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01345 International benchmarking and regulation: an application to European electricity distribution utilities
06 Electrical power supply and utilization (economics, policy, supplies, forecasts) study found that the main economic impact of the power interruptions, both planned and unplanned, is the loss of output in the industrial sector. In a typical year of power shortages, such as 2001, arising from a deficit in generation capacity, these losses can be as high as approximately US$81 million a year, which is approximately 0.65% of the country's gross domestic product (GDP). Also, the economic impact due to unplanned outages can be around US$45 million (0.3% of GDP) in a typical year. On average, these values for planned and unplanned outages are US$0.66 and US$1.08 per k W h of energy loss, respectively. It is also observed that 92% of the sampled industries have standby generation facilities to satisfy either, in full or partially, their own power requirements, which produced approximately 146 G W h of energy in 2001. The serious economic and environmental impacts of power interruptions, both planned and unplanned, underlines the importance of timely implementation of the long term least cost generation expansion plan and proper maintenance of transmission and distribution networks to ensure their high reliability. Therefore, it is clear that the utility needs to take immediate steps to improve its supply reliability in order to retain consumers and justify the existence of a centralized generation facility.
04101339 markets
Constructing forward price curves in electricity
Fleten, S.-E. and Lemming, J. Energy Economics, 2003, 25, (5), 409424. In this paper a method for constructing approximated high-resolution forward price curves in electricity markets is presented and analysed. Because a limited number of forward or futures contracts are traded in the market, only a limited picture of the theoretical continuous forward price curve is available to the analyst. The method combines the information contained in observed bid and ask prices with information from the forecasts generated by bottom-up models. As an example, information is used concerning the shape of the seasonal variation from a bottom-up model to improve the forward price curve quoted on the Nordic power exchange.
04/01340 CO2 mitigation costs of large-scale bioenergy technologies in competitive electricity markets Gustavsson, L. and Madlener, R. Energy, 2003, 28, (14), 1405-1425. In this study the impact of recent technological developments in large biomass-fired and natural-gas-fired cogeneration and condensing plants are compared and contrasted in terms of COz mitigation costs and under the conditions of a competitive electricity market. The CO2 mitigation cost indicates the minimum economic incentive required (e.g. in the form of a carbon t a x ) t o equal the cost of a less carbon extensive system with the cost of a reference system. The results show that CO2 mitigation costs are lower for biomass systems than for natural gas systems with decarbonization. However, in liberalized energy markets and given the socio-political will to implement carbon extensive energy systems, market-based policy measures are still required to make biomass and decarbonization options competitive and thus help them to penetrate the market. This cost of cogenerati0n plants, however, depends on the evaluation method used. The limitation of heat sinks is accounted for by expanding the reference entity to include both heat and power, as is typically recommended in life-cycle analysis, then the biomass-based gasification combined cycle (BIG/CC) technology turns out to be less expensive and to exhibit lower C O / mitigation costs than biomass-fired steam turbine plants. However, a heat credit granted to cogeneration systems that is based on avoided cost of separate heat production, puts the steam turbine technology despite its lower system efficiency at an advantage. In contrast, when a crediting method based on avoided electricity production in natural-gas-fired condensing plants is employed, the BIG/CC technology turns out to be more cost-competitive than the steam turbine technology for carbon tax levels beyond about $150/t C. Furthermore, steam turbine plants are able to compete with naturalgas-fired cogeneration plants at carbon tax levels higher than about $90/t C.
04/01341 Dissemination of solar photovoltaics: a study on the government programme to promote solar lantern in India Velayudhan, S. K. Energy Policy, 2003, 31, (14), 1509-1518. The study examines the reasons for the limited dissemination of solar lanterns in India. It uses 'diffusion of innovation' framework to examine the dissemination process. The impact of the characteristics of solar lantern on dissemination and also the communication within the community about the product are examined. To understand the influence of the characteristics of solar lantern on dissemination and the information source used by adopters, a survey of 188 users across 15 locations is carried out. The study shows that the benefits promoted by the government programme for disseminating solar lantern are not the reasons for purchase in most cases. The results suggest that the emphasis on subsidy by the support programme shifts the focus to the cost of the solar lantern than its benefits. Contrary to expectation there is no significant difference in the profile of early and late adopters. The
subsidy for solar lanterns and the targets set for government officials are the possible influence on the observed profile for adopter categories. The early majority who can afford the solar lantern and take up the innovation on its merits are expected to disseminate the innovation. The programme on the contrary not only fails to identify and promote to the early adopters, but focus on the disadvantaged groups. There are therefore no champions for the innovation and an absence of word-of-mouth communication. The information source is restricted to government agencies, while the potential user looks for evaluative information on the product from existing users. The application of 'diffusion of innovation' framework to understand the dissemination process of solar lantern suggests reworking the support programmes designed to promote solar lanterns. The lessons can be extended to programmes designed for dissemination of other solar photovoltaic products.
04/01342
Economic dispatch using fuzzy decision trees
Roa-Sepulveda, C. A. et al. Electric Power Systems Research, 2003, 66, (2), 115-122. Previous work has demonstrated the capability of decision trees (DT) in solving optimization problems for the economic dispatch (ED) problem including environmental constraints. This paper explains a new improvement in the DT technique by adding fuzzy logic (FL) to the unit limits and load (FLDT). By doing so, the numerical convergence of the overall technique improves. Furthermore, the generating cost obtained via FLDT is lower than that obtained with the classical formulation due to the fuzzyfying of the generating unit limits. Also, including the uncertainty of the load as a fuzzy load, new results are obtained that account not only for minimum cost but also for uncertainty. A 10 unit Chilean test system is used to validate and highlight the performance of this proposition.
04•01343
Electricity from bagasse in Zimbabwe
Mbohwa, C. and Fukuda, S. Biomass and Bioenergy, 2003, 25, (2), 197 207. Zimbabwe has suffered electrical power shortages resulting in electrical energy imports rising to between 40% and 50% of total energy needs. Electricity generation capacity has stagnated at around 2000 Megawatts (MW~) since 1985, when two thermal units totaling 440 MW~ were completed at Hwange. The effective capacity is 1.75 GWe. The current plan is to increase capacity by installing 600 M W , at Hwange at a cost of at least US$600 million. Raising this level of capital is difficult hence over the last 15 years there has been a failure to increase capacity. This article is based on a study of bagasse cogeneration in Zimbabwe and Mauritius conducted over a two-year period. It discusses technology improvements that can be made in the sugar sector to improve process and energy efficiency for the purposes of becoming an independent power producer that supplies power to the grid continuously throughout the year. Power plant investment in the sugar industry offers a bridging and realizable alternative for electricity generation in Zimbabwe. Investment in a 35 MWe bagasse (moisturized fibre left when sugar has been extracted from sugarcane) system would require a capital of about US$35 million using modern technology based on experiences in Mauritius and Reunion. A technical and economic evaluation and analysis reveals that bagasse power development is technically and economically feasible if electricity is priced at the long-term marginal cost. At current import prices, financial assistance from the global environment facility and/or the clean development mechanism of the Kyoto protocol would be necessary. The solving of the current political and economic problems in the country would pave the way for attracting a technical partner and development, of bagasse power using domestic and international financing.
04101344 Forecasting electricity spot-prices using linear univariate time-series models Cnaresma, J. C. et al. Applied Energy, 2004, 77, (l), 87 106. This paper studies the forecasting abilities of a battery of univariate models on hourly electricity spot prices, using data from the Leipzig Power Exchange. The specifications studied include autoregressive models, antoregressive-moving average models and unobserved component models. The results show that specifications, where each hour of the day is modelled separately present uniformly better forecasting properties than specifications for the whole time-series, and that the inclusion of simple probabilistic processes for the arrival of extreme price events can lead to improvements in the forecasting abilities of univariate models for electricity spot prices.
04/01345 International benchmarking and regulation: an application to European electricity distribution utilities Jamasb, T. and Pollitt, M. Energy Policy, 2003, 31, (15), 1609-1622. Due to a shortage of data and increased international mergers, national energy regulators are looking to international benchmarking analyses for help in setting price controls within incentive regulation. An international benchmarking study is presented of 63 regional electricity
Fuel and Energy Abstracts May 2004
183
06 Electrical power supply and utilization (economics, policy, supplies, forecasts) distribution utilities in six European countries that aims to illustrate the methodological and data issues encountered in the use of international benchmarking for utility regulation. The study examines the effect of the choice of benchmarking methods using DEA, COLS and SFA models. The report discusses what problems of international benchmarking are highlighted by the study and how they can be overcome.
04•01346 Lead-acid battery research and development a vital key to winning new business Bullock, K. R. Journal of Power Sources, 2003, 116, (1-2), 8-13. Battery strings are operated in a partial-state-of-charge mode (PSoC) in several new and changing applications for lead-acid batteries, in which the battery is seldom, if ever, fully charged or discharged. The lead battery industry faces new challenges as additional failure modes become evident in these PSoC applications. Without overcharge, cell imbalances caused by variations in cell temperature will cause premature failures. Valve-regulated lead-acid batteries are especially susceptible because of the heat generated by oxygen recombination at the negative plate. Improved thermal properties are shown by a proprietary battery design that combines absorptive glass mat and gelled acid technologies. Well-designed power systems are also required to reduce cell-to-cell temperature variations and, thereby, increase battery life.
04•01347 Korea
Life cycle inventory analysis for electricity in
Lee, K.-M. et al. Energy, 2004, 29, (1), 87-101. A life cycle inventory (LCI) analysis database that encompasses the entire Korean electrical energy grid was developed. The CO2 emission per functional unit of electricity, 1 kWh of usable electricity, was 0.49 kg/f.u. Contribution of direct emission o f CO2 to the total CO2 emission was around 95%. In the case of emissions of SOx, NOx, an d PM, contribution of the upstream processes including raw energy material extraction, transport, and fuel processing to the total emissions were 29%, 26%, and 43%, respectively. Emissions of air pollutants from power generation or direct emissions are much greater in quantity than those from the upstream processes. On the other hand, the opposite is true for the emissions of water pollutants. Bituminous coat was the largest source of emissions of air and water pollutants including CO2. Natural gas was the best fuel and anthracite coal was the worst fuel with respect to the direct and upstream emissions of air and water pollutants and wastes.
04/01348 Pricing criterions in presence of intra- and interzonal constraints Dicorato, M. et al. Electric Power Systems Research, 2003, 66, (2), 179186. Zonal partitioning is a method for solving the energy market, when network topology is taken into account. The reduction of the network to equivalent nodes representing zones, is unable to assess the intrazonal flows. This could give rise to questionable and unreliable results. In this paper, a methodology for solving the energy market together with transmission service, when either inter- or intra-zonal congestions occur, is proposed. A double-side auction, where both customers and sellers bid prices and quantities, is considered. Test results are evaluated using the proposed approach on IEEE-118 bus test grid.
04•01349 Progress of electricity from biomass, wind and photovoltaics in the European Union J~iger-Waldau, A. and Ossenbrink, H. Renewable and Sustainable Energy Reviews, 2004, 8, (2), 157-182. The world market for renewable energies is continuously growing. In particular, the wind energy and photovoltaic markets show yearly growth rates between 20 and over 30% in the last few years. Despite the fact that there are still discrepancies between the European Union and the USA how to deal with climate change, renewable energies will play an important role for the implementation of the Kyoto Protocol and the worldwide introduction of tradable green certificates. Apart from the electricity sector, renewable energy sources for the generation of heat and the use of environmental friendly bio-fuels for the transport sector will become more and more important in the future. This article tries to give an overview about the progress of renewable energies in Europe.
04101350 Prospects for lead-acid batteries in the new millennium Razelli, E. Journal of Power Sources, 2003, 116, (1-2), 2-3. The European lead-acid battery industry has been adversely affected by the collapse of the telecommunications and information technology expansion of the last several years and by general economic conditions in other sectors. This has had a substantial effect on the industrial battery market, particularly standby batteries, but the automotive business has been less affected. The industry has reacted to these continuing changes by consolidation and specialization within the
184 Fuel and Energy Abstracts
May 2004
different sectors but this alone is insufficient to ensure future success. The industry faces significant challenges to improve efficiencies through better manufacturing systems, but the development of new products for both existing and future applications is the greater priority. Advanced automotive batteries for Powernet applications and for hybrid electric vehicles, new types of standby and traction batteries and improvements to automotive batteries can all be achieved with lead-acid technology. This is a system with enormous potential for further improvement building on current strengths. This is a challenge to which the industry must respond in order to underpin the lead-acid battery as the most important electrical energy storage system.
04/01351 Prospects of autonomous/stand-alone hybrid (photo-voltaic + diesel + battery) power systems in commercial applications in hot regions Shaahid, S. M. and Elhadidy, M. A. Renewable Energy, 2004, 29, (2), 165 177. Most of the world's energy consumption is greatly dependent on fossil fuel, which is exhaustible and is being used extensively due to continuous escalation in the world's population and development. This valuable resource needs to be conserved and its alternatives need to be explored. In this perspective, dissemination and utilization of renewables such as solar energy has gained worldwide m o m e n t u m since the onset of the oil crises of the 1970s. Moreover, burning of fuels is the principal cause of air pollution, and possibly environmental warming. Saudi Arabia, being blessed with a fairly high level of solar radiation, is a suitable candidate for deployment of solar photovoltaic (PV) panels for power generation during crisis. Literature indicates that commercial/residential buildings in Saudi Arabia consume an estimated 10-45% of the total electrical energy generated/consumed. In the present study, hourly mean solar radiation data for the period 1986-1993 recorded at the solar radiation and meteorological monitoring station, Dhahran (26°32'N, 50°131E), Saudi Arabia, have been analysed to investigate the potential of utilizing hybrid (PV+diesel) power systems to meet the load requirements of a typical c0mmercial building (with an annual electrical energy demand of 620 000 kWh). The monthly average daily solar global irradiation for Dhahran ranges from 3.61 to 7.96 kWh/m 2. The hybrid systems considered in the present analysis consist of different combinations of PV panels/modules (different array sizes) supplemented with a battery storage unit and diesel back-up. The study shows that with a combination of 3700 m 2 PV together with 12 h of battery storage, the diesel back-up system has to provide 6% of the load demand. However, in the absence of a battery bank, about 56% of the load needs to be provided by the diesel system.
04/01352 Reliability of the Afam electric power generating station, Nigeria Eti, M. C. et al. Applied Energy, 2004, 77, (3), 309-315. Today's economic climate requires that each industry aims at achieving maximum production capability, while minimizing capital investment, e.g. in the maintenance function. This means finding ways to maximize equipment reliability and up-time and extend plant and equipment life through cost-effective maintenance. This paper surveys the performance of gas-turbine plants in Afam thermal-power station. The findings show that the financial impact of lost generation (through nonavailability) exceeded within a few years, the initial purchase price of the power plants and associated equipment.
04•01353 Role of hybrid (wind+diesel) power systems in meeting commercial loads Elhadidy, M. A. and Shaahid, S. M. Renewable Energy, 2004, 29, (1), 109-118. The utilization of energy from renewable sources, such as wind, is becoming increasingly attractive and is being widely used for the substitution of oil-produced energy, and eventually to minimize atmospheric degradation. Literature shows that commercial/residential buildings in Saudi Arabia consume an estimated 10-40% of the total electric energy generated. In the present study, hourly mean windspeed data for the period 1986-1997 recorded at the solar radiation and meteorological monitoring station, Dhahran (26°32 ' N, 50o13 ' E), Saudi Arabia, have been analysed to investigate/examine the role of hybrid (wind+diesel) energy conversion systems in meeting the load requirements of a typical commercial building (with annual electrical energy demand of 620 000 kWh). The monthly average wind speeds for Dhahran range from 4.1 to 6.4 m/s. The hybrid systems considered in the present analysis consist of different combinations of the commercial 10 kW wind energy conversion systems (WECS), supplemented with battery storage unit and diesel back-up. The study shows that with thirty 10 kW WECS and 3 days of battery storage, the diesel back-up system has to provide 19% of the load demand. However, in the absence of battery storage, about 40% of the load needs to be provided by the diesel system.
04101339 markets
Constructing forward price curves in electricity
Fleten, S.-E. and Lemming, J. Energy Economics, 2003, 25, (5), 409424. In this paper a method for constructing approximated high-resolution forward price curves in electricity markets is presented and analysed. Because a limited number of forward or futures contracts are traded in the market, only a limited picture of the theoretical continuous forward price curve is available to the analyst. The method combines the information contained in observed bid and ask prices with information from the forecasts generated by bottom-up models. As an example, information is used concerning the shape of the seasonal variation from a bottom-up model to improve the forward price curve quoted on the Nordic power exchange.
04/01340 CO2 mitigation costs of large-scale bioenergy technologies in competitive electricity markets Gustavsson, L. and Madlener, R. Energy, 2003, 28, (14), 1405-1425. In this study the impact of recent technological developments in large biomass-fired and natural-gas-fired cogeneration and condensing plants are compared and contrasted in terms of COz mitigation costs and under the conditions of a competitive electricity market. The CO2 mitigation cost indicates the minimum economic incentive required (e.g. in the form of a carbon t a x ) t o equal the cost of a less carbon extensive system with the cost of a reference system. The results show that CO2 mitigation costs are lower for biomass systems than for natural gas systems with decarbonization. However, in liberalized energy markets and given the socio-political will to implement carbon extensive energy systems, market-based policy measures are still required to make biomass and decarbonization options competitive and thus help them to penetrate the market. This cost of cogenerati0n plants, however, depends on the evaluation method used. The limitation of heat sinks is accounted for by expanding the reference entity to include both heat and power, as is typically recommended in life-cycle analysis, then the biomass-based gasification combined cycle (BIG/CC) technology turns out to be less expensive and to exhibit lower C O / mitigation costs than biomass-fired steam turbine plants. However, a heat credit granted to cogeneration systems that is based on avoided cost of separate heat production, puts the steam turbine technology despite its lower system efficiency at an advantage. In contrast, when a crediting method based on avoided electricity production in natural-gas-fired condensing plants is employed, the BIG/CC technology turns out to be more cost-competitive than the steam turbine technology for carbon tax levels beyond about $150/t C. Furthermore, steam turbine plants are able to compete with naturalgas-fired cogeneration plants at carbon tax levels higher than about $90/t C.
04/01341 Dissemination of solar photovoltaics: a study on the government programme to promote solar lantern in India Velayudhan, S. K. Energy Policy, 2003, 31, (14), 1509-1518. The study examines the reasons for the limited dissemination of solar lanterns in India. It uses 'diffusion of innovation' framework to examine the dissemination process. The impact of the characteristics of solar lantern on dissemination and also the communication within the community about the product are examined. To understand the influence of the characteristics of solar lantern on dissemination and the information source used by adopters, a survey of 188 users across 15 locations is carried out. The study shows that the benefits promoted by the government programme for disseminating solar lantern are not the reasons for purchase in most cases. The results suggest that the emphasis on subsidy by the support programme shifts the focus to the cost of the solar lantern than its benefits. Contrary to expectation there is no significant difference in the profile of early and late adopters. The
subsidy for solar lanterns and the targets set for government officials are the possible influence on the observed profile for adopter categories. The early majority who can afford the solar lantern and take up the innovation on its merits are expected to disseminate the innovation. The programme on the contrary not only fails to identify and promote to the early adopters, but focus on the disadvantaged groups. There are therefore no champions for the innovation and an absence of word-of-mouth communication. The information source is restricted to government agencies, while the potential user looks for evaluative information on the product from existing users. The application of 'diffusion of innovation' framework to understand the dissemination process of solar lantern suggests reworking the support programmes designed to promote solar lanterns. The lessons can be extended to programmes designed for dissemination of other solar photovoltaic products.
04/01342
Economic dispatch using fuzzy decision trees
Roa-Sepulveda, C. A. et al. Electric Power Systems Research, 2003, 66, (2), 115-122. Previous work has demonstrated the capability of decision trees (DT) in solving optimization problems for the economic dispatch (ED) problem including environmental constraints. This paper explains a new improvement in the DT technique by adding fuzzy logic (FL) to the unit limits and load (FLDT). By doing so, the numerical convergence of the overall technique improves. Furthermore, the generating cost obtained via FLDT is lower than that obtained with the classical formulation due to the fuzzyfying of the generating unit limits. Also, including the uncertainty of the load as a fuzzy load, new results are obtained that account not only for minimum cost but also for uncertainty. A 10 unit Chilean test system is used to validate and highlight the performance of this proposition.
04•01343
Electricity from bagasse in Zimbabwe
Mbohwa, C. and Fukuda, S. Biomass and Bioenergy, 2003, 25, (2), 197 207. Zimbabwe has suffered electrical power shortages resulting in electrical energy imports rising to between 40% and 50% of total energy needs. Electricity generation capacity has stagnated at around 2000 Megawatts (MW~) since 1985, when two thermal units totaling 440 MW~ were completed at Hwange. The effective capacity is 1.75 GWe. The current plan is to increase capacity by installing 600 M W , at Hwange at a cost of at least US$600 million. Raising this level of capital is difficult hence over the last 15 years there has been a failure to increase capacity. This article is based on a study of bagasse cogeneration in Zimbabwe and Mauritius conducted over a two-year period. It discusses technology improvements that can be made in the sugar sector to improve process and energy efficiency for the purposes of becoming an independent power producer that supplies power to the grid continuously throughout the year. Power plant investment in the sugar industry offers a bridging and realizable alternative for electricity generation in Zimbabwe. Investment in a 35 MWe bagasse (moisturized fibre left when sugar has been extracted from sugarcane) system would require a capital of about US$35 million using modern technology based on experiences in Mauritius and Reunion. A technical and economic evaluation and analysis reveals that bagasse power development is technically and economically feasible if electricity is priced at the long-term marginal cost. At current import prices, financial assistance from the global environment facility and/or the clean development mechanism of the Kyoto protocol would be necessary. The solving of the current political and economic problems in the country would pave the way for attracting a technical partner and development, of bagasse power using domestic and international financing.
04101344 Forecasting electricity spot-prices using linear univariate time-series models Cnaresma, J. C. et al. Applied Energy, 2004, 77, (l), 87 106. This paper studies the forecasting abilities of a battery of univariate models on hourly electricity spot prices, using data from the Leipzig Power Exchange. The specifications studied include autoregressive models, antoregressive-moving average models and unobserved component models. The results show that specifications, where each hour of the day is modelled separately present uniformly better forecasting properties than specifications for the whole time-series, and that the inclusion of simple probabilistic processes for the arrival of extreme price events can lead to improvements in the forecasting abilities of univariate models for electricity spot prices.
04/01345 International benchmarking and regulation: an application to European electricity distribution utilities Jamasb, T. and Pollitt, M. Energy Policy, 2003, 31, (15), 1609-1622. Due to a shortage of data and increased international mergers, national energy regulators are looking to international benchmarking analyses for help in setting price controls within incentive regulation. An international benchmarking study is presented of 63 regional electricity
Fuel and Energy Abstracts May 2004
183
06 Electrical power supply and utilization (economics, policy, supplies, forecasts) distribution utilities in six European countries that aims to illustrate the methodological and data issues encountered in the use of international benchmarking for utility regulation. The study examines the effect of the choice of benchmarking methods using DEA, COLS and SFA models. The report discusses what problems of international benchmarking are highlighted by the study and how they can be overcome.
04•01346 Lead-acid battery research and development a vital key to winning new business Bullock, K. R. Journal of Power Sources, 2003, 116, (1-2), 8-13. Battery strings are operated in a partial-state-of-charge mode (PSoC) in several new and changing applications for lead-acid batteries, in which the battery is seldom, if ever, fully charged or discharged. The lead battery industry faces new challenges as additional failure modes become evident in these PSoC applications. Without overcharge, cell imbalances caused by variations in cell temperature will cause premature failures. Valve-regulated lead-acid batteries are especially susceptible because of the heat generated by oxygen recombination at the negative plate. Improved thermal properties are shown by a proprietary battery design that combines absorptive glass mat and gelled acid technologies. Well-designed power systems are also required to reduce cell-to-cell temperature variations and, thereby, increase battery life.
04•01347 Korea
Life cycle inventory analysis for electricity in
Lee, K.-M. et al. Energy, 2004, 29, (1), 87-101. A life cycle inventory (LCI) analysis database that encompasses the entire Korean electrical energy grid was developed. The CO2 emission per functional unit of electricity, 1 kWh of usable electricity, was 0.49 kg/f.u. Contribution of direct emission o f CO2 to the total CO2 emission was around 95%. In the case of emissions of SOx, NOx, an d PM, contribution of the upstream processes including raw energy material extraction, transport, and fuel processing to the total emissions were 29%, 26%, and 43%, respectively. Emissions of air pollutants from power generation or direct emissions are much greater in quantity than those from the upstream processes. On the other hand, the opposite is true for the emissions of water pollutants. Bituminous coat was the largest source of emissions of air and water pollutants including CO2. Natural gas was the best fuel and anthracite coal was the worst fuel with respect to the direct and upstream emissions of air and water pollutants and wastes.
04/01348 Pricing criterions in presence of intra- and interzonal constraints Dicorato, M. et al. Electric Power Systems Research, 2003, 66, (2), 179186. Zonal partitioning is a method for solving the energy market, when network topology is taken into account. The reduction of the network to equivalent nodes representing zones, is unable to assess the intrazonal flows. This could give rise to questionable and unreliable results. In this paper, a methodology for solving the energy market together with transmission service, when either inter- or intra-zonal congestions occur, is proposed. A double-side auction, where both customers and sellers bid prices and quantities, is considered. Test results are evaluated using the proposed approach on IEEE-118 bus test grid.
04•01349 Progress of electricity from biomass, wind and photovoltaics in the European Union J~iger-Waldau, A. and Ossenbrink, H. Renewable and Sustainable Energy Reviews, 2004, 8, (2), 157-182. The world market for renewable energies is continuously growing. In particular, the wind energy and photovoltaic markets show yearly growth rates between 20 and over 30% in the last few years. Despite the fact that there are still discrepancies between the European Union and the USA how to deal with climate change, renewable energies will play an important role for the implementation of the Kyoto Protocol and the worldwide introduction of tradable green certificates. Apart from the electricity sector, renewable energy sources for the generation of heat and the use of environmental friendly bio-fuels for the transport sector will become more and more important in the future. This article tries to give an overview about the progress of renewable energies in Europe.
04101350 Prospects for lead-acid batteries in the new millennium Razelli, E. Journal of Power Sources, 2003, 116, (1-2), 2-3. The European lead-acid battery industry has been adversely affected by the collapse of the telecommunications and information technology expansion of the last several years and by general economic conditions in other sectors. This has had a substantial effect on the industrial battery market, particularly standby batteries, but the automotive business has been less affected. The industry has reacted to these continuing changes by consolidation and specialization within the
184 Fuel and Energy Abstracts
May 2004
different sectors but this alone is insufficient to ensure future success. The industry faces significant challenges to improve efficiencies through better manufacturing systems, but the development of new products for both existing and future applications is the greater priority. Advanced automotive batteries for Powernet applications and for hybrid electric vehicles, new types of standby and traction batteries and improvements to automotive batteries can all be achieved with lead-acid technology. This is a system with enormous potential for further improvement building on current strengths. This is a challenge to which the industry must respond in order to underpin the lead-acid battery as the most important electrical energy storage system.
04/01351 Prospects of autonomous/stand-alone hybrid (photo-voltaic + diesel + battery) power systems in commercial applications in hot regions Shaahid, S. M. and Elhadidy, M. A. Renewable Energy, 2004, 29, (2), 165 177. Most of the world's energy consumption is greatly dependent on fossil fuel, which is exhaustible and is being used extensively due to continuous escalation in the world's population and development. This valuable resource needs to be conserved and its alternatives need to be explored. In this perspective, dissemination and utilization of renewables such as solar energy has gained worldwide m o m e n t u m since the onset of the oil crises of the 1970s. Moreover, burning of fuels is the principal cause of air pollution, and possibly environmental warming. Saudi Arabia, being blessed with a fairly high level of solar radiation, is a suitable candidate for deployment of solar photovoltaic (PV) panels for power generation during crisis. Literature indicates that commercial/residential buildings in Saudi Arabia consume an estimated 10-45% of the total electrical energy generated/consumed. In the present study, hourly mean solar radiation data for the period 1986-1993 recorded at the solar radiation and meteorological monitoring station, Dhahran (26°32'N, 50°131E), Saudi Arabia, have been analysed to investigate the potential of utilizing hybrid (PV+diesel) power systems to meet the load requirements of a typical c0mmercial building (with an annual electrical energy demand of 620 000 kWh). The monthly average daily solar global irradiation for Dhahran ranges from 3.61 to 7.96 kWh/m 2. The hybrid systems considered in the present analysis consist of different combinations of PV panels/modules (different array sizes) supplemented with a battery storage unit and diesel back-up. The study shows that with a combination of 3700 m 2 PV together with 12 h of battery storage, the diesel back-up system has to provide 6% of the load demand. However, in the absence of a battery bank, about 56% of the load needs to be provided by the diesel system.
04/01352 Reliability of the Afam electric power generating station, Nigeria Eti, M. C. et al. Applied Energy, 2004, 77, (3), 309-315. Today's economic climate requires that each industry aims at achieving maximum production capability, while minimizing capital investment, e.g. in the maintenance function. This means finding ways to maximize equipment reliability and up-time and extend plant and equipment life through cost-effective maintenance. This paper surveys the performance of gas-turbine plants in Afam thermal-power station. The findings show that the financial impact of lost generation (through nonavailability) exceeded within a few years, the initial purchase price of the power plants and associated equipment.
04•01353 Role of hybrid (wind+diesel) power systems in meeting commercial loads Elhadidy, M. A. and Shaahid, S. M. Renewable Energy, 2004, 29, (1), 109-118. The utilization of energy from renewable sources, such as wind, is becoming increasingly attractive and is being widely used for the substitution of oil-produced energy, and eventually to minimize atmospheric degradation. Literature shows that commercial/residential buildings in Saudi Arabia consume an estimated 10-40% of the total electric energy generated. In the present study, hourly mean windspeed data for the period 1986-1997 recorded at the solar radiation and meteorological monitoring station, Dhahran (26°32 ' N, 50o13 ' E), Saudi Arabia, have been analysed to investigate/examine the role of hybrid (wind+diesel) energy conversion systems in meeting the load requirements of a typical commercial building (with annual electrical energy demand of 620 000 kWh). The monthly average wind speeds for Dhahran range from 4.1 to 6.4 m/s. The hybrid systems considered in the present analysis consist of different combinations of the commercial 10 kW wind energy conversion systems (WECS), supplemented with battery storage unit and diesel back-up. The study shows that with thirty 10 kW WECS and 3 days of battery storage, the diesel back-up system has to provide 19% of the load demand. However, in the absence of battery storage, about 40% of the load needs to be provided by the diesel system.