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03815 Triple basin active solar still
07
Radiation resistance of high-efficiency InGaPlGaAs 99103807 tandem solar cells Takamoto, T. et al. Solar Energy Materials & Solar Cells, 1999, 58, (3), 265216. Radiation resistance of high-efficiency InGaP/GaAs tandem solar cells with a world-record efficiency of 26.9% (AMO, 28°C) has been evaluated by 1 MeV electron irradiation. Degradation in tandem cell performance has been confirmed to be mainly attributed to large degradation in the GaAs bottom cell. Similar radiation resistance with GaAs-on-Ge cells has been observed for the InGaP/GaAs tandem cell. Moreover, recovery of the tandem cell performance has been found due to minority-carrier injection under light illumination or forward bias, which causes defect annealing in InGaP top cells. The optimal design of the InGaP base layer thickness for current matching at end of life (EOL) (after irradiation with 10” electrons cm-‘) has been examined.
Rellabllity of rechargeable batteries In a photovoltsic power supply system
99103808
Urbina, A. er al. J. Power Sources, 1999, 80, (l/2), 30-38. The reliability of a rechargeable battery acting as the energy storage component in a photovoltaic power supply system was investigated. A model system was constructed that includes the solar resource, the photovoltaic power supply system, the rechargeable battery and a load. The solar resource and the system load are modelled as stochastic processes. The photovoltaic system and the rechargeable battery are modelled deterministically and an artificial neural network is incorporated into the model of the rechargeable battery to simulate damage that occurs during deep discharge cycles. The equations governing system behaviour are solved simultaneously in the Monte Carlo framework and a first passage problem is solved to assess system reliability.
Sinusoidal spectral correction for high precision outdoor module characterization
99103809
Berman, D. et al. Solar Energy Materials & Solar Cells, 1999, 58, (3), 253264. This paper presents the results of experiments which demonstrate that a sinusoidal variation in the long-term, STC-corrected, outdoor performance of PV modules is caused by seasonal spectral changes in the received sunlight. This variation may be factored out to increase the precision of outdoor studies. This result is used (a) to quantify the rate of EVA degradation observed in the Negev desert under natural l-sun conditions and (b) to identify a principal source of the summer recovery observed in modules of amorphous silicon cells.
Solar desalination based on humidification process 99iQ3810 I. Evaluating the heat and mass transfer coefficients
Nawayseh, N. K. et al. Energy Comers. Manage., 1999,40, (13), 1423-1439. For the production of fresh water from saline or sea water, solar desalination with a humidification-dehumidification process has proven to be an efficient means of utilizing solar energy. The process used in this work is a closed air cycle type, in which air is circulated in the unit by natural draft between the humidifier and condenser. In order to scale up a unit of this type, it is necessary to obtain sufficient information on the process of heat and mass transfer in the unit. The humidifier and the condenser had to be specially designed to maintain minimum pressure drop in the unit. The mass transfer coefficient in the humidifier was found to be affected mostly by the water flow rate due to its effect on the wetting area of the packing. In natural draft operation, the air circulation rate was found to increase with water flow rate, causing a further increase in the mass transfer coefficient. It was possible to predict and correlate the mass and heat transfer coefficients in the humidifiers and condensers, having different designs, in the three units constructed by the authors in Jordan and Malaysia.
Solar desalination based on humidification process II. Computer simulation
99lO3811
Nawayseh, N. K. el al. Energy Cowers. Manage., 1999,40, (13), 1441-1461. Solar desalination requires an efficient method of evaporation and condensation at relatively low temperatures. This could be suitably achieved in a humidification/dehumidification process using circulated air to enhance evaporation of the water. With proper utilization of the latent heat of condensation of water vapour, the process efficiency could be made high. In order to optimize the design of such a desalination unit, a simulation programme was constructed in which the set of non-linear equations describing the desalination unit were solved numerically. The results of the simulation were in agreement with the experimental results of two different units constructed in Jordan and Malaysia. The performance of each unit was tested when they were operated with an energy obtained either from solar or an electrical heating source. The air flow rate was found to have an insignificant effect on the productivity of desalinated water. The simulation allows the proper choice of the feed water flow rate to the unit.
99103812
Solar domestic water heating in Turkey
Akinoglu, B. G. er al. Energy, 1999, 24, (5). 363-374. The present situation of solar water heating for domestic supplies in Turkey is discussed and the results of a computer analysis for nine distinct regions are given. The analyses are carried out for four typical days of the four seasons and also on a monthly base. The results show that detailed initial work must be carried out before installing the system to determine the
Alternative
energy sources (solar energy)
optimized collector area. Such analysis can provide efficient usage of the sun’s energy as well as economical benefits in the initial investments and long-term utilization.
99103013 Solar processing of materials: opportunities and new frontiers
Flamant, G. er al. Sofur Energy, 1999, 66, (2). 117-132. The paper presents the synthesis of materials with unique properties or with a high chemical selectivity as a competitive application domain for concentrated solar energy, with respect to laser or plasma systems. To illustrate the general arguments, recent experimental data are presented in three domains: (1) surface hardening of steel, (2) oxides nanopowder processing and (3) fullerenes and nanotubes synthesis. The results obtained with 25 kW solar furnaces are evaluated in view of solar process scaling-up.
A solar-powered ice-maker with the solld adsorption pair qf activated carbon and methanol
99103814
Li, Z. F. and Sumathy, K. Int. J. Energy Res., 1999, 23, (6), 517-527. Presented here are the description and operation of a solar-powered icemaker with the solid adsorption pair of activated carbon and methanol. A domestic type of charcoal was chosen as the adsorbent and a simple flatplate collector with an exposed area of 0.92 m* was employed to produce ice of about 45 kg d-’ at an evaporator temperature of about -6°C. The above system could achieve solar refrigeration COP of about 0.1-0.12. With the description of the idealized refrigerating system, the influences of evaporating temperature, adsorbing temperature and condensing temperature on the COP were also analysed.
99io3015 Triple basin active solar still Kumar, S. and Tiwari, G. N. hr. J. Energy Res., 1999, 23, (6), 529-542. In order to solve three coupled differential equations to determine the performance of an active triple basin solar distillation system, the RungeKutta method was used. Hourly variation of various temperatures and yield have been evaluated along with overall thermal efficiency. Optimization of various parameters, namely collector and basin area and water depth with respect to daily yield, has been carried out. Numerical computations have been performed for a typical day of Delhi climate. On the basis of numeric results, it has been observed that optimization of the collector area reduces with a number of effects.
99103816 The use of corrugated booster reflectors for solar collector fields Rannelid, M. and Karlsson, B. Solar Ener~, 1999, 65, (6), 343-351. The use of booster reflectors in front of solar collectors is an established technique for increasing the irradiation onto solar collectors. By using corrugated instead of flat booster reflectors, it is possible to increase the annual irradiation onto the collector plane, thereby maximizing the annual output from the collector-reflector arrangement. The paper includes a description of a ray tracing programme which calculates the annual optical performance of a collector-booster reflector system with different Vcorrugated reflectors. Based on Swedish solar radiation data, calculations show that the use of a booster reflector with varying V-corrugations along the reflector, instead of a flat booster reflector, can increase the annual reflected direct radiation on to the collector by 10%. This is estimated to result in a 3% increase in the annual collector output. The ray-tracing calculations are compared with measurements of the reflection characteristics of single V-shaped reflector arrangements.
99103817 The 1998 World Solar Rallye: Akita, Japan Shacklock, A. et al. J. Power Sources, 1999, 80, (l/2), 199-206. Eighty-one solar/electric vehicles participated in a three day endurance race in Japan in August 1998, aiming to complete as many laps of the 31 km circuit as possible. Some of the cars used state-of-the-art motors, batteries, chassis, solar cells and tyres to produce vehicles which could travel at speeds of 70-80 km/h on about 1 kW of input power. With only 20 kg of battery, some solar cars were travelling around 450 km a day. This paper tells the story of the race and the technological developments behind the successful vehicles.
99/03818 X-ray fluorescence measurements of thin film chalcopyrite solar cells Fiyk,
M. et al.
Solar Energy Materials & Solar Cells, 1999, 58, (3), 299-
X-ray fluorescence has turned out to be a very suitable and reliable tool for the characterization of thin film chalcopyrite solar cells. Besides the composition determination in atomic percent, the total mass per unit square (mg/cm2) of the analysed elements and the film thickness can be measured accurately. Furthermore, a real multi-layer analysis allows in addition to determine the CdS, ZnO and MO thickness simultaneously with the absorber measurement. By the use of etching techniques, information about a vertical composition gradient can also be obtained. This work shows the possibilities and limitations of the X-ray fluorescence technique for the chalcopyrite solar cell characterization and emphasizes the advantages over the widespread electron probe microanalysis.
Fuel and Energy Abstracts
November 1999 401
Radiation resistance of high-efficiency InGaPlGaAs 99103807 tandem solar cells Takamoto, T. et al. Solar Energy Materials & Solar Cells, 1999, 58, (3), 265216. Radiation resistance of high-efficiency InGaP/GaAs tandem solar cells with a world-record efficiency of 26.9% (AMO, 28°C) has been evaluated by 1 MeV electron irradiation. Degradation in tandem cell performance has been confirmed to be mainly attributed to large degradation in the GaAs bottom cell. Similar radiation resistance with GaAs-on-Ge cells has been observed for the InGaP/GaAs tandem cell. Moreover, recovery of the tandem cell performance has been found due to minority-carrier injection under light illumination or forward bias, which causes defect annealing in InGaP top cells. The optimal design of the InGaP base layer thickness for current matching at end of life (EOL) (after irradiation with 10” electrons cm-‘) has been examined.
Rellabllity of rechargeable batteries In a photovoltsic power supply system
99103808
Urbina, A. er al. J. Power Sources, 1999, 80, (l/2), 30-38. The reliability of a rechargeable battery acting as the energy storage component in a photovoltaic power supply system was investigated. A model system was constructed that includes the solar resource, the photovoltaic power supply system, the rechargeable battery and a load. The solar resource and the system load are modelled as stochastic processes. The photovoltaic system and the rechargeable battery are modelled deterministically and an artificial neural network is incorporated into the model of the rechargeable battery to simulate damage that occurs during deep discharge cycles. The equations governing system behaviour are solved simultaneously in the Monte Carlo framework and a first passage problem is solved to assess system reliability.
Sinusoidal spectral correction for high precision outdoor module characterization
99103809
Berman, D. et al. Solar Energy Materials & Solar Cells, 1999, 58, (3), 253264. This paper presents the results of experiments which demonstrate that a sinusoidal variation in the long-term, STC-corrected, outdoor performance of PV modules is caused by seasonal spectral changes in the received sunlight. This variation may be factored out to increase the precision of outdoor studies. This result is used (a) to quantify the rate of EVA degradation observed in the Negev desert under natural l-sun conditions and (b) to identify a principal source of the summer recovery observed in modules of amorphous silicon cells.
Solar desalination based on humidification process 99iQ3810 I. Evaluating the heat and mass transfer coefficients
Nawayseh, N. K. et al. Energy Comers. Manage., 1999,40, (13), 1423-1439. For the production of fresh water from saline or sea water, solar desalination with a humidification-dehumidification process has proven to be an efficient means of utilizing solar energy. The process used in this work is a closed air cycle type, in which air is circulated in the unit by natural draft between the humidifier and condenser. In order to scale up a unit of this type, it is necessary to obtain sufficient information on the process of heat and mass transfer in the unit. The humidifier and the condenser had to be specially designed to maintain minimum pressure drop in the unit. The mass transfer coefficient in the humidifier was found to be affected mostly by the water flow rate due to its effect on the wetting area of the packing. In natural draft operation, the air circulation rate was found to increase with water flow rate, causing a further increase in the mass transfer coefficient. It was possible to predict and correlate the mass and heat transfer coefficients in the humidifiers and condensers, having different designs, in the three units constructed by the authors in Jordan and Malaysia.
Solar desalination based on humidification process II. Computer simulation
99lO3811
Nawayseh, N. K. el al. Energy Cowers. Manage., 1999,40, (13), 1441-1461. Solar desalination requires an efficient method of evaporation and condensation at relatively low temperatures. This could be suitably achieved in a humidification/dehumidification process using circulated air to enhance evaporation of the water. With proper utilization of the latent heat of condensation of water vapour, the process efficiency could be made high. In order to optimize the design of such a desalination unit, a simulation programme was constructed in which the set of non-linear equations describing the desalination unit were solved numerically. The results of the simulation were in agreement with the experimental results of two different units constructed in Jordan and Malaysia. The performance of each unit was tested when they were operated with an energy obtained either from solar or an electrical heating source. The air flow rate was found to have an insignificant effect on the productivity of desalinated water. The simulation allows the proper choice of the feed water flow rate to the unit.
99103812
Solar domestic water heating in Turkey
Akinoglu, B. G. er al. Energy, 1999, 24, (5). 363-374. The present situation of solar water heating for domestic supplies in Turkey is discussed and the results of a computer analysis for nine distinct regions are given. The analyses are carried out for four typical days of the four seasons and also on a monthly base. The results show that detailed initial work must be carried out before installing the system to determine the
Alternative
energy sources (solar energy)
optimized collector area. Such analysis can provide efficient usage of the sun’s energy as well as economical benefits in the initial investments and long-term utilization.
99103013 Solar processing of materials: opportunities and new frontiers
Flamant, G. er al. Sofur Energy, 1999, 66, (2). 117-132. The paper presents the synthesis of materials with unique properties or with a high chemical selectivity as a competitive application domain for concentrated solar energy, with respect to laser or plasma systems. To illustrate the general arguments, recent experimental data are presented in three domains: (1) surface hardening of steel, (2) oxides nanopowder processing and (3) fullerenes and nanotubes synthesis. The results obtained with 25 kW solar furnaces are evaluated in view of solar process scaling-up.
A solar-powered ice-maker with the solld adsorption pair qf activated carbon and methanol
99103814
Li, Z. F. and Sumathy, K. Int. J. Energy Res., 1999, 23, (6), 517-527. Presented here are the description and operation of a solar-powered icemaker with the solid adsorption pair of activated carbon and methanol. A domestic type of charcoal was chosen as the adsorbent and a simple flatplate collector with an exposed area of 0.92 m* was employed to produce ice of about 45 kg d-’ at an evaporator temperature of about -6°C. The above system could achieve solar refrigeration COP of about 0.1-0.12. With the description of the idealized refrigerating system, the influences of evaporating temperature, adsorbing temperature and condensing temperature on the COP were also analysed.
99io3015 Triple basin active solar still Kumar, S. and Tiwari, G. N. hr. J. Energy Res., 1999, 23, (6), 529-542. In order to solve three coupled differential equations to determine the performance of an active triple basin solar distillation system, the RungeKutta method was used. Hourly variation of various temperatures and yield have been evaluated along with overall thermal efficiency. Optimization of various parameters, namely collector and basin area and water depth with respect to daily yield, has been carried out. Numerical computations have been performed for a typical day of Delhi climate. On the basis of numeric results, it has been observed that optimization of the collector area reduces with a number of effects.
99103816 The use of corrugated booster reflectors for solar collector fields Rannelid, M. and Karlsson, B. Solar Ener~, 1999, 65, (6), 343-351. The use of booster reflectors in front of solar collectors is an established technique for increasing the irradiation onto solar collectors. By using corrugated instead of flat booster reflectors, it is possible to increase the annual irradiation onto the collector plane, thereby maximizing the annual output from the collector-reflector arrangement. The paper includes a description of a ray tracing programme which calculates the annual optical performance of a collector-booster reflector system with different Vcorrugated reflectors. Based on Swedish solar radiation data, calculations show that the use of a booster reflector with varying V-corrugations along the reflector, instead of a flat booster reflector, can increase the annual reflected direct radiation on to the collector by 10%. This is estimated to result in a 3% increase in the annual collector output. The ray-tracing calculations are compared with measurements of the reflection characteristics of single V-shaped reflector arrangements.
99103817 The 1998 World Solar Rallye: Akita, Japan Shacklock, A. et al. J. Power Sources, 1999, 80, (l/2), 199-206. Eighty-one solar/electric vehicles participated in a three day endurance race in Japan in August 1998, aiming to complete as many laps of the 31 km circuit as possible. Some of the cars used state-of-the-art motors, batteries, chassis, solar cells and tyres to produce vehicles which could travel at speeds of 70-80 km/h on about 1 kW of input power. With only 20 kg of battery, some solar cars were travelling around 450 km a day. This paper tells the story of the race and the technological developments behind the successful vehicles.
99/03818 X-ray fluorescence measurements of thin film chalcopyrite solar cells Fiyk,
M. et al.
Solar Energy Materials & Solar Cells, 1999, 58, (3), 299-
X-ray fluorescence has turned out to be a very suitable and reliable tool for the characterization of thin film chalcopyrite solar cells. Besides the composition determination in atomic percent, the total mass per unit square (mg/cm2) of the analysed elements and the film thickness can be measured accurately. Furthermore, a real multi-layer analysis allows in addition to determine the CdS, ZnO and MO thickness simultaneously with the absorber measurement. By the use of etching techniques, information about a vertical composition gradient can also be obtained. This work shows the possibilities and limitations of the X-ray fluorescence technique for the chalcopyrite solar cell characterization and emphasizes the advantages over the widespread electron probe microanalysis.
Fuel and Energy Abstracts
November 1999 401