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01937 Thin layer convective solar drying and mathematical modeling of prickly pear peel (Opuntia ficus indica)
07 Altemative energy sources (solar energy) determined. Surface areas of between 770 and 879 m 2 g 1 were achieved. The yield of activated carbon was mostly less than 20 wt% of the original biomass. The five biomass samples were also pyrolysed in a thermogravimetric analyser. The thermal degradation of the biomass samples were discussed in terms of the thermal degradation of the main components of the biomass, cellulose, hemicellulose and lignin.
04/01930 Thermodynamic analysis and optimization of a combined adsorption heating and cooling system Yeung, K. H. and Sumathy, K. International Journal of Energy Research, 2003, 27, (15), 1299-1315. This paper presents the description and operation of a solar-powered hybrid adsorption ice-maker with activated carbon fibre and methanol as the working pair. The analysis indicates that for the given amount of adsorbent/adsorbate, by adapting more adsorbers instead of conventionally used single adsorber bed, the performance of the adsorption system can be improved. Also, the results show that compared to the change in mass of the adsorbent, the amount of water in the tank influences the system performance to a greater extent. Hence, in the present work, an optimum design has been outlined for a solar hybrid adsorption system employing an evacuated vacuum tube collector with an exposed area of 2 m 2 as the heat source. It is shown that, an optimized adsorption system could achieve a coefficient of performance (COP) of about 0.56 and produce around 6 kg of ice a day.
Geothermal energy 04/01931 Geothermal energy sources for water productionsocio-economic effects and people's wishes on Milos island: a case study Manologlou, E. et al. Energy Policy, 2004, 32, (5), 623-633. The scope of the article is to examine the local residents' views and opinions on the effects of the construction of a desalination plant on the island of Milos (Greece) which suffers - as many other islands in Cyclades - from lack of water. In particular, (1) to identify the current situation regarding the water supply on the island, (2) to examine the effects that the construction of the desalination plant will have on the local development, (3) to identify the different sectors of every day life which may be affected the most by better quality of water and (4) to examine the views concerning the environmental effects during project construction and operation. The main conclusion is that: Most of the inhabitants perceive the proposed project as beneficial for different sectors of the local development (mining, agriculture, tourism) and for every day life.
04/01932 Thermal conductivity measurement of geothermal cementing systems: an experimental comparison between the line source and Jaeger methods Garcfa-Gutierrez, A. and Espinosa-Paredes, G. Energy Conversion and Management, 2004, 45, (5), 755-764. Two different methods to determine the effective thermal conductivity of six Mexican cementing systems used in geothermal well completion were compared in the temperature range from 28 to 200°C. Measurements were taken using the classical line-source method and the Jaeger method. The experimental thermal conductivity uncertainties were 4% and 11.8% for the line source and Jaeger's methods, respectively.
04/01933 Generation of typical solar radiation data for Istanbul, Turkey Bulut, H. et al. International Journal of Energy Research, 2003, 27, (9), 847-855. Typical solar radiation data are very important as input in modelling, designing and performance evaluation of solar energy applications. In this study, typical solar radiation data were obtained for Istanbul, Turkey both from measured data and synthetic generation. Firstly, a test reference year for daily global solar radiation on a horizontal surface was generated using 19 years measured data. The daily global solar radiation as typical data for Istanbul was presented throughout a year in a tabular form. Secondly, the daily global solar radiation for Istanbul was expressed with a trigonometric equation using long-term measured data. It is expected that the typical data and the equation
Fuel and Energy Abstracts
04/01934
Recent developments in photovoltaics
Green, M. A. Solar Energy, 2004, 76, (1-3), 3-8. The photovoltaic market is booming with over 30% per annum compounded growth over the last 5 years. The government-subsidized urban-residential use of photovoltaics, particularly in Germany and Japan, is driving this sustained growth. Most of the solar cells being supplied to this market are 'first generation' devices based on crystalline or multi-crystalline silicon wafers. 'Second generation' thin-film solar cells based on amorphous silicon/hydrogen alloys or polycrystalline compound semiconductors are starting to appear on the market in increasing volume. Australian contributions in this area are the thin-film polycrystalline silicon-on-glass technology developed by Pacific Solar and the dye sensitized nanocrystalline titanium cells developed by Sustainable Technologies International. In these thinfilm approaches, the major material cost component is usually the glass sheet onto which the film is deposited. After reviewing the present state of development of both cell and application technologies, the likely future development of photovoltaics is outlined.
04/01935 Thailand's solar white elephants: an analysis of 15 yr of solar battery charging programmes in northern Thailand Green, D. Energy Policy, 2004, 32, (6), 747-760. The use of decentralized renewable energy technologies to provide rural electrification in developing countries has been a common topic of analysis and policy debate for more than two decades. Unfortunately, a lack of empirical evidence about the field performance of these technologies is a significant barrier to making sound policy decisions about them. Compounded by minimal information sharing between stakeholders, this situation has frequently allowed duplication of inefficient policies. This issue is addressed here by providing empirical evidence gathered from field visits and interviews about the largest government subsidized solar battery charging programme in the world. This analysis highlights the different policies of departments responsible and discusses them with specific attention to their technical, social and economic components. Field study results from over 50 villages in the north of Thailand suggest about 60 per cent of these systems are no longer operational. Many of the technical failures observed are attributed to social factors, as well as flawed implementation strategies.
04/01936 The potential of solar electric power for meeting future US energy needs: a comparison of projections of solar electric energy generation and Arctic National Wildlife Refuge oil production Byrne, J. et al. Energy Policy, 2004, 32, (2), 289-297. This paper compares the potential contribution of solar electric power in the form of photovoltaics to meet future US energy demand with the projected volume of oil estimated to be available in the Arctic National Wildlife Refuge. Such a comparison has practical value since it directly addresses a key policy choice under consideration in the new century, namely, that between one of the most promising untapped oil deposits in the world and one of the most rapidly growing renewable energy options.
04/01937 Thin layer convective solar drying and mathematical modeling of prickly pear peel (Opuntia ficus indica)
Solar energy
268
derived will be useful to the designers of solar energy systems as well as those who need to have fairly good estimates of daily global solar radiation for Istanbul.
July 2004
Lahsasni, S. et al. Energy, 2004, 29, (2), 211-224. This paper presents the thin layer convective solar drying and mathematical modelling of prickly pear peel. For these purposes, an indirect forced convection solar dryer consisting of a solar air collector, an auxiliary heater, a circulation fan and a drying cabinet is used for drying experiments. Moreover, the prickly pear peel is sufficiently dried in the ranges of 32 to 36°C of ambient air temperature, 50 to 60°C of drying air temperature, 23 to 34% of relative humidity, 0.0277 to 0.0833 m 3 /s of drying air flow rate and 200 to 950 W/m 2 of daily solar radiation. The experimental drying curves show only a falling drying rate period. The main factor in controlling the drying rate was found to be the drying air temperature. The drying rate equation is determined empirically from the characteristic drying curve. Also, the experimental drying curves obtained were fitted to a number of mathematical models. The Midilli-Kucuk drying model was found to satisfactorily describe the solar drying curves of prickly ~ear peel with a correlation coefficient (r) of 0.9998 and chi-square (X) of 4.6572 10-5.
04/01930 Thermodynamic analysis and optimization of a combined adsorption heating and cooling system Yeung, K. H. and Sumathy, K. International Journal of Energy Research, 2003, 27, (15), 1299-1315. This paper presents the description and operation of a solar-powered hybrid adsorption ice-maker with activated carbon fibre and methanol as the working pair. The analysis indicates that for the given amount of adsorbent/adsorbate, by adapting more adsorbers instead of conventionally used single adsorber bed, the performance of the adsorption system can be improved. Also, the results show that compared to the change in mass of the adsorbent, the amount of water in the tank influences the system performance to a greater extent. Hence, in the present work, an optimum design has been outlined for a solar hybrid adsorption system employing an evacuated vacuum tube collector with an exposed area of 2 m 2 as the heat source. It is shown that, an optimized adsorption system could achieve a coefficient of performance (COP) of about 0.56 and produce around 6 kg of ice a day.
Geothermal energy 04/01931 Geothermal energy sources for water productionsocio-economic effects and people's wishes on Milos island: a case study Manologlou, E. et al. Energy Policy, 2004, 32, (5), 623-633. The scope of the article is to examine the local residents' views and opinions on the effects of the construction of a desalination plant on the island of Milos (Greece) which suffers - as many other islands in Cyclades - from lack of water. In particular, (1) to identify the current situation regarding the water supply on the island, (2) to examine the effects that the construction of the desalination plant will have on the local development, (3) to identify the different sectors of every day life which may be affected the most by better quality of water and (4) to examine the views concerning the environmental effects during project construction and operation. The main conclusion is that: Most of the inhabitants perceive the proposed project as beneficial for different sectors of the local development (mining, agriculture, tourism) and for every day life.
04/01932 Thermal conductivity measurement of geothermal cementing systems: an experimental comparison between the line source and Jaeger methods Garcfa-Gutierrez, A. and Espinosa-Paredes, G. Energy Conversion and Management, 2004, 45, (5), 755-764. Two different methods to determine the effective thermal conductivity of six Mexican cementing systems used in geothermal well completion were compared in the temperature range from 28 to 200°C. Measurements were taken using the classical line-source method and the Jaeger method. The experimental thermal conductivity uncertainties were 4% and 11.8% for the line source and Jaeger's methods, respectively.
04/01933 Generation of typical solar radiation data for Istanbul, Turkey Bulut, H. et al. International Journal of Energy Research, 2003, 27, (9), 847-855. Typical solar radiation data are very important as input in modelling, designing and performance evaluation of solar energy applications. In this study, typical solar radiation data were obtained for Istanbul, Turkey both from measured data and synthetic generation. Firstly, a test reference year for daily global solar radiation on a horizontal surface was generated using 19 years measured data. The daily global solar radiation as typical data for Istanbul was presented throughout a year in a tabular form. Secondly, the daily global solar radiation for Istanbul was expressed with a trigonometric equation using long-term measured data. It is expected that the typical data and the equation
Fuel and Energy Abstracts
04/01934
Recent developments in photovoltaics
Green, M. A. Solar Energy, 2004, 76, (1-3), 3-8. The photovoltaic market is booming with over 30% per annum compounded growth over the last 5 years. The government-subsidized urban-residential use of photovoltaics, particularly in Germany and Japan, is driving this sustained growth. Most of the solar cells being supplied to this market are 'first generation' devices based on crystalline or multi-crystalline silicon wafers. 'Second generation' thin-film solar cells based on amorphous silicon/hydrogen alloys or polycrystalline compound semiconductors are starting to appear on the market in increasing volume. Australian contributions in this area are the thin-film polycrystalline silicon-on-glass technology developed by Pacific Solar and the dye sensitized nanocrystalline titanium cells developed by Sustainable Technologies International. In these thinfilm approaches, the major material cost component is usually the glass sheet onto which the film is deposited. After reviewing the present state of development of both cell and application technologies, the likely future development of photovoltaics is outlined.
04/01935 Thailand's solar white elephants: an analysis of 15 yr of solar battery charging programmes in northern Thailand Green, D. Energy Policy, 2004, 32, (6), 747-760. The use of decentralized renewable energy technologies to provide rural electrification in developing countries has been a common topic of analysis and policy debate for more than two decades. Unfortunately, a lack of empirical evidence about the field performance of these technologies is a significant barrier to making sound policy decisions about them. Compounded by minimal information sharing between stakeholders, this situation has frequently allowed duplication of inefficient policies. This issue is addressed here by providing empirical evidence gathered from field visits and interviews about the largest government subsidized solar battery charging programme in the world. This analysis highlights the different policies of departments responsible and discusses them with specific attention to their technical, social and economic components. Field study results from over 50 villages in the north of Thailand suggest about 60 per cent of these systems are no longer operational. Many of the technical failures observed are attributed to social factors, as well as flawed implementation strategies.
04/01936 The potential of solar electric power for meeting future US energy needs: a comparison of projections of solar electric energy generation and Arctic National Wildlife Refuge oil production Byrne, J. et al. Energy Policy, 2004, 32, (2), 289-297. This paper compares the potential contribution of solar electric power in the form of photovoltaics to meet future US energy demand with the projected volume of oil estimated to be available in the Arctic National Wildlife Refuge. Such a comparison has practical value since it directly addresses a key policy choice under consideration in the new century, namely, that between one of the most promising untapped oil deposits in the world and one of the most rapidly growing renewable energy options.
04/01937 Thin layer convective solar drying and mathematical modeling of prickly pear peel (Opuntia ficus indica)
Solar energy
268
derived will be useful to the designers of solar energy systems as well as those who need to have fairly good estimates of daily global solar radiation for Istanbul.
July 2004
Lahsasni, S. et al. Energy, 2004, 29, (2), 211-224. This paper presents the thin layer convective solar drying and mathematical modelling of prickly pear peel. For these purposes, an indirect forced convection solar dryer consisting of a solar air collector, an auxiliary heater, a circulation fan and a drying cabinet is used for drying experiments. Moreover, the prickly pear peel is sufficiently dried in the ranges of 32 to 36°C of ambient air temperature, 50 to 60°C of drying air temperature, 23 to 34% of relative humidity, 0.0277 to 0.0833 m 3 /s of drying air flow rate and 200 to 950 W/m 2 of daily solar radiation. The experimental drying curves show only a falling drying rate period. The main factor in controlling the drying rate was found to be the drying air temperature. The drying rate equation is determined empirically from the characteristic drying curve. Also, the experimental drying curves obtained were fitted to a number of mathematical models. The Midilli-Kucuk drying model was found to satisfactorily describe the solar drying curves of prickly ~ear peel with a correlation coefficient (r) of 0.9998 and chi-square (X) of 4.6572 10-5.