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01917 All-year-round harvesting of short rotation coppice eucalyptus compared with the delivered costs of biomass from more conventional short season, harvesting systems
07 Altemafive energy sources (bioconversion energy) This paper estimates residential, industrial, and total electricity demand by a partial-adjustment approach and by a simultaneous equation approach. Simultaneous equation models are more appropriate since they provide negative price elasticity estimates for the residential, industrial and total electricity samples. Flow-adjustment models yield positive price elasticity estimates in some cases, suggesting they fail to identify proper supply considerations that may be influencing prices. The simultaneous equation approach suggests that residential customers are more price sensitive than industrial customers. Weather seems to have the greatest impact on the residential sector, and cold weather appears to affect demand more than hot weather.
04/01914 The impact of electricity supply on economic growth in Sri Lanka Morimoto, R. and Hope, C. Energy Economics, 2004, 26, (1), 77-85. A previous study by Yang has found a bi-directional causal relationship between gross domestic product and electricity consumption in Taiwan, ROC. This study applies Yang's model to examine the impact of electricity supply on economic growth in Sri Lanka. A study by Morimoto and Hope found that the expected increase in economic output due to increased electricity supply (parameter EO) plays a crucial role in their cost benefit analysis model. This shows that the application of Yang's regression analysis is one possible approach to estimate a better range for the parameter EO. The estimated figure is that an extra output of Rs88 000-137 000 ($USl120-1740) for every 1 MW h increase in electricity supply.
04/01915 Transmission congestion and voltage profile management coordination in competitive electricity markets Yamin, H. Y. and Shahidehpour, S. M. International Journal of Electrical Power & Energy Systems, 2003, 25, (10), 849-861. This paper describes a generalized active/reactive iterative coordination process between GENCOs and the Independent System Operator (ISO) for active (transmission congestion) and reactive (voltage profile) management in the day-ahead market. GENCOs apply priced-based unit commitment without transmission and voltage security constraints, schedule their units and submit their initial bids to the ISO. The ISO executes congestion and voltage profile management for eliminating transmission and voltage profile violations. If violations are not eliminated, the ISO minimizes the transmission and voltage profile violations and sends a signal via the Internet to GENCOs. GENCOs reschedule their units taking into account the ISO signals and submit modified bids to the ISO. The voltage problem is addressed and a linear model is formulated and used in the proposed method. The voltage problem is formulated as a linear programming with a block-angular structure and Dantzig-Wolfe decomposition is applied to generate several smaller problems for a faster and easier solution of large-scale power systems. Two 36 unit GENCOs are used to demonstrate the performance of the proposed generalized active/ reactive coordination algorithm.
07
ALTERNATIVE ENERGY SOURCES Bioconversion energy
04/01916 Above-ground biomass production and biomass equations for even-aged Gmelina arborea (ROXB) plantations in south-western Nigeria Onyekwelu, J. C. Biomass and Bioenergy, 2004, 26, (1), 39-46. Above-ground biomass production was estimated for Gmelina arborea (Roxb) plantations (ages 5 21 years) in Oluwa Forest Reserve, Nigeria. A total of 120 trees were harvested and weighed to provide data for the estimation of biomass as well as for developing biomass equations. The results showed that Gmelina has high biomass yield, ranging from 83.2 t h a - 1 (5 years) to 394.9 tha 1 (21 years). Mean annual biomass increment varied from 16.2 to 20.9 tha 1 y r - .1 Average biomass allocations to different components of the tree were as follows: stem about 84%; branch 13% and foliage 3%. The high biomass values were attributed to fast growth, high stand density (range: 837 1275 stems ha 1) and good site conditions in the study area. Biomass values of the various tree components (stem, branch and foliage) as well as total above-ground biomass (TAGB) were regressed with diameter at breast height (dbh) on the one hand (equation form 1), and with dbh and total height (in the form of D2H) on the other (equation form 2), with the
266
Fuel and Energy Abstracts July 2004
aim of choosing the most suitable equation form. All equations generated had very high adjusted R 2 and very low standard error of estimate, Residuals for both equation forms were normally and randomly distributed. Only little improvement in the ability of the equations to explain the variations in biomass was achieved by including the variable of total height. Considering the ease and accuracy in obtaining dbh data and the enormous time, errors and difficulty in obtaining height data, the equation form involving only dbh data as independent variable was recommended for use in estimating biomass for Gmelina in Oluwa forest reserve.
04/01917 All-year-round harvesting of short rotation coppice eucalyptus compared with the delivered costs of biomass from more conventional short season, harvesting systems Sims, R. E. H. and Venturi, P. Biomass and Bioenergy, 2004, 26, (l), 27-37. This study attempted to define the optimum harvesting, processing and transport system in terms of the cost per tonne of delivering biomass produced from a commercial short rotation coppice crop to a 10 MWe bioenergy conversion plant 25 km away. Harvesting the crop during one short seasonal period of the year results in the need to store most of the material for between one to 12 months in order to provide a continual supply of feedstock. Storage of large volumes of biomass is costly and also results in dry matter losses over time. An alternative system would be to harvest small areas as required every few weeks throughout the year. This would enable cheaper, lower performance equipment to be used and hence provide a continual supply of biomass feedstock for delivery to the plant. Four systems of conventionally harvesting the biomass during one short seasonal period of 8-10 weeks were compared with two systems of harvesting it continually throughout the year. Whether the biomass is stored on the farms after harvest to allow for transpirational drying or at the plant was also compared. All-year-round harvesting using a simple tractor-mounted circular saw showed cost benefits in terms of $/GJ of energy delivered to the bioenergy plant but the performance assumptions made will require confirmation by field monitoring. A sensitivity analysis was conducted on several key parameters.
04/01918 Biomass energy technologies for rural infrastructure and village power - opportunities and challenges in the context of global climate change concerns Kishore, V. V. N. et al. Energy Policy, 2004, 32, (6), 801-810. The potential and role of biomass resources in developing countries for addressing global climate change concerns are highlighted using India as a case study. Promotion of technologies, which use biomass more efficiently, is seen as a key strategy to integrate the concerns of both developing countries and developed countries. The role of various biomass technologies for improving rural infrastructure and village power is discussed in detail. A vision of establishing and running a chain of rural energy service companies, operating with a basket of devices and technologies, under the general provisions of CDM, is examined for commercialization and mainstreaming of biomass technologies which have achieved reasonable levels of maturity.
04/01919 Conflict over biomass energy development in the United Kingdom: some observations and lessons from England and Wales Upreti, B. R. Energy Policy, 2004, 32, (6), 785-800. The aim of this paper is to examine the causes of conflict over biomass energy development in the United Kingdom. This paper discusses social dimensions of development of biomass power plants. Based on the four case studies from England and Wales this paper examines impacts of public oppositions on planning permission. This paper revels that public opposition is one of the major obstacles to promote biomass energy. Though local communities value environmental benefits of biomass energy, they concern more on the immediate negative local effects of power plants to their areas. Main sources of public conflict over biomass energy development were related to location of the plant, perceived risks, and negative effects to ecology and landscape compared to few economic benefits to local people. Other factors contributing to the conflict were feeling of injustice, weak public relation strategy of the developers and low level of awareness. The paper concludes that biomass energy can be promoted only if all actors: the central government, developers, local councils, environmental concern groups and local communities make collective efforts. Such collaborative efforts need drastic shift in the current approach of biomass energy development.
04/01920 Energetic and economics of traditional gur preparation: a case study in Ganjam district of Orissa, India Pattnayak, P. K. and Misra, M. K. Biomass andBioenergy, 2004, 26, (1), 79-88.
04/01914 The impact of electricity supply on economic growth in Sri Lanka Morimoto, R. and Hope, C. Energy Economics, 2004, 26, (1), 77-85. A previous study by Yang has found a bi-directional causal relationship between gross domestic product and electricity consumption in Taiwan, ROC. This study applies Yang's model to examine the impact of electricity supply on economic growth in Sri Lanka. A study by Morimoto and Hope found that the expected increase in economic output due to increased electricity supply (parameter EO) plays a crucial role in their cost benefit analysis model. This shows that the application of Yang's regression analysis is one possible approach to estimate a better range for the parameter EO. The estimated figure is that an extra output of Rs88 000-137 000 ($USl120-1740) for every 1 MW h increase in electricity supply.
04/01915 Transmission congestion and voltage profile management coordination in competitive electricity markets Yamin, H. Y. and Shahidehpour, S. M. International Journal of Electrical Power & Energy Systems, 2003, 25, (10), 849-861. This paper describes a generalized active/reactive iterative coordination process between GENCOs and the Independent System Operator (ISO) for active (transmission congestion) and reactive (voltage profile) management in the day-ahead market. GENCOs apply priced-based unit commitment without transmission and voltage security constraints, schedule their units and submit their initial bids to the ISO. The ISO executes congestion and voltage profile management for eliminating transmission and voltage profile violations. If violations are not eliminated, the ISO minimizes the transmission and voltage profile violations and sends a signal via the Internet to GENCOs. GENCOs reschedule their units taking into account the ISO signals and submit modified bids to the ISO. The voltage problem is addressed and a linear model is formulated and used in the proposed method. The voltage problem is formulated as a linear programming with a block-angular structure and Dantzig-Wolfe decomposition is applied to generate several smaller problems for a faster and easier solution of large-scale power systems. Two 36 unit GENCOs are used to demonstrate the performance of the proposed generalized active/ reactive coordination algorithm.
07
ALTERNATIVE ENERGY SOURCES Bioconversion energy
04/01916 Above-ground biomass production and biomass equations for even-aged Gmelina arborea (ROXB) plantations in south-western Nigeria Onyekwelu, J. C. Biomass and Bioenergy, 2004, 26, (1), 39-46. Above-ground biomass production was estimated for Gmelina arborea (Roxb) plantations (ages 5 21 years) in Oluwa Forest Reserve, Nigeria. A total of 120 trees were harvested and weighed to provide data for the estimation of biomass as well as for developing biomass equations. The results showed that Gmelina has high biomass yield, ranging from 83.2 t h a - 1 (5 years) to 394.9 tha 1 (21 years). Mean annual biomass increment varied from 16.2 to 20.9 tha 1 y r - .1 Average biomass allocations to different components of the tree were as follows: stem about 84%; branch 13% and foliage 3%. The high biomass values were attributed to fast growth, high stand density (range: 837 1275 stems ha 1) and good site conditions in the study area. Biomass values of the various tree components (stem, branch and foliage) as well as total above-ground biomass (TAGB) were regressed with diameter at breast height (dbh) on the one hand (equation form 1), and with dbh and total height (in the form of D2H) on the other (equation form 2), with the
266
Fuel and Energy Abstracts July 2004
aim of choosing the most suitable equation form. All equations generated had very high adjusted R 2 and very low standard error of estimate, Residuals for both equation forms were normally and randomly distributed. Only little improvement in the ability of the equations to explain the variations in biomass was achieved by including the variable of total height. Considering the ease and accuracy in obtaining dbh data and the enormous time, errors and difficulty in obtaining height data, the equation form involving only dbh data as independent variable was recommended for use in estimating biomass for Gmelina in Oluwa forest reserve.
04/01917 All-year-round harvesting of short rotation coppice eucalyptus compared with the delivered costs of biomass from more conventional short season, harvesting systems Sims, R. E. H. and Venturi, P. Biomass and Bioenergy, 2004, 26, (l), 27-37. This study attempted to define the optimum harvesting, processing and transport system in terms of the cost per tonne of delivering biomass produced from a commercial short rotation coppice crop to a 10 MWe bioenergy conversion plant 25 km away. Harvesting the crop during one short seasonal period of the year results in the need to store most of the material for between one to 12 months in order to provide a continual supply of feedstock. Storage of large volumes of biomass is costly and also results in dry matter losses over time. An alternative system would be to harvest small areas as required every few weeks throughout the year. This would enable cheaper, lower performance equipment to be used and hence provide a continual supply of biomass feedstock for delivery to the plant. Four systems of conventionally harvesting the biomass during one short seasonal period of 8-10 weeks were compared with two systems of harvesting it continually throughout the year. Whether the biomass is stored on the farms after harvest to allow for transpirational drying or at the plant was also compared. All-year-round harvesting using a simple tractor-mounted circular saw showed cost benefits in terms of $/GJ of energy delivered to the bioenergy plant but the performance assumptions made will require confirmation by field monitoring. A sensitivity analysis was conducted on several key parameters.
04/01918 Biomass energy technologies for rural infrastructure and village power - opportunities and challenges in the context of global climate change concerns Kishore, V. V. N. et al. Energy Policy, 2004, 32, (6), 801-810. The potential and role of biomass resources in developing countries for addressing global climate change concerns are highlighted using India as a case study. Promotion of technologies, which use biomass more efficiently, is seen as a key strategy to integrate the concerns of both developing countries and developed countries. The role of various biomass technologies for improving rural infrastructure and village power is discussed in detail. A vision of establishing and running a chain of rural energy service companies, operating with a basket of devices and technologies, under the general provisions of CDM, is examined for commercialization and mainstreaming of biomass technologies which have achieved reasonable levels of maturity.
04/01919 Conflict over biomass energy development in the United Kingdom: some observations and lessons from England and Wales Upreti, B. R. Energy Policy, 2004, 32, (6), 785-800. The aim of this paper is to examine the causes of conflict over biomass energy development in the United Kingdom. This paper discusses social dimensions of development of biomass power plants. Based on the four case studies from England and Wales this paper examines impacts of public oppositions on planning permission. This paper revels that public opposition is one of the major obstacles to promote biomass energy. Though local communities value environmental benefits of biomass energy, they concern more on the immediate negative local effects of power plants to their areas. Main sources of public conflict over biomass energy development were related to location of the plant, perceived risks, and negative effects to ecology and landscape compared to few economic benefits to local people. Other factors contributing to the conflict were feeling of injustice, weak public relation strategy of the developers and low level of awareness. The paper concludes that biomass energy can be promoted only if all actors: the central government, developers, local councils, environmental concern groups and local communities make collective efforts. Such collaborative efforts need drastic shift in the current approach of biomass energy development.
04/01920 Energetic and economics of traditional gur preparation: a case study in Ganjam district of Orissa, India Pattnayak, P. K. and Misra, M. K. Biomass andBioenergy, 2004, 26, (1), 79-88.