Showing papers on "Photovoltaic system published in 1978"

Merocyanine organic solar cells

Abstract: Recently, we reported on the development of a new thin‐film organic solar cell with an AM1 sunlight efficiency of about 0.7% for large area devices (∼1 cm2). This relatively high‐efficiency MIS‐Schottky barrier‐type cell was based on merocyanine type photosensitizing dyes. In this paper we present additional experimental results and develop a comprehensive theoretical model to explain the observed photovoltaic properties. The model incorporates the generation, transport, and surface dissociation of excitons and field‐dependent quantum efficiency. The low fill factor of 0.3 was attributed mainly to the field dependence of quantum efficiency. An exciton diffusion length of 60 A was determined by analyzing the short‐circuit photocurrent action spectra using the theoretical model developed. The diffusion potentials for metal/merocyanine Schottky barrier cells for six different metals were determined by C‐V measurements; the diffusion potential increases with decreasing work function. As solar cells, these dev...

Combined photovoltaic and thermal hybrid collector systems

Abstract: Solar energy collectors that produce both electric and thermal energy are an attractive alternative to individual thermal and photovoltaic collectors for certain applications and climates Economic results from a system analysis indicate that hybrid collector systems are attractive in small buildings that have substantial heating loads Passively cooled photovoltaic panels are best suited for structures located in regions where year-round air conditioning and small, low-grade, thermal energy demands predominate Hybrid collectors are to be tested according to ASHRAE standards and a full-system experiment incorporating a photovoltaic array installed at the Solar Energy Research Facility of the University of Texas will be conducted by Lincoln Laboratory

Self-reconfiguring solar cell system

Abstract: A self-reconfiguring solar cell array wherein some of the cells are switched so that they can be either in series or in shunt within the array. This feature of series or parallel switching of cells allows the array to match the load to achieve maximum power transfer. Automatic control is used to determine the conditions for maximum power operation and to switch the array into the appropriate configuration necessary to transfer maximum power to the load.

Solar power system and high efficiency photovoltaic cells used therein

Abstract: A solar power system including a movable platform for tracking the sun, a radiation concentrator, and a plurality of photovoltaic cell modules positioned on the platform for receiving concentrated solar radiation. The module includes a heat dissipation housing which supports a silicon cell across an open end of the housing. A heat transfer block physically engages the silicon cell and a metallic sponge and wick is attached to the heat transfer block and depends therefrom into the housing. The housing is partially filled with liquid to facilitate heat removal. The silicon cells are processed by preferential etching to form V grooves which define a plurality of diode elements having generally trapezoidal cross-sections. The elements may be serially interconnected by metallization on the V groove surfaces. The physical configurations of the elements and the use of antireflective coatings on surfaces of the elements result in high efficiency cells.

Solar cell materials and their basic parameters

Abstract: Parameters such as the energy gapE g , open circuit voltageV oc , short circuit current densityj sc , fill factor F.F., efficiency η, antireflection coating condition A.R. and illumination conditions of currently known photovoltaic diodes are reviewed and tabulated, followed by some critical comments.

Method and apparatus for solar power lighting

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.

Multilayer organic photovoltaic elements

Abstract: A novel multilayer, organic composition, a photovoltaic element fabricated therefrom having enhanced conversion efficiencies, and their use to generate power, are disclosed. Compounds with generally planar polycyclic nuclei such as organic photoconductive dyes comprise the several layers of the composition.

Focusing cover solar energy collector apparatus

Abstract: A solar energy collector apparatus and method, the apparatus including an open-top shell structure configured with either an enclosed or lattice configuration and having a Fresnel lens system covering the open top of the shell structure. A mirror system and solar energy absorber apparatus are placed inside the shell structure. The shell structure is mounted upon a hollow axle for rotation about its longitudinal axis. The shell structure is also mounted for vertical movement of one end of the longitudinal axis to adapt the shell structure for following north-south changes in the sun's seasonal position. The hollow axle supports the solar energy absorber apparatus nonrotatably inside the shell structure and in fluid communication with insulated heat transfer conduits that pass nonrotatably through the hollow axle. A photovoltaic apparatus may be included in the shell structure for converting at least a portion of the solar flux to electrical energy while the heat transfer conduits supply any necessary cooling to the photovoltaic apparatus. This combination of features provides higher solar efficiencies and higher temperatures in the heat transfer fluid. The method includes tracking the sun with the solar energy collector apparatus thereby maximizing the amount of solar energy collected while eliminating twisting and thereby coupling failures in the heat transfer conduits.

Luminescent solar collector structure

Abstract: Disclosed is a luminescent solar collector optically coupled to a photovoltaic cell and in confronting relationship thereto a diffusing layer of a particulate phosphorescent material deposited on and backed by a mirror.

Tracking booster and multiple mirror concentrator floating collector

Abstract: A water-borne tracking solar energy collecting and converting system employing booster and multiple mirror concentrator collectors for concentrating sunlight on either photovoltaic cells and/or flat plate collectors.

Integrated residential and automotive energy system

Abstract: An integrated system including a residence and an automobile utilizes environmental energy, such as solar energy, as the primary energy source, and the automobile provides a backup or supplementary source of energy for this system. An exemplary system has photovoltaic and thermal collectors associated with the residence for collecting radiant solar energy and converting a portion thereof to electricity and to heat, and residential energy storage means for storing energy generated within the integrated energy system; hybrid electric drive means associated with the automobile in this exemplary system includes batteries for storing electrical energy generated within the integrated energy system, an electrically energized motor to propel the automobile, and a liquid-fueled combustion engine for driving an associated electrical generator to function as a backup or supplementary source of energy for both the residence and the automobile. Interface umbilicals interconnect the residence and the automobile to enable energy to be selectively transferred from the residence to the automobile, and from the automobile to the residence, under the control of suitable sensing and control circuits.

Solar tracking device

Abstract: An improved solar tracking arrangement is provided for directing a solar energy collector to face the sun. An electrical control mechanism is provided to detect misalignment of the collector as the sun traverses in relative movement across the sky. When the misalignment exceeds an adjustable limit of tolerance, the tracking system moves the collector to an orientation slightly in advance of the current position of the sun by an amount equal to the limit of tolerance. A threshold light level is required to activate the tracking system, and differential photosensors are employed, the composite signals of which compensate for variations in ambient light level so that the amount of surrounding illumination of the environment does not effect the preset limit of tolerance. The tracking system includes east and west limit switches, which reorient the collector to an eastward facing direction at the end of each day. A high temperature cut off is provided to direct the collector away from the sun when the operating temperature of the collector exceeds a predetermined limit of safety. For self-contained operation, photovoltaic cells are mounted on the collector to provide electricity for the tracking system.

Structure for conversion of solar radiation to electricity and heat

Abstract: Disclosed is a structure which in one apparatus converts a part of incident solar energy to electrical energy by the use of photocells mounted on a luminescent solar collector of tubular design while another portion of such incident energy is converted to thermal energy.

Internal refractor focusing solar energy collector apparatus and method

Abstract: A solar energy collector apparatus and method, the apparatus including an open-top shell-like structure. A Fresnel lens system and a mirror system inside the shell structure focus and direct solar energy toward a solar energy absorber apparatus also inside the shell structure. The shell structure is mounted upon a hollow axle in a framework for rotation about its longitudinal axis. The framework supports the longitudinal axis in a position generally parallel to the axis of rotation of the earth to provide an equatorial mounting for the solar energy collector. Rotation about the longitudinal axis adapts the solar collector for following the east-west movement of the sun. The optical apparatus in the shell structure is adapted for movement to follow the north-south seasonal changes in the sun's position. The solar energy absorber apparatus is nonrotatably supported inside the shell structure by the hollow axle and heat transfer conduits pass through the hollow axle to the solar energy absorber apparatus in nonrotable relationship therewith. A photovoltaic apparatus may be included within the shell structure for converting at least a portion of the incoming solar spectrum to electrical energy. This combination of features provides higher solar efficiencies and higher temperatures in the heat transfer fluid. The method includes tracking the sun with the solar energy collector apparatus thereby maximizing the amount of solar energy collected while eliminating coupling failures in the heat transfer conduits.

Solar cell battery charging control system

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.

A possible explanation for the photovoltaic effect in indium tin oxide on InP solar cells

Abstract: Recently, Sree Harsha and co‐workers reported a 14.4% efficient n‐indium tin oxide/p‐InP solar cell. In principle, it is difficult to visualize a high‐efficiency photovoltaic device with this particular structure because of large interfacial defects due to crystal structure and lattice mismatch. However, we propose an explanation for the operation of this solar cell based on the presence of a thin interfacial insulating layer between the indium tin oxide and the InP. The operation is similar to tunnel MIS solar cells where the metal is replaced by a degenerate wide‐band‐gap oxide (indium tin oxide) semiconductor. Our calculations show that such semiconductor‐insulator‐semiconductor solar cells can yield efficiencies as high as 26% (AM2) with InP as the base semiconductor.

Universal solar cell/conductor junction element and solar panel embodying same

Abstract: A solar electric power generating panel (solar panel) includes one or more universal electrical junction elements of approximately the same size and shape as conventional solar cells mounted along with the cells on a solar array substrate at any selected cell position or positions of the cell array. Each junction element has terminals which may be electrically connected to interconnects of the solar cells and electrical conductors such as lead wires of the cell array in such a way as to condition the element to serve as a series string termination with or without blocking diodes, an electrical voltage tap with or without blocking diodes, or a mounting for cell shunting diodes. Automatic assembly tooling may be utilized to assemble and electrically connect the solar cells, conductors, and junction elements into a completed solar array.

Silicon photovoltaic cells in thermophotovoltaic energy conversion

Abstract: A new silicon photovoltaic cell has been developed for use in a thermophotovoltaic (TPV) energy converter. Attention has been paid to minimizing parasitic absorptance and optimizing electrical performance. Energy conversion efficiencies of 26 percent in TPV operation were measured at an output power density of 10 W/cm2.

Solar collector structures containing thin film polysiloxane, and solar cells

Abstract: Disclosed is a composite collector and concentrator structure comprising a laminate having a self-supporting layer of solid light transmitting material of extended area in one plane in optical contact with a relatively thin layer of a silicone resin derived from a trifunctional silane containing at least one species of luminescent material which absorbs electromagnetic radiation and emits electromagnetic radiation of a longer wave length. Use with photovoltaic solar cells is also disclosed.

System for the multipurpose utilization of solar energy

Abstract: A solar energy system where the incident solar radiation evaporates a quantity of water in a distillation pond; the water vapor/air mixture rises buoyantly through a duct to a high elevation where it drives a wind turbine to produce electricity; the water is condensed out of the mixture and stored in a high elevation reservoir, where it is used to drive hydro-electric turbines; spent water is stored at a low elevation and is used for drinking, irrigation or recycling to the distillation pond.

Converting solar energy into electric power

Abstract: A method for converting solar energy into electric power is disclosed, in which air, preheated and precompressed is additionally heated in a solar heater and sent to work in a turbine unit connected to an electric power generator.