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Showing papers on "Grid-connected photovoltaic power system published in 1978"


Patent
11 Dec 1978
TL;DR: In this article, a plurality of solar cells are disposed in an array about an upstanding light pole of conventional design of the type having a hollow interior and laterally extending lighting elements.
Abstract: Solar powered and/or augmented lighting systems embodied within conventional hollow light pole configuration incorporating a solar power lamp cell. A plurality of solar cells are disposed in an array about an upstanding light pole of conventional design of the type having a hollow interior and laterally extending lighting elements. The lighting element itself is provided in a configuration incorporating a solar cell atop a storage battery atop a light source, such as a bulb, operable from said light power system. The lighting cell is selectively powered by either a storage battery system operable in conjunction with the solar panel array and/or the solar power network incorporated therein. A network of electrical storage cells are disposed within the hollow configuration of the light pole and supported upon an elevator system for facilitating access thereto. In this manner, the overall consumption of energy from conventional power lines may be reduced and/or eliminated. The commercial lines may remain connected to said light poles for augmented power during periods of low solar energization and for purposes of original solar collector orientation.

86 citations


Patent
12 May 1978
TL;DR: In this article, a solar cell battery charging control system has been proposed, which consists of a storage battery and a plurality of solar cells connected in series for charging the storage battery, which system comprises a heavy load means adapted to be driven by the battery to discharge the battery when a battery charge level exceeds a predetermined value.
Abstract: A solar cell battery charging control system having a storage battery and a plurality of solar cells connected in series for charging the storage battery, which system comprises a heavy load means adapted to be driven by the storage battery to discharge the storage battery for thereby preventing overcharging of the storage battery when a battery charge level exceeds a predetermined value.

40 citations


Journal ArticleDOI
TL;DR: In this paper, the design of the mirror field for the CNRS (Centre National de la Recherche Scientifique) project of a several MWe solar energy conversion power plant, an analysis of this concentration system is proposed.

7 citations


Journal ArticleDOI
TL;DR: In this article, the state-of-the-art of photovoltaic power systems, for use in synchronous-orbit spacecraft, is characterized, including solar array, battery, and power control component performance.
Abstract: The state-of-the-art of photovoltaic power systems, for use in synchronous-orbit spacecraft, is characterized, including solar array, battery, and power control component performance. Advanced developments in each of these areas are reviewed, and performance improvement projections are made for the 1980-1990 time period. It is estimated that photovoltaic power system specific weight could improve from a present value of 126 kg/kW to approximately 43 kg/kW in 1985. These performance predictions are compared to nuclear system performance projections over the same period. The analysis indicates that advanced photovoltaic power systems will exhibit specific weights lower than isotope and nuclear reactor systems for power levels up to approximately 25 kW. At higher power levels, batteries with higher energy density would be required to compete with the projected performance of advanced nuclear systems. N this paper, we review state-of-the-art performance characteristics of synchronous-orbit power system components, discuss technology advancements, extrapolate overall system performance into the 1980-1990 time period, and finally, make alternative power system comparisons. Power subsystem performance improvement areas include solar array power density, battery energy density, and power control electronics power density. These components typically comprise 15-20% of total spacecraft weight. Increased spacecraft payload weight allocation and total system capability improvement will result from power system weight reduction.

3 citations


01 Nov 1978
TL;DR: In this paper, a concept for generating high-efficiency, low-cost, solar-cell power is outlined with reference to solar cell parameters, optical concentrators, and thermal control procedures.
Abstract: A concept for generating high-efficiency, low-cost, solar-cell power is outlined with reference to solar cell parameters, optical concentrators, and thermal control procedures A design for a 125-kw power module for space operation is discussed noting the optical system, spectrum splitter, light conversion system, cell cooling, power conditioner, and tracking mechanism It is found that for an unconcentrated array, efficiency approaches 60% when ten or more bandgaps are used For a 12-band system, a computer program distributed bandgaps for maximum efficiency and equal cell currents Rigid materials and thin films have been proposed for optical components and prisms, gratings, and dichroic mirrors have been recommended for spectrum splitting Various radiator concepts are noted including that of Weatherston and Smith (1960) and Hedgepeth and Knapp (1978) The concept may be suitable for the Solar Power Satellite

3 citations


Journal ArticleDOI
TL;DR: In this article, an account is given in general terms of the various types of solar powered devices that are now available with present technology and electrical and non-electrical energy convertors are described as is the possibility of solar power stations.
Abstract: An account is given in general terms of the various types of solar powered devices that are now available with present technology. Electrical and non-electrical energy convertors are described as is the possibility of solar power stations.

2 citations



01 Jan 1978
TL;DR: In this article, 16 geographically dispersed photovoltaic systems are described in terms of load requirements, solar array and battery size, and instrumentation and controls, and present status is given for each system.
Abstract: Designed, fabricated and installed were 16 geographically dispersed photovoltaic systems. These systems are powering a refrigerator, highway warning sign, forest lookout towers, remote weather stations, a water chiller at a visitor center, and insect survey traps. Each of these systems is described in terms of load requirements, solar array and battery size, and instrumentation and controls. Operational experience is described and present status is given for each system. The P/V power systems have proven to be highly reliable with almost no problems with modules and very few problems overall.

2 citations


Journal ArticleDOI
J. Bany1
01 Jan 1978
TL;DR: The motor characteristics—current-speed and torque-speed at different solar radiation levels—were studied and the performance of direct current motors-separate, series and shunt excitation, supplied from a solar cell array was studied.
Abstract: Applications of photovoltaic solar energy conversion are increasing, and among them are systems of electric motors coupled to solar cell arrays, such as for water pumping. A study of the interaction of the photovoltaic converter and the electric drive is needed for these systems. This paper deals, therefore, with the performance of direct current motors-separate, series and shunt excitation, supplied from a solar cell array. The motor characteristics—current-speed and torque-speed at different solar radiation levels—were studied.

2 citations


01 Jan 1978
TL;DR: In this article, the authors compared the costs of all-diesel, all-solar, and hybrid (solar + petrol generator as standby) systems for isolated rural consumers in Australia.
Abstract: The costs of photovoltaic conversion of solar energy to electricity are lessening. Thus solar electric power is being utilized in different areas. Isolated rural consumers are potential candidates for solar power. Comparisons of generation costs for three systems for isolated rural consumers in Australia are presented. These are an all-diesel, all-solar and hybrid (solar + petrol generator as standby) system. Based on the 1978 projected price of $2/We (peak) for solar cell arrays, it is shown that the hybrid system is almost competitive with the all-diesel system. For the 1986 projected price of 50c/We (peak) it is shown that the hybrid system is twice as economical as the all-diesel system. In both cases the all-solar system suffers from the cost of storage. Solar electric power can be used to raise the standard of living of rural people in the less-developed countries. There are immediate uses for solar power now. Research being undertaken at the University of New South Wales on metal-insulator-semiconductor solar cells is described briefly.

2 citations


01 Jan 1978
TL;DR: In this paper, the nominal effects of energy storage on cost and performance goals for solar photovoltaic conversion systems intended for large-scale electric utility applications are studied with respect to dispatch modes that either dedicate the energy storage to the plant operation to achieve a given plant capacity factor or treat the storage as utility system asset to be dispatched independent of the solar system.
Abstract: The nominal effects of energy storage on cost and performance goals for solar photovoltaic conversion systems intended for large-scale electric utility applications are studied. Specifically, central station photovoltaic power plants having co-located energy storage systems are examined with respect to dispatch modes that either dedicate the energy storage to the plant operation to achieve a given plant capacity factor or treat the energy storage as a utility system asset to be dispatched independent of the solar system. Resultant system economics are treated parametrically with respect to photovoltaic array efficiency, average solar insolation, and energy storage efficiency. It is concluded that dedicated energy storage imposes a severe economic and performance penalty on the allowable cost of photovoltaic arrays for intermediate load utility applications.

01 Feb 1978
TL;DR: In this paper, the effects of input shunt capacitance and series inductance on the efficiency and power factor of a solar array were evaluated with an 8-kilowatt (kW) inverter.
Abstract: Efficiency and power factor were measured as functions of solar array voltage and current. The effects of input shunt capacitance and series inductance were determined. Tests were conducted from 15 to 75 percent of the 8 kW rated inverter input power. Measured efficiencies ranged from 76 percent to 88 percent at about 50 percent of rated inverter input power. Power factor ranged from 36 percent to 72 percent.