- Email: [email protected]
00849 Diffuse solar irradiation at a location in the Balkan Peninsula
07
Alternative
energy
sources
(solar
energy)
second and third year of the cutting cycle. It is discussed that the low ECE of l-year-old shoots is related to a delay in leaf canopy development at the beginning of the growing season and lack of weed control after harvest. For the 4-years-old shoots, the low ECE, is believed to be related to the increased shoot and stool mortality caused by the self-thinning process ongoing in the willow stand. It is recommended that the harvesting interval should be based on the specific development of the stand and more attention should be paid to weed control, especially in the first growing season after harvest.Suialix
04/00845 Characterization of CulnSl thin films prepared by electrodeposition and sulfurization with photoluminescence spectroscopy Garuthara, R. et al. Solar Energy Materials and Solar Cells, 2003, 19, (3), 331-338. Potentiostatic electrodeposition and sulfurization techniques were used to prepare polycrystalline CuInSz thin films. X-ray diffraction and photoresponse measurements in a photoelectrochemical cell (PEC) revealed that photoactive polycrystalline Cub& films can be deposited on Ti substrate. Photoluminescence (PL) spectroscopy was used to investigate the prepared thin films and optically characterize them. PL spectra revealed the defect structure of the samples with an acceptor energy level at 109 meV above the valance band and a donor energy level at 71 meV below the conduction band. The CuInSz thin films prepared in this investigation are observed to be In-rich material with n-type electrical conductivity.
04100848 adsorption methanol,
Design, construction and test run of a solid solar refrigerator using activated carbon/ as adsorbentladsorbate pair
Anyanwu, E. E. and Ezekwe, C. I. Energy Conversion and Management, 2003, 44, (IQ, 287992892. The design, construction and test run of a solid adsorption solar refrigerator are presented. It used activated carbon/methanol as the adsorbent/adsorbate pair. The refrigerator has three major components: collector/generator/adsorber, condenser and evaporator. Its flat plate type collectorigeneratoriadsorber used clear plane glass sheet of effective exposed area of 1.2 mz. The steel condenser tube with a square plan view was immersed in pool of stagnant water contained in a reinforced sandcrete tank. The evaporator is a spirally coiled copper tube immersed in stagnant water. Adsorbent cooling during the adsorption process is both by natural convection of air over the collector plate and tubes and night sky radiation facilitated by removing the collector box end cover plates. Ambient temperatures during the adsorbate generation and adsorption process varied over l&5-34%. The refrigerator yielded evaporator temperatures ranging over l.O-8.5”C from water initially in the temperature range 2428°C. Accordingly, the maximum daily useful cooling produced was 266.8 kJ/ m* of collector area.
04100847
Design of a block copolymer
solar cell
Sun, S.-S. Solar Energy Materials and Solar Cells, 2003, 19, (2), 257264. A photovoltaic device based on conjugated block copolymers has been designed and preliminarily examined by the recent development of target block copolymers. The unique feature of the device includes a bridge-donor-bridge-acceptor-type of block copolymer primary structure, where donor and acceptor are conjugated polymer blocks and bridge is a non-conjugated and flexible chain, a n-orbital stacked and conjugated chain self-assembled and ordered secondary structure, and a donor/acceptor asymmetric layers sandwiched donor/acceptor columnar tertiary structure. This device is expected to improve the photovoltaic power conversion efficiency significantly in comparison to most existing organic-based donor/acceptor binary photovoltaic devices due to the reduction of exciton loss, the carrier loss, as well as the photon loss via three-dimensional space and energy level optimizations.
04lOO848 Desorption characteristics solar dehumidification/humidification systems
of desiccant bed for air conditioning
Hamed, A. M. Renewable Energy, 2003, 28, (13), 2099-2111. Theoretical and experimental investigation on the desorption characteristics of a packed porous bed is presented in this study. The granules of burned clay are applied as a desiccant carrier. Calcium chloride is used as the working desiccant. The theoretical model defines the transient gradient of air stream parameters (humidity and temperature) as well as desiccant concentration in the bed. In the experimental study, transient concentration gradient in the bed is evaluated by weight method. The bed is divided into seven separate layers. Air stream at low temperature and nearly constant inlet parameters are used for desorption purposes. Concentration gradient in the bed is found highly dependent on the mass transfer rate. For the specified operating conditions and stated assumptions, experimental measurements shows acceptable agreement with the analytical solution.
110
Fuel
and
Energy
Abstracts
March 2004
04100849 Diffuse solar irradiation Balkan Peninsula
at a location
In the
Paliatsos, A. G. et al. Renewable Energy, 2003, 28, (13), 2147-2156. This study correlates experimental values with modelled values of global (Kr) and diffuse (Kn) clearness index in Athens, Greece. The experimental values come from measurements of daily global and diffuse solar irradiation on horizontal surface, while the modelled ones are from linear regression expressions fitted to the experimental data. It is found that the correlations give excellent results for nearly all experimental periods considered (1990-2000). The study also tries to correlate Kr values with black smoke (BS) concentration. The analysis shows that there is no significant trend in KT, which would reflect an increase or decrease in light scattering by BS.
04/00850 Effect of interface parameters
recombination
on solar cell
Saad, M. and Kassis, A. Solar Energy Materials and Solar Cells, 2003, 79, (4), 507-517. A model is presented for p-n hetero-junction solar cells in which interface recombination is the dominant diode current transport mechanism. The model explains the large diode ideality factor (n > 2) and the increased saturation current density in terms of increased density of interface states n,,. Furthermore, the model allows us to explain the non-translation between illuminated and dark J-V characteristics. The explanation is based on the assumption that, for high interface state density values, both the depletion layer width and the diffusion voltage in the p- and n-side of the junction are functions of ni,. The interface recombination leads to lower values of the opencircuit voltage, short-circuit current density, and till factor. These results are illustrated by numerical calculations of solar cell parameters and compared with experimental data achieved for ZnO/CdS/CuGaSez single-crystal solar cells.
04/00851 conducting
Electrochemical corrosion of SnO*:F transparent layers in thin-film photovoltalc modules
Osterwald, C. R. et al. Solar Energy Materials and Solar Cells, 2003, 79, (1) 21-33. This paper reports on a degradation mechanism in thin-film photovoltaic (PV) modules activated by damp heat and voltages similar in magnitude to those generated by PV modules in power generation systems. This mechanism, which appears to be an electrochemical process involving the soda-lime glass superstrate with its conductive SnOa:F layer, can be greatly accelerated by subjecting modules to elevated temperatures and humidity, both of which increase the leakage currents between the frame and the active PV layers. Water vapour can affect the module damage in two ways: (1) by enhancing leakage currents, and (2) by entering through the module edges, it appears to promote the chemical reaction responsible for the SnOa corrosion. Damage has been found to occur in both a-Si and CdTe modules.
04100852 Experimental and theoretical evaluation performance of a tar solar water heater
of the
Ammari, H. D. and Nimir, Y. L. Energy Conversion and Management, 2003, 44, (19) 3037-3055. The paper presents an experimental and theoretical evaluation of the performance of a tar solar water heater and comparison with that of a conventional type collector. The performance of both collectors is assessed under the same conditions. Both of the collectors have the same surface area and are glazed. The conventional type has the water tubes welded to the absorber plate, whereas in the tar type, the tar acts as an absorber plate that covers the water tubes. The theoretical model for each collector type, with the transient effects taken into account, is based on a control volume and a time base in the related energy equations. By considering a small element of the collector in each case, three partial differential equations were developed for each collector and were solved numerically by the Runge-Kutta method of the fifth order. A good agreement was achieved between the numerical and experimental results for both the conventional and tar collectors, indicating the feasibility of employing the theoretical model in the design of flat plate solar collectors. The results also showed that the conventional collector is more efficient than the tar type during most of the daylight, but the tar collector had the added advantage of better conservation of energy in late afternoon and evening.
04/00853 Field experience on solar electric and their potential in Palestine
power systems
Mahmoud, M. M. and Ibrik, I. H. Renewable and Sustainable Energy Reviews, 2003, 7, (6), 531-543. Palestine has a large number of rural small villages far from the national electric grids. Electrical loads in such villages are mostly small and can be covered by means of photovoltaic (PV) generators, which are economically more feasible than extending the electric grid or using diesel electric generators. Since PV has been rarely used in Palestine, this paper is devoted to investigating the potential of PV applications in
Alternative
energy
sources
(solar
energy)
second and third year of the cutting cycle. It is discussed that the low ECE of l-year-old shoots is related to a delay in leaf canopy development at the beginning of the growing season and lack of weed control after harvest. For the 4-years-old shoots, the low ECE, is believed to be related to the increased shoot and stool mortality caused by the self-thinning process ongoing in the willow stand. It is recommended that the harvesting interval should be based on the specific development of the stand and more attention should be paid to weed control, especially in the first growing season after harvest.Suialix
04/00845 Characterization of CulnSl thin films prepared by electrodeposition and sulfurization with photoluminescence spectroscopy Garuthara, R. et al. Solar Energy Materials and Solar Cells, 2003, 19, (3), 331-338. Potentiostatic electrodeposition and sulfurization techniques were used to prepare polycrystalline CuInSz thin films. X-ray diffraction and photoresponse measurements in a photoelectrochemical cell (PEC) revealed that photoactive polycrystalline Cub& films can be deposited on Ti substrate. Photoluminescence (PL) spectroscopy was used to investigate the prepared thin films and optically characterize them. PL spectra revealed the defect structure of the samples with an acceptor energy level at 109 meV above the valance band and a donor energy level at 71 meV below the conduction band. The CuInSz thin films prepared in this investigation are observed to be In-rich material with n-type electrical conductivity.
04100848 adsorption methanol,
Design, construction and test run of a solid solar refrigerator using activated carbon/ as adsorbentladsorbate pair
Anyanwu, E. E. and Ezekwe, C. I. Energy Conversion and Management, 2003, 44, (IQ, 287992892. The design, construction and test run of a solid adsorption solar refrigerator are presented. It used activated carbon/methanol as the adsorbent/adsorbate pair. The refrigerator has three major components: collector/generator/adsorber, condenser and evaporator. Its flat plate type collectorigeneratoriadsorber used clear plane glass sheet of effective exposed area of 1.2 mz. The steel condenser tube with a square plan view was immersed in pool of stagnant water contained in a reinforced sandcrete tank. The evaporator is a spirally coiled copper tube immersed in stagnant water. Adsorbent cooling during the adsorption process is both by natural convection of air over the collector plate and tubes and night sky radiation facilitated by removing the collector box end cover plates. Ambient temperatures during the adsorbate generation and adsorption process varied over l&5-34%. The refrigerator yielded evaporator temperatures ranging over l.O-8.5”C from water initially in the temperature range 2428°C. Accordingly, the maximum daily useful cooling produced was 266.8 kJ/ m* of collector area.
04100847
Design of a block copolymer
solar cell
Sun, S.-S. Solar Energy Materials and Solar Cells, 2003, 19, (2), 257264. A photovoltaic device based on conjugated block copolymers has been designed and preliminarily examined by the recent development of target block copolymers. The unique feature of the device includes a bridge-donor-bridge-acceptor-type of block copolymer primary structure, where donor and acceptor are conjugated polymer blocks and bridge is a non-conjugated and flexible chain, a n-orbital stacked and conjugated chain self-assembled and ordered secondary structure, and a donor/acceptor asymmetric layers sandwiched donor/acceptor columnar tertiary structure. This device is expected to improve the photovoltaic power conversion efficiency significantly in comparison to most existing organic-based donor/acceptor binary photovoltaic devices due to the reduction of exciton loss, the carrier loss, as well as the photon loss via three-dimensional space and energy level optimizations.
04lOO848 Desorption characteristics solar dehumidification/humidification systems
of desiccant bed for air conditioning
Hamed, A. M. Renewable Energy, 2003, 28, (13), 2099-2111. Theoretical and experimental investigation on the desorption characteristics of a packed porous bed is presented in this study. The granules of burned clay are applied as a desiccant carrier. Calcium chloride is used as the working desiccant. The theoretical model defines the transient gradient of air stream parameters (humidity and temperature) as well as desiccant concentration in the bed. In the experimental study, transient concentration gradient in the bed is evaluated by weight method. The bed is divided into seven separate layers. Air stream at low temperature and nearly constant inlet parameters are used for desorption purposes. Concentration gradient in the bed is found highly dependent on the mass transfer rate. For the specified operating conditions and stated assumptions, experimental measurements shows acceptable agreement with the analytical solution.
110
Fuel
and
Energy
Abstracts
March 2004
04100849 Diffuse solar irradiation Balkan Peninsula
at a location
In the
Paliatsos, A. G. et al. Renewable Energy, 2003, 28, (13), 2147-2156. This study correlates experimental values with modelled values of global (Kr) and diffuse (Kn) clearness index in Athens, Greece. The experimental values come from measurements of daily global and diffuse solar irradiation on horizontal surface, while the modelled ones are from linear regression expressions fitted to the experimental data. It is found that the correlations give excellent results for nearly all experimental periods considered (1990-2000). The study also tries to correlate Kr values with black smoke (BS) concentration. The analysis shows that there is no significant trend in KT, which would reflect an increase or decrease in light scattering by BS.
04/00850 Effect of interface parameters
recombination
on solar cell
Saad, M. and Kassis, A. Solar Energy Materials and Solar Cells, 2003, 79, (4), 507-517. A model is presented for p-n hetero-junction solar cells in which interface recombination is the dominant diode current transport mechanism. The model explains the large diode ideality factor (n > 2) and the increased saturation current density in terms of increased density of interface states n,,. Furthermore, the model allows us to explain the non-translation between illuminated and dark J-V characteristics. The explanation is based on the assumption that, for high interface state density values, both the depletion layer width and the diffusion voltage in the p- and n-side of the junction are functions of ni,. The interface recombination leads to lower values of the opencircuit voltage, short-circuit current density, and till factor. These results are illustrated by numerical calculations of solar cell parameters and compared with experimental data achieved for ZnO/CdS/CuGaSez single-crystal solar cells.
04/00851 conducting
Electrochemical corrosion of SnO*:F transparent layers in thin-film photovoltalc modules
Osterwald, C. R. et al. Solar Energy Materials and Solar Cells, 2003, 79, (1) 21-33. This paper reports on a degradation mechanism in thin-film photovoltaic (PV) modules activated by damp heat and voltages similar in magnitude to those generated by PV modules in power generation systems. This mechanism, which appears to be an electrochemical process involving the soda-lime glass superstrate with its conductive SnOa:F layer, can be greatly accelerated by subjecting modules to elevated temperatures and humidity, both of which increase the leakage currents between the frame and the active PV layers. Water vapour can affect the module damage in two ways: (1) by enhancing leakage currents, and (2) by entering through the module edges, it appears to promote the chemical reaction responsible for the SnOa corrosion. Damage has been found to occur in both a-Si and CdTe modules.
04100852 Experimental and theoretical evaluation performance of a tar solar water heater
of the
Ammari, H. D. and Nimir, Y. L. Energy Conversion and Management, 2003, 44, (19) 3037-3055. The paper presents an experimental and theoretical evaluation of the performance of a tar solar water heater and comparison with that of a conventional type collector. The performance of both collectors is assessed under the same conditions. Both of the collectors have the same surface area and are glazed. The conventional type has the water tubes welded to the absorber plate, whereas in the tar type, the tar acts as an absorber plate that covers the water tubes. The theoretical model for each collector type, with the transient effects taken into account, is based on a control volume and a time base in the related energy equations. By considering a small element of the collector in each case, three partial differential equations were developed for each collector and were solved numerically by the Runge-Kutta method of the fifth order. A good agreement was achieved between the numerical and experimental results for both the conventional and tar collectors, indicating the feasibility of employing the theoretical model in the design of flat plate solar collectors. The results also showed that the conventional collector is more efficient than the tar type during most of the daylight, but the tar collector had the added advantage of better conservation of energy in late afternoon and evening.
04/00853 Field experience on solar electric and their potential in Palestine
power systems
Mahmoud, M. M. and Ibrik, I. H. Renewable and Sustainable Energy Reviews, 2003, 7, (6), 531-543. Palestine has a large number of rural small villages far from the national electric grids. Electrical loads in such villages are mostly small and can be covered by means of photovoltaic (PV) generators, which are economically more feasible than extending the electric grid or using diesel electric generators. Since PV has been rarely used in Palestine, this paper is devoted to investigating the potential of PV applications in