Showing papers on "Photovoltaic thermal hybrid solar collector published in 1994"
TL;DR: The Solar Engineering of Thermal Processes (SEPTP) as discussed by the authors has become a classic solar engineering text and reference for students of solar engineering, solar energy, and alternative energy as well as professionals working in the power and energy industry or related fields.
Abstract: The updated fourth edition of the "bible" of solar energy theory and applications
Over several editions, Solar Engineering of Thermal Processes has become a classic solar engineering text and reference. This revised Fourth Edition offers current coverage of solar energy theory, systems design, and applications in different market sectors along with an emphasis on solar system design and analysis using simulations to help readers translate theory into practice.
An important resource for students of solar engineering, solar energy, and alternative energy as well as professionals working in the power and energy industry or related fields, Solar Engineering of Thermal Processes, Fourth Edition features:
Increased coverage of leading-edge topics such as photovoltaics and the design of solar cells and heatersA brand-new chapter on applying CombiSys (a readymade TRNSYS simulation program available for free download) to simulate a solar heated house with solar- heated domestic hot waterAdditional simulation problems available through a companion websiteAn extensive array of homework problems and exercises
798 citations
TL;DR: In this paper, a theoretical study of a hybrid photovoltaic cum thermal (PV/T) solar system is presented, where air/water is made to flow in a duct placed below the surface on which the solar cells are mounted to extract heat from the system, thereby cooling the cells and increasing their efficiency.
212 citations
Patent•
28 Nov 1994
TL;DR: In this paper, an electric power supply system consisting of an air conditioner serving as load, a solar photovoltaic cell for supplying power to the air conditioning system, and a system power control circuit was described.
Abstract: This electric power supply system includes an air conditioner serving as load, a solar photovoltaic cell for supplying power to the air conditioner, and a system power control circuit and further including a commercial power source for use in combination with the solar photovoltaic cell for supplying additional power when insufficient, power is supplied from the solar photovoltaic cell to the air conditioner In an operation state of the air conditioner, the system power control circuit operates to regulate an operating point of the solar photovoltaic cell and variably regulate the supplied power from the solar photovoltaic cell while comparing required power of the air conditioner with the supplied power from the solar photovoltaic cell
109 citations
Patent•
25 Nov 1994TL;DR: In this article, a solar cell is used without any additional base to limit the reduction in the conversion efficiency of the solar cell, and a passive solar heating system is used to obtain a greater amount of clean energy.
Abstract: A solar cell module in which the reduction in conversion efficiency is small, and a passive solar heating system using the solar cell module. The solar cell module has a solar cell covered with a filler. A back reinforcement member, the filler and a back insulating member larger than the solar cell are superposed on the non-light-receiving side of the solar cell. The back insulating member has openings corresponding to pierced portions of the solar cell module at which the solar cell module is affixed to a roof. A greater amount of clean energy is obtained with the system. The solar cell is used without any additional base to limit the reduction in the conversion efficiency of the solar cell.
108 citations
Patent•
12 Apr 1994TL;DR: In this article, a power plant consisting of an array of heliostats for concentrating sunlight on a central solar receiver is described. And a thermal shield is employed over the solar central receiver to insulate the solar receiver, provide leak and fire protection and shield the solar primary receiver from solar radiation.
Abstract: A design of a power plant which uses hydrocarbon fuels in conjunction with solar power to produce electricity. The power plant consists of an array of heliostats for concentrating sunlight on a central solar receiver. The heat energy thus gathered is used to create steam which runs a steam turbine. Steam to run the steam turbine can alternately or modularly be obtained from the exhaust gas of a turbo-burner and fuel added to a furnace. The solar energy gathered may be stored as hot fluid in a thermal storage tank or used immediately in the power plant. A thermal shield may be employed over the solar central receiver to insulate the solar central receiver, provide leak and fire protection and shield the solar central receiver from solar radiation.
106 citations
Patent•
20 Jun 1994
TL;DR: In this article, a power generating system comprises a solar concentrator defining an effectively concave reflective surface on a surface of the earth for concentrating incoming solar energy, and a solar collector is disposed in an underground chamber provided with an access opening.
Abstract: A power generating system comprises a solar concentrator defining an effectively concave reflective surface on a surface of the earth for concentrating incoming solar energy. A solar collector is disposed in an underground chamber provided with an access opening. The solar collector receives solar energy concentrated by the concentrator and converting the concentrated solar energy to another energy form, generally thermal energy, which is subsequently convertible to electrical power. Directional componentry is provided for directing concentrated solar energy from the concentrator along a predefined folded transmission path through the access opening to the collector.
90 citations
TL;DR: In this article, the authors present an experimental study of a thermosyphon water heater with solar cells, where the solar cells are pasted directly over the absorber plate and the solar insolation falling on the aperture area of the collector, using a simple parabolic reflector.
89 citations
TL;DR: In this article, the authors used a finite difference method to simulate the performance of a solar water heater with photovoltaic thermal (PV/T) cells and showed that the average cell efficiency is more or less independent of the cell area.
71 citations
TL;DR: The Fraunhofer Institute for Solar Energy Systems has built a completely self-sufficient solar house (SSSH) in Freiburg, Germany as discussed by the authors, where the entire energy demand for heating, domestic hot water, electricity, and cooking is supplied by the sun.
61 citations
TL;DR: In this paper, the authors proposed a method of not decreasing cell conversion efficiency with collecting solar thermal energy was proposed based on this evaluation, and evaluated the electric and thermal energy obtained from a PV/T panel is evaluated in terms of energy.
TL;DR: In this article, numerical simulations are used to get a closer insight into the transient response behavior of these elegant, but rather complicated systems during variable insolation conditions and to estimate the overall system performance accurately over extensive periods of time.
TL;DR: In this paper, a V-trough solar concentrator was combined with an inclined flat-plate wick-type solar still for outdoor testing on clear days in summer and winter.
Patent•
23 Sep 1994
TL;DR: In this paper, a hybrid combined cycle power plant including a solar central receiver for receiving solar radiation and converting it to thermal energy is described. But the power plant includes a molten salt heat transfer medium for transferring the thermal energy to an air heater, and the air heater is used to preheat the air from the compressor of the gas cycle.
Abstract: A hybrid combined cycle power plant including a solar central receiver (7) for receiving solar radiation and converting it to thermal energy The power plant includes a molten salt heat transfer medium (8) for transferring the thermal energy to an air heater (9) The air heater (9) uses the thermal energy to preheat the air from the compressor (12) of the gas cycle The exhaust gases from the gas cycle are directed to a steam turbine (16) for additional energy production
TL;DR: In this paper, the authors focused on solar thermal electricity generation and such promising technologies as trough collectors, tower plants, solar chimneys and Dish/Stirling systems, and showed that the de...
Abstract: This paper concentrates on solar thermal electricity generation and such promising technologies as trough collectors, tower plants, solar chimneys and Dish/Stirling systems. It is shown that the de...
TL;DR: In this article, the p-n junction was formed from a phosphorus-doped spin-on silica film deposted on (100) silicon substrates at typical processing temperatures between 800 and 1100°C.
Abstract: Rapid thermal processing can offer many advantages, such as small overall thermal budget and low power and time consumption, in a strategy focused on cost-effective techniques for the preparation of solar cells in a continuous way. We show here that this very short duration (a few tens of seconds) of isothermal heating performed in a lamp furnace can be used for many thermal steps of silicon solar cell processing. Rapid thermal processing was applied to form the p-n junction from a phosphorus-doped spin-on silica film deposted on (100) silicon substrates at typical processing temperatures between 800 and 1100°C. the solar cells showed conversion efficiencies as good as those processed in a conventional way.
TL;DR: In this paper, the authors used the F-chart technique to evaluate three types of solar heating systems, namely, space solar heating and domestic hot water system (SHDHW), domestic hotwater system (DHW) and solar swimming pool heating system (SPHS), using three different concrete solar collectors, models A, B, and C, and one conventional metallic solar collector.
05 Dec 1994
TL;DR: In this article, the authors demonstrate that a-Si:H PV modules are best suited for cogeneration because they behave as if they had a positive temperature coefficient, and they then study the potential savings and return on investment of an "Ecothel" installation connected to the grid of a private home using electric space heating like most of the modern houses in France and a commercial building with air conditioning.
Abstract: This study relates to the performance tests of a 66% efficient hybrid solar module "Capthel", and to the economic study of the combined generation of solar electricity and hot air ("Ecothel" solar cogeneration). The authors demonstrate that a-Si:H PV modules are best suited for cogeneration because they behave as if they had a positive temperature coefficient. They report experimental results on the first prototype and describe further improvements in the design of the thermal collector. They then study the potential savings and return on investment of an "Ecothel" installation connected to the grid of a private home using electric space heating like most of the modern houses in France and a commercial building with air conditioning.
05 Dec 1994
TL;DR: In this article, a concentrating and splitting system based on a Cassegrainian design was used for photovoltaic energy conversion and simultaneously for an additional energy conversion process such as for laser pumping that requires concentration.
Abstract: Several solar energy conversion processes can be utilized simultaneously using a common solar collector if the solar radiation is appropriately spectrally split. A concentrating and splitting system based on a Cassegrainian design may be used for photovoltaic energy conversion and simultaneously for an additional energy conversion process such as for laser pumping that requires concentration. The spectral splitting may be achieved by a dichroic mirror for the secondary mirror of the Cassegrain. This approach was realized to study solar cells at different concentration, solar spectrum and temperatures.
TL;DR: In this article, the design characteristics of a transparent honeycomb insulation device are presented and the performance of some transparently insulated solar thermal systems using water and ground (concrete/sand) as storage media is investigated for energy conservation applications.
Abstract: Design characteristics of a transparent honeycomb insulation device are presented and the performance of some transparently insulated solar thermal systems using water and ground (concrete/sand) as storage media is investigated for energy conservation applications. Simulation results of honeycomb solar ponds predict solar collection efficiencies of up to 40–60% at temperatures of 70–90°C. Field experiences with water storage cubes and cuboid using the transparent insulation on the surface and peripheries suggest that incorporating the transparent insulation on the central open cut would provide the benefits of added solar gain and thermal storage. The use of ground (sand/concrete) as the solar collector-storage media in the above application enables heat ( ΔT = 50° C ) to be collected at a solar conversion efficiency of about 40%.
TL;DR: In this paper, a self-contained solar heating forced water cooling unit was selected and assembled, consisting of three flat-plate solar collectors, each of area 1.2 m 2, a.c. pump, a photovoltaic module and a storage tank.
TL;DR: In this paper, finite-time thermodynamics has been applied to solar heat engines in order to find the optimum operating temperature for solar thermal power systems, and the percentage difference between optimum operating temperatures based on Curzon-Ahlborn (CA) efficiency and classical Carnot efficiency has been presented.
Abstract: In this paper, finite-time thermodynamics has been applied to solar heat engines in order to find the optimum operating temperature for solar thermal power systems. The percentage difference between optimum operating temperatures based on Curzon-Ahlborn (CA) efficiency and classical Carnot efficiency has been presented. This analysis has also been used to find the upper bound on efficiency for a wide range of the operating temperatures characterising various solar thermal power systems.
TL;DR: In this paper, the thermal analysis of a distillation unit under the active mode of operation has been presented, where the basin of the solar still unit has been integrated with the panel of collectors through a tube-in-tube heat exchanger with provision of two pumps, one each in the collector and solar still loops.
Patent•
17 Sep 1994TL;DR: The solar heater head for absorption of the concentrated radiation of a solar concentrator for transmission of this heat on to the working gas of a Stirling engine or another type of thermal power machine is described in this paper.
Abstract: The solar heater head for absorption of the concentrated radiation of a solar concentrator for transmission of this heat on to the working gas of a Stirling engine or another type of thermal power machine In order to provide a heater head giving good concentration of the solar radiation, with reduced thermal and optical losses, and to provide safety against local overheating, at least one body (1;9) made of good heat conducting material and at least blackened on the side facing the radiation is provided as a solar absorber, a heat conducting structure for spatial evaluative comparison of the thermal flows and serving as a short-term store for homogenising the thermal fluxes
01 Oct 1994
TL;DR: The U.S. National Renewable Energy Laboratory (NREL) developed solar reflector materials that maintain high specular reflectance for extended lifetimes under outdoor service conditions and whose cost is significantly lower than existing products as discussed by the authors.
Abstract: This paper describes the research and development program at the U.S. National Renewable Energy Laboratory (NREL) in advanced reflector materials for solar concentrators. NREL's research thrust is to develop solar reflector materials that maintain high specular reflectance for extended lifetimes under outdoor service conditions and whose cost is significantly lower than existing products. Much of this work has been in collaboration with private-sector companies that have extensive expertise in vacuum-coating and polymer-film technologies. Significant progress and other promising developments will be discussed. These are expected to lead to additional improvements needed to commercialize solar thermal concentration systems and make them economically attractive to the solar manufacturing industry. To explicitly demonstrate the optical durability of candidate reflector materials in real-world service conditions, a network of instrumented outdoor exposure sites has been activated.
TL;DR: In this article, the spectral response of various photovoltaic modules was used to evaluate the maximum amount of output in photovolastic modules, and the spectral method proved most effective for optimum design of amorphous silicon PV power systems.
Abstract: For the optimum design of photovoltaic power systems, it is very important to estimate their annual maximum amount of output. In general, the annual maximum amount of output has been calculated by using photovoltaic module efficiency under irradiance of 1 kW/m2 at AM 1.5 with solar cell temperature of 25°C. Since the spectral distribution of solar radiation changes with weather, season and time, the efficiency of solar cells is not always constant.
This paper describes a method evaluating the maximum amount of output in photovoltaic modules, ‘the spectral method,’ by using the measured annual spectral solar radiation and the spectral response of various photovoltaic modules.
The calculated values using the spectral method agreed well with the measured values for amorphous silicon photovoltaic modules from March 1991 to February 1992. The spectral method proved most effective for optimum design of amorphous silicon photovoltaic power systems.
01 Nov 1994
TL;DR: In this article, the authors investigated the technical feasibility of solar cooling for peak demand reduction using a building energy simulation program (DOE2.1D) and showed that, on the day with peak cooling load, about 17% of the peak load could be met satisfactorily with the solar-assisted cooling system without any thermal storage.
Abstract: We investigated the technical feasibility of solar cooling for peak demand reduction using a building energy simulation program (DOE2.1D). The system studied was an absorption cooling system with a thermal coefficient of performance of 0.8 driven by a solar collector system with an efficiency of 50% with no thermal storage. The analysis for three different climates showed that, on the day with peak cooling load, about 17% of the peak load could be met satisfactorily with the solar-assisted cooling system without any thermal storage. A performance availability analysis indicated that the solar cooling system should be designed for lower amounts of available solar resources that coincide with the hours during which peak demand reduction is required. The analysis indicated that in dry climates, direct-normal concentrating collectors work well for solar cooling; however, in humid climates, collectors that absorb diffuse radiation work better.