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00549 Effects of mismatch losses in photovoltaic arrays
07
96/00539 CulnSr, based solar cell structures by CVTG Sebastian, P. J. er al., Applied Energy, 1995, 52, (2), 199-207. Describes chemical vapor transport by gas (CVTG) which is a new method to grow semiconductor thin films, transparent conductors and hence solar cell structures economically.
96/00540 A dayllt school In North Carolina Miller Thayer, B. Solar Today, Nov.-Dec. 1995, 9, (6), 36-39. Describes how Raleigh architects use daylighting design to reduce costs and improve the learning and working environment in schools in North Carolina, USA.
Doctor PV. lnverters - Local lncompatlbllity and related Issues
96lOQ541
McCray, M. Solar Today, Nov.-Dec. 1995, 9, (6), 40-43. The author examines aspects of inverters - loads that may not start or operate properly on inverter power and other problems caused by inverter output.
96100642
Economic analysis of flat plate collectors of solar
energy Ozsabuncuoglu, I. H. Energy Policy, Sep. 1995, 23, (9), 755-763. Althoueh solar enerev ootential in Turkev is far more than its total annual energy-consumptio;: ‘because of techiical, economic and efficiency problems it cannot be harnessed to its fullest extent. Solar energy collecting systems have an initial cost two or five times higher than aiiernatives using electricity, LPG, fuel or other solid energy sources. However, their annual reoair and maintenance costs are much lower than alternatives due to high &ergy prices. Solar systems with inflated annual costs have a minimum present value of US$867.19. Solar energy systems can be recommended f& the countries that want a dependabie and environmentally sound energy source. However, investment in R&D activities is necessary to reduce total cost of the system through improved efficiency and better production technology.
Effect of baffle plate on the performance of a trlangular built-In-storage solar water heater
96lOO543
Kaushik, S. C. et al., Energy Convers. Mgmt., May 1995, 36, (5), 337-342. The triangular design of a solar water heater not only enhances the overall gain to the system but also improves the natural convection between the absorbing plate and the water, leading to better performance of the system. A night insulation cover is used at the top surface of the heater to reduce the losses from the system during the off-sunshine hours. Another way to reduce the losses from the system is by using an insulating baffle plate in the tank. This plate divides the tank water into two portions, the water above this plate is known as the upper column and below is known as the lower column. The proposed system is studied by varying the vent area, the water mass in the two columns and under a constant flow rate for different durations.
Effect of hot water load temperature on the erformance of a thermosyphon solar water heater with auxllPary electric heater
96100546
;;;y;;;
A. M. and Ecevit, A.
Effect of geometrical and thermophyslcal characteristics of bed materials on the enhancement of thermal performance of packed bed solar air heaters
Ahmad, A. et al., Energy Convers. Mgmf., Dec. 1995, 36, (12). 1185-1195. In this experimental investigation, a packed bed solar air heater has been designed, fabricated and tested under the local weather conditions of Roorkee, In&a. Data were obtained from May to June 1992. Tests were conducted to cover a wide range of influencing parameters, including the geometrical and thermophysical characteristics of absorber matrices, mass flow rates and input solar energy fluxes under actual outdoor conditions. The effects of these parameters on the thermal performance have been investigated, and the results have been compared with those of flat plat (plane) collectors.
The effect of heat recovery on the performance of a glazed solar collector/regenerator
96lQQ545
Yang, R. and Wang, P. L. Solar Energy, Jan. 1995, 54, (l), 19-24. The paper describes an experimental study for the effect of a heat exchanger on the performance of a 2 m X 9 m glazed solar collector/regenerator for an open-cycle absorption solar cooling system operated under humid climates. The working fluid is aqueous lithium chloride solution and the refrigerant is water. Heat is recovered from the outlet solution to preheat the inlet solution by a heat exchanger. The results show a significant performance increase of 25%. Data are correlated by dimensionless
Energy Convers. Mgmr., May 1995,36,
(5),
A thennosyphon solar water heating system with an in-tank auxiliary electric heater has been simulated for different hot water load temoeratures using the TRNSYS simulation program. The results of the simuladon show that the annual efficiency and solar fraction are functions of the hot water load temperatures. The effect of load temperature on the solar fraction is found to be very large when the daily load volume (the volume of hot water delivered to load) to collector area ratio is laree. The influence of storage tank volume to iollector area ratio on the efficgncy of the collector is observed only when this ratio is less than or equal to 40 1 m2 for all collector areas and load temperatures studied.
Effect of hot-water consumption on temperature dlstrlbutlon In a horlzontal solar water storage tank
96100547
Helwa, N. H. et al.,
Applied Energy,
1995, 52, (2), 185-197.
The experimental investigation assesses the behaviour of a solar water heater provided with a liquid heat exchanger in a horizontal storage tank. The factors that affect the stratification inside the storage tank are considered. The performance of the system is studied in the light of the daily consumption of hot water of an Egyptian family. The results obtained show that in the places where it is necessary to use a horizontal tank it must be supplied with an auxiliary electric heater to meet the required load at the required temperature, especially in winter.
Effect of water turbldlty on thermal performance of a salt-gradlent solar pond
96100546
Wang, J. and Seyed-Yagoobi, 301-308.
J.
Solar
Energy,
May 1995, 54, (5),
The effect of water turbidity on the thermal performance of a salt-gradient solar pond is studied using a one-dimensional theoretical model. The theoretical model uses an empirical correlation that includes the effect of water turbiditv on solar radiation nenetration in water. The correlation is based on a &form turbidity distiibution in water, however, the correlation is extended to include a non-uniform turbidity distribution with respect to depth of water. The results indicate that water clarity plays a significant role on thermal performance for salt gradient solar ponds.
96100549
Chamberlin,
Effects of mismatch losses In photovoltalc arrays C. E. et al.,
Solar Energy, Mar. 1995, 54, (3), 165-171.
Experimental and modelling results on the effects of mismatch losses in photovoltaic arrays are presented. Field tests conducted on each of the 192 modules are used to debcribe the variation in the properties of production run photovoltaic modules.
96100550
Reddy, B. S. 96100544
energy sources (solar energy)
Alternative
Electrical vs solar water heater: A case study Energy Convers. Mgmt., Nov. 1995, 36, (II),
1097-1106.
In the present day environment, high quality energy carriers (in terms of thermodynamics), such as electricity, are being used inefficiently for low quality tasks, such as water heating, which could be done just as well by a low quality energy carrier or source. In other words, we employ every resource in the production of the highest quality of energy and then waste it by going downhill to low quality tasks, which means the wasting of capital investment. However, in the case of solar energy, it is delivered to the earth at a rather low temperature and is, therefore, quite suitable for tasks such as water heating. Also, such energy systems provide economic and physical diversity without any chemical combustion which causes environmental pollution.
96100551
Energy losses In photovoltalc systems
Anis, W. R. and Abdul-Sadek 1995, 36, (II), 1107-1113.
Nour, M.
Energy Cowers.
Mgmt., Nov.
The maximum power generated by photovoltaic (PV) arrays is not fully used. There are many reasons leading to energy loss. A main reason of energy loss during the summer is the system design which necessitates PV array oversizing to su ply the load during the winter season when solar energy is limited. Ot g er reasons that cause energy loss are mismatch between the array and the load or battery, energy loss in batteries and loss due to PV array disconnect. The array disconnect loss takes place during the summer season when the storaee batterv is fullv chareed. To avoid the disconnect loss, a novel battery vofiage regilator &at all;ws supplying the load directly from the array is used, when the battery is fully charged. In this work, energy losses have been analysed and divided into fundamental (unavoidable) and non- fundamental losses.
Fuel and Energy Abstracts January 1996
33
96/00539 CulnSr, based solar cell structures by CVTG Sebastian, P. J. er al., Applied Energy, 1995, 52, (2), 199-207. Describes chemical vapor transport by gas (CVTG) which is a new method to grow semiconductor thin films, transparent conductors and hence solar cell structures economically.
96/00540 A dayllt school In North Carolina Miller Thayer, B. Solar Today, Nov.-Dec. 1995, 9, (6), 36-39. Describes how Raleigh architects use daylighting design to reduce costs and improve the learning and working environment in schools in North Carolina, USA.
Doctor PV. lnverters - Local lncompatlbllity and related Issues
96lOQ541
McCray, M. Solar Today, Nov.-Dec. 1995, 9, (6), 40-43. The author examines aspects of inverters - loads that may not start or operate properly on inverter power and other problems caused by inverter output.
96100642
Economic analysis of flat plate collectors of solar
energy Ozsabuncuoglu, I. H. Energy Policy, Sep. 1995, 23, (9), 755-763. Althoueh solar enerev ootential in Turkev is far more than its total annual energy-consumptio;: ‘because of techiical, economic and efficiency problems it cannot be harnessed to its fullest extent. Solar energy collecting systems have an initial cost two or five times higher than aiiernatives using electricity, LPG, fuel or other solid energy sources. However, their annual reoair and maintenance costs are much lower than alternatives due to high &ergy prices. Solar systems with inflated annual costs have a minimum present value of US$867.19. Solar energy systems can be recommended f& the countries that want a dependabie and environmentally sound energy source. However, investment in R&D activities is necessary to reduce total cost of the system through improved efficiency and better production technology.
Effect of baffle plate on the performance of a trlangular built-In-storage solar water heater
96lOO543
Kaushik, S. C. et al., Energy Convers. Mgmt., May 1995, 36, (5), 337-342. The triangular design of a solar water heater not only enhances the overall gain to the system but also improves the natural convection between the absorbing plate and the water, leading to better performance of the system. A night insulation cover is used at the top surface of the heater to reduce the losses from the system during the off-sunshine hours. Another way to reduce the losses from the system is by using an insulating baffle plate in the tank. This plate divides the tank water into two portions, the water above this plate is known as the upper column and below is known as the lower column. The proposed system is studied by varying the vent area, the water mass in the two columns and under a constant flow rate for different durations.
Effect of hot water load temperature on the erformance of a thermosyphon solar water heater with auxllPary electric heater
96100546
;;;y;;;
A. M. and Ecevit, A.
Effect of geometrical and thermophyslcal characteristics of bed materials on the enhancement of thermal performance of packed bed solar air heaters
Ahmad, A. et al., Energy Convers. Mgmf., Dec. 1995, 36, (12). 1185-1195. In this experimental investigation, a packed bed solar air heater has been designed, fabricated and tested under the local weather conditions of Roorkee, In&a. Data were obtained from May to June 1992. Tests were conducted to cover a wide range of influencing parameters, including the geometrical and thermophysical characteristics of absorber matrices, mass flow rates and input solar energy fluxes under actual outdoor conditions. The effects of these parameters on the thermal performance have been investigated, and the results have been compared with those of flat plat (plane) collectors.
The effect of heat recovery on the performance of a glazed solar collector/regenerator
96lQQ545
Yang, R. and Wang, P. L. Solar Energy, Jan. 1995, 54, (l), 19-24. The paper describes an experimental study for the effect of a heat exchanger on the performance of a 2 m X 9 m glazed solar collector/regenerator for an open-cycle absorption solar cooling system operated under humid climates. The working fluid is aqueous lithium chloride solution and the refrigerant is water. Heat is recovered from the outlet solution to preheat the inlet solution by a heat exchanger. The results show a significant performance increase of 25%. Data are correlated by dimensionless
Energy Convers. Mgmr., May 1995,36,
(5),
A thennosyphon solar water heating system with an in-tank auxiliary electric heater has been simulated for different hot water load temoeratures using the TRNSYS simulation program. The results of the simuladon show that the annual efficiency and solar fraction are functions of the hot water load temperatures. The effect of load temperature on the solar fraction is found to be very large when the daily load volume (the volume of hot water delivered to load) to collector area ratio is laree. The influence of storage tank volume to iollector area ratio on the efficgncy of the collector is observed only when this ratio is less than or equal to 40 1 m2 for all collector areas and load temperatures studied.
Effect of hot-water consumption on temperature dlstrlbutlon In a horlzontal solar water storage tank
96100547
Helwa, N. H. et al.,
Applied Energy,
1995, 52, (2), 185-197.
The experimental investigation assesses the behaviour of a solar water heater provided with a liquid heat exchanger in a horizontal storage tank. The factors that affect the stratification inside the storage tank are considered. The performance of the system is studied in the light of the daily consumption of hot water of an Egyptian family. The results obtained show that in the places where it is necessary to use a horizontal tank it must be supplied with an auxiliary electric heater to meet the required load at the required temperature, especially in winter.
Effect of water turbldlty on thermal performance of a salt-gradlent solar pond
96100546
Wang, J. and Seyed-Yagoobi, 301-308.
J.
Solar
Energy,
May 1995, 54, (5),
The effect of water turbidity on the thermal performance of a salt-gradient solar pond is studied using a one-dimensional theoretical model. The theoretical model uses an empirical correlation that includes the effect of water turbiditv on solar radiation nenetration in water. The correlation is based on a &form turbidity distiibution in water, however, the correlation is extended to include a non-uniform turbidity distribution with respect to depth of water. The results indicate that water clarity plays a significant role on thermal performance for salt gradient solar ponds.
96100549
Chamberlin,
Effects of mismatch losses In photovoltalc arrays C. E. et al.,
Solar Energy, Mar. 1995, 54, (3), 165-171.
Experimental and modelling results on the effects of mismatch losses in photovoltaic arrays are presented. Field tests conducted on each of the 192 modules are used to debcribe the variation in the properties of production run photovoltaic modules.
96100550
Reddy, B. S. 96100544
energy sources (solar energy)
Alternative
Electrical vs solar water heater: A case study Energy Convers. Mgmt., Nov. 1995, 36, (II),
1097-1106.
In the present day environment, high quality energy carriers (in terms of thermodynamics), such as electricity, are being used inefficiently for low quality tasks, such as water heating, which could be done just as well by a low quality energy carrier or source. In other words, we employ every resource in the production of the highest quality of energy and then waste it by going downhill to low quality tasks, which means the wasting of capital investment. However, in the case of solar energy, it is delivered to the earth at a rather low temperature and is, therefore, quite suitable for tasks such as water heating. Also, such energy systems provide economic and physical diversity without any chemical combustion which causes environmental pollution.
96100551
Energy losses In photovoltalc systems
Anis, W. R. and Abdul-Sadek 1995, 36, (II), 1107-1113.
Nour, M.
Energy Cowers.
Mgmt., Nov.
The maximum power generated by photovoltaic (PV) arrays is not fully used. There are many reasons leading to energy loss. A main reason of energy loss during the summer is the system design which necessitates PV array oversizing to su ply the load during the winter season when solar energy is limited. Ot g er reasons that cause energy loss are mismatch between the array and the load or battery, energy loss in batteries and loss due to PV array disconnect. The array disconnect loss takes place during the summer season when the storaee batterv is fullv chareed. To avoid the disconnect loss, a novel battery vofiage regilator &at all;ws supplying the load directly from the array is used, when the battery is fully charged. In this work, energy losses have been analysed and divided into fundamental (unavoidable) and non- fundamental losses.
Fuel and Energy Abstracts January 1996
33