- Email: [email protected]
00231 A novel underground solar thermal heat storage unit cum heat exchanger for non air-conditioned buildings
07 Alternative energy sources (solar energy) described. The study illustrates the importance of a multidisciplinary approach to gain an understanding of the behaviour of geothermal systems under production.
05/00229 Spatial decision analysis of geothermal resource sites in the Qualibou Caldera, Saint Lucia, Lesser Antilles Coles, D. et al. Geothermics, 2004, 33, (3), 277 308. Over several decades, the Saint Lucian Government and several international organizations have assessed the geothermal resource within the Qualibou Caldera, Saint Lucia. Over that period of time, nine exploratory wells were drilled to find an ideal location for a geothermal electric plant; to date, a suitable location has not been discovered. Herein, a spatial subjective probabilistic decision analysis has been developed and applied to historic and contemporaneous datasets to identify a new set of exploratory locations. This simple decision methodology might, for example, benefit applied geoscientists as well as nations seeking a modicum of independence from foreign consultation.
Solar energy
solar and ultraviolet radiation, common glass borosilicate, quartz assay tubes, and no solid catalysts. The colour of blue dye and a mixture of blue and red dyes were almost completely removed after 3 h, either by solar or ultraviolet radiation. The best results of colour removal (93%) for the red and yellow dyestuffs were obtained only after 6 h, using quartz tubes, hydrogen peroxide and ultraviolet radiation. Using nonparametrical statistical tests (X2), the treatment showed significant differences among the processes investigated (P < 0.01).
05/00233 Calculation on an hourly basis of solar diffuse irradiations from global data for horizontal surfaces in Ajaccio Notton, G. el al. Energy Conversion and Management, 2004, 45, (1819), 2849-2866. Hourly global irradiations on tilted planes are required in various engineering calculations for solar systems. In a lot of sites, at best, only global irradiations on horizontal planes are available. To calculate the global irradiation on inclined surfaces from horizontal global irradiation, the fist step consists in determining the horizontal diffuse component. Thus, the variation of the diffuse component with global irradiation on an hourly basis was considered. Several correlations between hourly values of diffuse and global irradiations are presented, validated and compared using solar data collected on the French Mediterranean site of Ajaccio.
05/00230 A commercial approach to solar power distribution in India
05/00234 Calibration corrections of solar tower flux density measurements
Bhattacharjee, C. R. International Journal of Global Energy Issues, 2003, 20, (1), 115-118. In India, approximately 5,000 of 79,000 unelectrified villages, either unapproachable from the grid line or subject to uneconomic viability, are awaiting electricity through SPV power as the only suitable technological option. SPV power, which is expensive in capital cost, although affordable in tariff, is on successful trial through a novel scheme that is subsidy-free. Limited scale applications, with ten plants of 20-50 kW capacities in successful operation, are situated at Sagardweep, an island in southern West Bengal in India. The objective is to improve the quality of living standards there. The cost of energy per kWh is approximately $0.16. No doubt this is high, considering the grid tariff is less than 50%, but it is acceptable to people in the context of the scarcity, high price and inconvenience associated with kerosene or diesel fuel as the only alternative energy resources.
Ulmer, S. et al. Energy, 2004, 29, (5 6), 925-933. The PSA flux density measuring system PROHERMES measures the concentrated solar radiation in the entrance aperture of solar tower receivers with a white rotating bar as target and a CCD-camera taking images. The calibration is done with commercial flux gauges placed in the measurement plane. To improve the calibration of the system and to reveal systematic errors, measurements are performed with two different types of commercial flux gauges (Thermogage sensors with and without quartz window) and a large custom-made calorimeter used as reference. The comparison shows that the sensors without quartz window measure about 5-8% higher and the sensors with quartz window about 100% higher. This error is explained with the differences in the spectral composition of the radiation and different angles of incidence between the manufacturer calibration and the solar measurements and corrections are proposed. Spectral changes of the sunlight during the day and year can affect the measurements by more than 10%. By selecting a correction filter adapted to the camera sensitivity, this influence can be reduced to less than 2.5%. Due to the reflective properties of the target coating, changes in angle of incidence can affect the measurements. In standard solar field conditions, this error is less than 0.5%, but for special conditions a correction of the systematic error of up to 8% is proposed.
05/00231 A novel underground solar thermal heat storage unit cum heat exchanger for non air-conditioned buildings Kumar, R. and Kaushik, S.C. International Journal ~/" Global Energy Issues, 2003, 20, (2), 208-222. A novel passive space conditioning configuration is presented integrating a Solar Collector System, Underground Storage Tank and Novel Heat Exchanger. This Underground Solar Thermal Heat Exchanger (USTHE) provided improved sensible heating/cooling of air by employing a Novel Heat Exchanger (NHX). The dynamic performance of the storage tank in USTHE is modelled using the Finite Difference method accounting thermal stratification of water into three nodes (three isothermal segments). Analysis of NHX incorporated thermal heat transfer between water in the load loop of a storage tank and cross flowing air in the heat exchanger. Savings were incorporated in the building code in Matlab using a one-dimensional heat conduction equation. A wide range of experimental data was collected for validating the modelling results. Simulations were performed for several parameters viz. solar collector area (Ac), sizing of the storage tank, mass flow rate of water in collector loop (Wc) and load loop (WI) in daytime and night operations and air flow rate in novel heat exchanger. The effect of these simulations was predicted in terms of useful energy supplied by USTHE, thermal energy retaining period, collector temperature and averaged stratified temperature. Performance of USTHE is evaluated to give maximum heating potential. Effect of averaged isothermal segment temperature, stratification level and day and night flow rate combinations on heating potential is studied in great depth. USTHE supplied a peak heating potential of 5 kWh with a collector water flow rate of 252 kg/h and load water flow rate of 60 kg/h and obtained a maximum averaged temperature of stratified tank of 37.1°C. Building heating load savings were 6.98 kWh during daytime and 2.92 kWh at night on 11 December 2001. Dry bulb temperature of air increased by 10.2°C (peak value at 3.00 p.m.) on 1 January 2002 while water temperature decreased by 4.2°C.
05/00232 Bleaching and photodegradation of textile dyes by H202 and solar or ultraviolet radiation Costa, F. A. P. et al. Solar Energy, 2004, 77, (1), 29 35. The photo-oxidation of textile dyes Yellow Procion H-4R, Bright Blue Remazol (blue reagent-19), Red Procion H-E7B, and the mixture of the two last dyes were investigated. The efficiency of photo-oxidation was compared using hydrogen peroxide (30%) as a bleaching reagent,
32
Fuel and Energy Abstracts January 2005
05/00235 Characteristics of nanocrystalline CdS films fabricated by sonochemical, microwave and solution growth methods for solar cell applications Singh, V. P. Solar Energy Materials and Solar Cells, 2004, 81, (3), 293 303. Nanocrystalline CdS was synthesized by sonochemical and microwave methods. Characterization of nano-CdS was carried out by optical absorption, X-ray diffraction, TEM, SEM and EDX. A hyperbolic band model was used to calculate a shift in energy over that of the band gap of bulk CdS. Colloidal films comprising of nanocrystalline CdS were fabricated by the dip coating method. A comparison of optical absorption of CdS films on indium tin oxide (ITO)/glass by sonochemical and microwave methods was made with solution grown CdS films on ITO/glass. A blue shift in energy level at the nanoscale is demonstrated by optical absorption, and X-ray diffraction of nano-CdS shows a cubic structure. Electron microscopy studies with an FE-SEM and TEM show a particle size of 15 nm and diffraction patterns show a crystalline nature. Overall reduction in optical absorption due to blue shift is expected to result in higher performance, especially in shortcircuit currents in CdS/CdTe solar cells.
05•00236 Demand side management for remote area power supply systems incorporating solar irradiance model A1-Alawi, A. and Islam, S. M. Renewable Energy, 2004, 29, (13), 20272036. This paper presents a technique for generating the daily electricity load profile for remote areas in the Middle East from first principles, using diversified demand. The generated load profile includes the energy required to run a small desalination unit to provide the necessary freshwater. Demand side management (DSM) is used in this study to smooth out the daily peaks and fill valleys in the load curve to make the most efficient use of energy resources. Finally, the load profile is compared with real data for six houses collected from Safri area in the Sultanate of Oman. These data may be used as the basis to obtain load profiles of other remote areas of the Middle East since the weather and
05/00229 Spatial decision analysis of geothermal resource sites in the Qualibou Caldera, Saint Lucia, Lesser Antilles Coles, D. et al. Geothermics, 2004, 33, (3), 277 308. Over several decades, the Saint Lucian Government and several international organizations have assessed the geothermal resource within the Qualibou Caldera, Saint Lucia. Over that period of time, nine exploratory wells were drilled to find an ideal location for a geothermal electric plant; to date, a suitable location has not been discovered. Herein, a spatial subjective probabilistic decision analysis has been developed and applied to historic and contemporaneous datasets to identify a new set of exploratory locations. This simple decision methodology might, for example, benefit applied geoscientists as well as nations seeking a modicum of independence from foreign consultation.
Solar energy
solar and ultraviolet radiation, common glass borosilicate, quartz assay tubes, and no solid catalysts. The colour of blue dye and a mixture of blue and red dyes were almost completely removed after 3 h, either by solar or ultraviolet radiation. The best results of colour removal (93%) for the red and yellow dyestuffs were obtained only after 6 h, using quartz tubes, hydrogen peroxide and ultraviolet radiation. Using nonparametrical statistical tests (X2), the treatment showed significant differences among the processes investigated (P < 0.01).
05/00233 Calculation on an hourly basis of solar diffuse irradiations from global data for horizontal surfaces in Ajaccio Notton, G. el al. Energy Conversion and Management, 2004, 45, (1819), 2849-2866. Hourly global irradiations on tilted planes are required in various engineering calculations for solar systems. In a lot of sites, at best, only global irradiations on horizontal planes are available. To calculate the global irradiation on inclined surfaces from horizontal global irradiation, the fist step consists in determining the horizontal diffuse component. Thus, the variation of the diffuse component with global irradiation on an hourly basis was considered. Several correlations between hourly values of diffuse and global irradiations are presented, validated and compared using solar data collected on the French Mediterranean site of Ajaccio.
05/00230 A commercial approach to solar power distribution in India
05/00234 Calibration corrections of solar tower flux density measurements
Bhattacharjee, C. R. International Journal of Global Energy Issues, 2003, 20, (1), 115-118. In India, approximately 5,000 of 79,000 unelectrified villages, either unapproachable from the grid line or subject to uneconomic viability, are awaiting electricity through SPV power as the only suitable technological option. SPV power, which is expensive in capital cost, although affordable in tariff, is on successful trial through a novel scheme that is subsidy-free. Limited scale applications, with ten plants of 20-50 kW capacities in successful operation, are situated at Sagardweep, an island in southern West Bengal in India. The objective is to improve the quality of living standards there. The cost of energy per kWh is approximately $0.16. No doubt this is high, considering the grid tariff is less than 50%, but it is acceptable to people in the context of the scarcity, high price and inconvenience associated with kerosene or diesel fuel as the only alternative energy resources.
Ulmer, S. et al. Energy, 2004, 29, (5 6), 925-933. The PSA flux density measuring system PROHERMES measures the concentrated solar radiation in the entrance aperture of solar tower receivers with a white rotating bar as target and a CCD-camera taking images. The calibration is done with commercial flux gauges placed in the measurement plane. To improve the calibration of the system and to reveal systematic errors, measurements are performed with two different types of commercial flux gauges (Thermogage sensors with and without quartz window) and a large custom-made calorimeter used as reference. The comparison shows that the sensors without quartz window measure about 5-8% higher and the sensors with quartz window about 100% higher. This error is explained with the differences in the spectral composition of the radiation and different angles of incidence between the manufacturer calibration and the solar measurements and corrections are proposed. Spectral changes of the sunlight during the day and year can affect the measurements by more than 10%. By selecting a correction filter adapted to the camera sensitivity, this influence can be reduced to less than 2.5%. Due to the reflective properties of the target coating, changes in angle of incidence can affect the measurements. In standard solar field conditions, this error is less than 0.5%, but for special conditions a correction of the systematic error of up to 8% is proposed.
05/00231 A novel underground solar thermal heat storage unit cum heat exchanger for non air-conditioned buildings Kumar, R. and Kaushik, S.C. International Journal ~/" Global Energy Issues, 2003, 20, (2), 208-222. A novel passive space conditioning configuration is presented integrating a Solar Collector System, Underground Storage Tank and Novel Heat Exchanger. This Underground Solar Thermal Heat Exchanger (USTHE) provided improved sensible heating/cooling of air by employing a Novel Heat Exchanger (NHX). The dynamic performance of the storage tank in USTHE is modelled using the Finite Difference method accounting thermal stratification of water into three nodes (three isothermal segments). Analysis of NHX incorporated thermal heat transfer between water in the load loop of a storage tank and cross flowing air in the heat exchanger. Savings were incorporated in the building code in Matlab using a one-dimensional heat conduction equation. A wide range of experimental data was collected for validating the modelling results. Simulations were performed for several parameters viz. solar collector area (Ac), sizing of the storage tank, mass flow rate of water in collector loop (Wc) and load loop (WI) in daytime and night operations and air flow rate in novel heat exchanger. The effect of these simulations was predicted in terms of useful energy supplied by USTHE, thermal energy retaining period, collector temperature and averaged stratified temperature. Performance of USTHE is evaluated to give maximum heating potential. Effect of averaged isothermal segment temperature, stratification level and day and night flow rate combinations on heating potential is studied in great depth. USTHE supplied a peak heating potential of 5 kWh with a collector water flow rate of 252 kg/h and load water flow rate of 60 kg/h and obtained a maximum averaged temperature of stratified tank of 37.1°C. Building heating load savings were 6.98 kWh during daytime and 2.92 kWh at night on 11 December 2001. Dry bulb temperature of air increased by 10.2°C (peak value at 3.00 p.m.) on 1 January 2002 while water temperature decreased by 4.2°C.
05/00232 Bleaching and photodegradation of textile dyes by H202 and solar or ultraviolet radiation Costa, F. A. P. et al. Solar Energy, 2004, 77, (1), 29 35. The photo-oxidation of textile dyes Yellow Procion H-4R, Bright Blue Remazol (blue reagent-19), Red Procion H-E7B, and the mixture of the two last dyes were investigated. The efficiency of photo-oxidation was compared using hydrogen peroxide (30%) as a bleaching reagent,
32
Fuel and Energy Abstracts January 2005
05/00235 Characteristics of nanocrystalline CdS films fabricated by sonochemical, microwave and solution growth methods for solar cell applications Singh, V. P. Solar Energy Materials and Solar Cells, 2004, 81, (3), 293 303. Nanocrystalline CdS was synthesized by sonochemical and microwave methods. Characterization of nano-CdS was carried out by optical absorption, X-ray diffraction, TEM, SEM and EDX. A hyperbolic band model was used to calculate a shift in energy over that of the band gap of bulk CdS. Colloidal films comprising of nanocrystalline CdS were fabricated by the dip coating method. A comparison of optical absorption of CdS films on indium tin oxide (ITO)/glass by sonochemical and microwave methods was made with solution grown CdS films on ITO/glass. A blue shift in energy level at the nanoscale is demonstrated by optical absorption, and X-ray diffraction of nano-CdS shows a cubic structure. Electron microscopy studies with an FE-SEM and TEM show a particle size of 15 nm and diffraction patterns show a crystalline nature. Overall reduction in optical absorption due to blue shift is expected to result in higher performance, especially in shortcircuit currents in CdS/CdTe solar cells.
05•00236 Demand side management for remote area power supply systems incorporating solar irradiance model A1-Alawi, A. and Islam, S. M. Renewable Energy, 2004, 29, (13), 20272036. This paper presents a technique for generating the daily electricity load profile for remote areas in the Middle East from first principles, using diversified demand. The generated load profile includes the energy required to run a small desalination unit to provide the necessary freshwater. Demand side management (DSM) is used in this study to smooth out the daily peaks and fill valleys in the load curve to make the most efficient use of energy resources. Finally, the load profile is compared with real data for six houses collected from Safri area in the Sultanate of Oman. These data may be used as the basis to obtain load profiles of other remote areas of the Middle East since the weather and