling, photovoltaic power supplies, photoelectrochemistry, small wind systems for remote locations, geothermal energy, and the use of solar collectors for grain drying.

Solar energy recovery system

Abstract: A solar tracking system for a sun sensitive system such as a solar energy generating unit is described. Means for tracking the sun in bright sunlight and in cloudy conditions having a sun sensing mode and a blind mode are disclosed. Solar energy generating units compatible with the solar tracking system capable of automatically operating a stock watering system are also disclosed.

An Introduction to Solar Energy for Scientists and Engineers

Abstract: Presents the fundamental principles behind solar energy technology for serious students in science and engineering. Discusses the apparent motion of the sun and the energy it provides at the earth's surface, the principles of heat transfer and optics, solar heating applications, and thermodynamic and photovoltaic conversion of solar energy to useful work. Contains numerical examples and derivations of formulas.

Thermophotovoltaic power source

Abstract: A thermophotovoltaic power source comprising a Cassegrain solar collector and concentrator, a thermal vessel including a containment vessel holding thermal storage material therein, the containment vessel having the shape of an annulus closed at one end and disposed with its open end in registry with an aperture in the thermal vessel, with a selective band radiating layer coating the internal surface of the annulus cavity, and further including an external array of photovoltaic cells mounted on a cooled cylinder disposed for insertion by a positioning motor to a desired depth into the annulus cavity and thus into adjacency with the selective band radiating layer. Concentrated solar energy is applied by the solar collector through a second aperture into the thermal vessel to heat the thermal storage material in the containment vessel and thereby cause the selective radiating layer to radiate energy to excite a current in the photovoltaic array. Constant current control and/or load-matching are obtained by varying the degree of insertion of the photovoltaic array into the thermal storage annular cavity.

Solar energy concentrating slat arrangement and collector

Abstract: Disclosed are improved elongated, reflective slat concentrators and elongated multi-conduit/multi-fluid collectors and systems thereof. The reflective slats are generally of rectangular configuration and extending about a curve. In systems utilizing the concentrators, the collector is located above the concentrator, i.e. forwardly of the concentrator relative to the travel of solar energy to the concentrator.

Analysis of two-phase flow solar collectors with application to heat pumps

Abstract: A thermodynamic model is developed to analyze the thermal performance of twophase solar collectors The well-known equilibrium homogeneous theory is used to model the two-phase flow in the solar collectors The resultant set of coupled ordinary differential equations for saturated pressure and quality of working fluid in the collector tubes are solved by an iterative procedure using a fourth-order RungeKutta method The results are then applied to determine the thermal performance of a solar assisted heat pump which uses two-phase flow collectors as the evaporator The results indicate that even with the use of less expensive bare solar collectors as evaporator for the heat pump, the heating coefficient of performance (COP /SUB H/) as high as 6 can be obtained under realistic ambient conditions provided a proper matching exists between the collector's evaporative capacity and the compressor's pumping capacity

Liquid metal solar power system

Abstract: A solar power system for cogenerating heat and electricity is disclosed. An improved solar collector includes a transparent reflector envelope through which a reflective liquid metal such as mercury is circulated. The liquid metal is preheated as it focuses solar radiation onto the receiver of the collector module. A baffle tube within the receiver is perforated to permit the circulation of working fluid out of the absorption chamber of the receiver into the narrow annulus between the baffle tube and the receiver wall, thereby promoting the rapid generation of vapor. The liquid metal vapor is discharged through the channel of a magnetohydrodynamic generator for producing electrical power in a first power generating stage. The liquid metal vapor is condensed and accumulated in a primary storage reservoir for driving a turbine generator in a second generating stage, thereby providing electrical power during periods of insufficient solar radiation. Liquid metal discharged from the turbine is accumulated in a secondary storage reservoir for supplying the solar collector module during periods of adquate solar radiation.

Solar/microwave vacuum continuous feed distillation apparatus

Abstract: An apparatus for the distillation of a fluid containing at least two constituent components is disclosed. The apparatus includes a microwave energy source and a solar energy collector, both of which may be used to heat a subject fluid to a greater temperature for the purpose of distillation of same. Further, the disclosed invention combines a vacuum within the apparatus to facilitate operation and enhance the overall energy efficiency of the apparatus.

Concentrating/tracking solar energy collector

Abstract: A concentrating/tracking solar energy collector comprised of a rotatable reflective trough assembly having a heat absorber assembly integrally therein. A heat exchange tube supports the absorber assembly in the trough and also serves as an axis point about which the collector rotates.

Solar cell power supply circuit

Abstract: A solar cell power supply circuit for use in a calculator or equipment is disclosed. It includes a solar cell or cells, a back-up capacitor connected to the solar cells, and a circuit element connected to be responsive whether the electromotive force from the solar cells lies within a range of operation for a load element of the solar cells, typically an LSI semiconductor device. The back-up capacitor starts charging when the electromotive force of the solar cells falls out of the range of operation for the load element. Preferably, an alarm sound is delivered when the electromotive force of the solar cells is poor.

Wedge-shaped solar air heating device

Abstract: Wedge-shaped solar air heating device adapted to be mounted exteriorly of a building with its tapered end uppermost and in operative relationship with a window opening or other opening in the wall of the building, said device having two interconnected chambers, one for passage of cool air and the other for heating said cool air by solar radiation.

Bimetallic solar engine

Abstract: The motion produced by a temperature change in a bimetallic element is used as a source of mechanical work energy in a way similar to the way that the bimetallic strip operates in a thermostat but in this thermal engine an array of massive bimetallic strips is repeatedly, alternately heated and cooled by a draft of air which draws first heated air and then cooled air over the bimetallic elements to thereby provide a continuous reciprocating action. In the principal embodiment the required draft is provided by a solar heated convection column which by means of valving draws air first from a solar collector and then from a cooling duct.

Solar Thermal Electricity Generation EURELIOS, the 1 MW(el) Helioelectric Power Plant of the European Communities

Abstract: The different technologies of solar thermal power electricity conversion are discussed and the main power plants under construction or already in operation are listed. EURELIOS, the world's first experimental solar power plant in the megawatt range, the construction of which was completed by the end of 1980 and which feeds electricity into the grid of ENEL, the Italian National Electricity Board, is described in detail. First operational results are presented. The costs of solar electricity, as well as means to achieve cost reductions are considered. With future total conversion efficiencies of 35% for gas/steam hybrid systems, e.g., and indicated heliostat costs of US $ 100/m 2 there is room for hope that solar thermal systems will remain competitive with photovoltaics, especially if process heat is used as a by-product.

Heat-dissipating device operated by solar energy

Abstract: This invention relates to a device using solar energy to cause a "chimney effect" to cool and refresh the interior atmosphere of a building or a vehicle. The invention further provides a modification which takes advantage of the exhaust heat of an engine so that it can operate during the night or in sunless days.

Test Procedures for Heat Storages for Solar Heating Systems

Abstract: The Danish Government supports producers of systems for renewable energy sources (solar, wind, biomass). At present the consumer will receive 30% of the investments in the installed solar heating system. In order to participate in this arrangement it is required of the producers that the components of their solar heating systems are tested. The heat storages are tested at the Thermal Insulation Laboratory at the Technical University of Denmark. Tests of marketed heat storages for solar heating systems for domestic hot water supply started in 1979, and since then the test procedures have been changed continuously according to the experience gained. The test procedure in use now and some of the experiences gained will be described in the following.

Inflation supported solar collector

Abstract: An apparatus for collecting solar energy by heating a liquid to be subsequently used for heating purposes. The liquid is injected near the top of an inflated structure and when flowing downward (by gravity) within a solar panel which is supported by the inflated structure, the liquid absorbs solar energy.