Showing papers on "Power station published in 2003"

Wind energy explained: Theory, Design, and application [Book Review]

Abstract: WIND ENERGY EXPLAINED: THEORY, Design, and Application, by J.F. Manwell, J.G. McGowan, and A.L. Rogers, is intended to provide both a thorough and highly accessible introduction to the cross-disciplinary field of wind engineering. The economic viability and political appeal of wind power is on the increase, making this text a timely addition to the literature. It was developed to complement the increasing number of renewable/wind energy courses now available, it includes end-of-chapter tutorial sections, and it combines both academic and industrial experience. Its coverage spans every aspect of wind energy engineering

Biomass power cost and optimum plant size in western Canada

Abstract: The power cost and optimum plant size for power plants using three biomass fuels in western Canada were determined. The three fuels are biomass from agricultural residues (grain straw), whole boreal forest, and forest harvest residues from existing lumber and pulp operations (limbs and tops). Forest harvest residues have the smallest economic size, 137 MW, and the highest power cost, $63.00 MWh −1 (Year 2000 US$). The optimum size for agricultural residues is 450 MW (the largest single biomass unit judged feasible in this study), and the power cost is $50.30 MWh −1 . If a larger biomass boiler could be built, the optimum project size for straw would be 628 MW . Whole forest harvesting has an optimum size of 900 MW (two maximum sized units), and a power cost of $47.16 MWh −1 without nutrient replacement. However, power cost versus size from whole forest is essentially flat from 450 MW ($47.76 MWh −1 ) to 3150 MW ($48.86 MWh −1 ) , so the optimum size is better thought of as a wide range. None of these projects are economic today, but could become so with a greenhouse gas credit. All biomass cases show some flatness in the profile of power cost vs. plant capacity. This occurs because the reduction in capital cost per unit capacity with increasing capacity is offset by increasing biomass transportation cost as the area from which biomass is drawn increases. This in turn means that smaller than optimum plants can be built with only a minor cost penalty. Both the yield of biomass per unit area and the location of the biomass have an impact on power cost and optimum size. Agricultural and forest harvest residues are transported over existing road networks, whereas the whole forest harvest requires new roads and has a location remote from existing transmission lines. Nutrient replacement in the whole forest case would make power from the forest comparable in cost to power from straw.

Wind Turbine Operation in Electric Power Systems

Abstract: The first € price and the £ and $ price are net prices, subject to local VAT. Prices indicated with * include VAT for books; the €(D) includes 7% for Germany, the €(A) includes 10% for Austria. Prices indicated with ** include VAT for electronic products; 19% for Germany, 20% for Austria. All prices exclusive of carriage charges. Prices and other details are subject to change without notice. All errors and omissions excepted.

Offshore wind turbine

Abstract: A wind energy conversion system optimized for offshore application. Each wind turbine includes a semi-submersible hull with ballast weight that is moveable to increase the system's stability. Each wind turbine has an array of rotors distributed on a tower to distribute weight and loads and to improve power production performance where windshear is high. As much of the equipment associated with each rotor as possible is located at the base of the tower to lower the metacentric height. The equipment that may be emplaced at the bottom of the tower could include a power electronic converter, a DC to AC converter, or the entire generator with a mechanical linkage transmitting power from each rotor to the base of the tower. Rather than transmitting electrical power back to shore, it is contemplated to create energy intensive hydrogen-based products at the base of the wind turbine. Alternatively, there could be a central factory ship that utilizes the power produced by a plurality of wind turbines to create a hydrogen-based fuel. The hydrogen-based fuel is transported to land and sold into existing markets as a value-added 'green' product.

Green power: What is it and where can we find it?

Abstract: The interest in commercial green power in the developed world is about 25 years old, starting in the mid-1970s after the first oil shock. Electricity derived from any renewable energy source is considered "green" because of the negligible impact on greenhouse gas emissions. In terms of commercial energy, this list currently includes hydro, wind, biomass, geothermal, and solar. In the 1970s and 1980s, the interest in green power was driven by the goal of replacing fossil fuels to minimize the dependence on oil. Now there is a broader goal: to minimize the emission of CO/sub 2/ (the most common global warming gas) that results from the burning of fossil fuels. This article discusses the market potential for renewable resources, green power in the mainstream electric utilities, and the following renewable resources: hydroelectric power, wind power; biomass; solar thermal power; solar photovoltaics; and geothermal power.

Modelica open library for power plant simulation: design and experimental validation

Abstract: The open Modelica library ThermoPower for the simulation of thermal power plants is presented, by illustrating the modelling principles and the main features of the developed models. The library has been validated against experimental data coming from a laboratory drum boiler, and the main results are shown in the paper. The library, plant model, and validation data are publicly available through the Web.

Is the answer blowing in the wind

Abstract: Wind power is the most rapidly growing technology for renewable power generation. However, fundamental differences exist between conventional thermal, hydro, and nuclear generation and wind power. These differences are reflected in the specific interaction of wind turbines with the power system. Further, there are differences between the various wind turbine types, which also affect their system interaction. In this article, first the current status and the technology of wind power are briefly discussed. The general working principles are explained and the different wind turbine types are described. Then, the differences between wind power and conventional power generation are highlighted as well as their consequences for interaction with the power system, both locally and on a system level.

Electric power plant with adjustable array of fuel cell systems

Abstract: An electric power plant includes an array of fuel cell systems. The fuel cell systems are electrically couplable in series and/or parallel combinations to provide a variety of output powers, output current and/or output voltages. The fuel cell systems are “hot swappable” and redundant fuel cell systems may automatically replace faulty fuel cell systems to maintain output power, current and/or voltage.

Communication and control network for distributed power resource units

Abstract: Methods and systems are disclosed for managing a plurality of power resource assets from a central control center, operating the plurality of power resource assets in an automated fashion as a single power plant.

Optimal operations management and network planning of a district heating system with a combined heat and power plant

Abstract: District heating plants are becoming more common in European cities. These systems make it possible to furnish users with warm water while locating the production plants in the outskirts having the double benefit of lowering the impact of pollution on the center of the city and achieving better conversion performances. In order to amortize the costs throughout the year, the system often includes a combined heat and power (CHP) plant, to exploit the energy during the summer as well, when the demand for warm water decreases. A linear programming model for the optimal resource management of such a plant is presented and some results for a real case are reported. A distribution network design problem is also addressed and solved by means of mixed integer linear programming.

An Updated Point Design for Heavy Ion Fusion

Abstract: An updated, self-consistent point design for a heavy ion fusion (HIF) power plant based on an induction linac driver, indirect-drive targets, and a thick liquid wall chamber has been completed. Conservative parameters were selected to allow each design area to meet its functional requirements in a robust manner, and thus this design is referred to as the Robust Point Design (RPD-2002). This paper provides a top-level summary of the major characteristics and design parameters for the target, driver, final focus magnet layout and shielding, chamber, beam propagation to the target, and overall power plant.

Electricity from bagasse in Zimbabwe

Abstract: 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 (MWe) since 1985, when two thermal units totaling 440 MW e were completed at Hwange. The effective capacity is 1.75 GW e . The current plan is to increase capacity by installing 600 MW e 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 MW e bagasse (moisturized fiber 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.

Fuel cell powered UPS systems: design considerations

Abstract: In this paper a 1 kVA fuel cell powered line-interactive UPS system employing modular (fuel cell and power converter) blocks is introduced. Two commercially available PEMFC (25-39 V, 500 W) modules along with suitable DC/DC and DC/AC power electronic converter modules are employed. A supercapacitor module is also employed to compensate for the instantaneous power fluctuations and overcome the slow dynamics of the fuel processor such as reformers. Further energy stored in the supercapacitor is also utilized to handle a momentary overload such as 200% for a short duration. Due to the absence of batteries, the system satisfies the demand for an environmentally friendly clean source of energy. A complete design example illustrating the amount of hydrogen storage required for 1 hr power outage, and sizing of supercapacitors for transient load demand is presented for a 1 kVA UPS. Simulation and experimental results show the validity and feasibility of the 1 kVA fuel cell power plant.

Life cycle inventory for electric energy system in Brazil

Abstract: The goal of this paper is to present the modeling of life cycle inventory (LCI) for electric energy production and delivery in Brazil for the reference year 2000 by application of ISO 14040. Site specific data along with sector production data have been combined to construct an energy production model, which has been applied to emissions estimation. Background-data of all the inputs and outputs from the system have been inventoried as follows: gross electric energy generation, installed nameplate capacity, flooded area, losses, emissions to air / water, process waste, used fuel, efficiency and land use. In Brazil, electricity is supplied to the various regions by an interconnected system composed of 418 electric companies, consisting of 389 hydraulic power plants and 29 thermal power stations. Due to this enormous number of companies, life cycle inventory for the electricity grid mix was developed on the basis of the following hierarchy: information received from companies (15), data from Brazilian Industrial Information System for the energy Sector (SIESE) and Brazilian Ministries. The functional unit was 1,000 MJ (278 kWh) of electricity distributed to electricity users. The main emissions from power stations, as well as those from fuel production, were investigated. The hydraulic process was not considered emission-free — a model was proposed where emissions of renewable CO2 and CH4 (hydro) are attributed to the degradation of plants submerged in the reservoir areas. The production and distribution of 1,000 MJ of electricity by the interconnected system in Brazil requires approx. 1,600 MJ of process energy, 230 kg of water (evaporated at thermal plants), 116 m3 of waterflow through the turbines, 13 kg of coal, 5 kg of biotic reserves and 0.25 m2a of land use. Emissions related to the 1,000 MJ electricity distributed were 18 kg of non-renewable CO2,17 kg of renewable CO2, 540 g of CH4, 575 g of NOx, 116 g of SO2,149 g of CO, among others. Thermal power stations are the main contributors to these emissions, except for CH4 and renewable CO2 being contributions from coal production and hydraulic power plants, respectively. In spite of considering the emissions of CO2 and CH4 by the submerged plants in the flooded area of dams in hydropower stations, it has been shown that electric energy production is a very clean process due to the characteristics of the electric energy production in Brazil — 93.5% hydraulic. This means 1,000 MJ of delivered electricity produces approx. 34 kg of CO2, being 18 kg (53%) of non-renewable CO2 emitted by fossil fuel burning at thermal power plants that participate with only 6.5% of the electric energy production in Brazil. This was the first tentative model to express electric energy generation and distribution in Brazil in terms of LCA. In future, a more detailed study should be made in order to improve this model. A complementary paper will be produced in which future scenarios of the Brazilian electricity grid mix will be discussed, including possible alternatives to minimize the environmental impacts of hydropower plants.

Optimal boiler control through real-time monitoring of unburned carbon in fly ash by laser-induced breakdown spectroscopy.

Abstract: A laser-induced breakdown spectroscopy (LIBS) technique has been applied for detection of unburned carbon in fly ash, and an automated LIBS unit has been developed and applied in a 1000-MW pulverized-coal-fired power plant for real-time measurement, specifically of unburned carbon in fly ash. Good agreement was found between measurement results from the LIBS method and those from the conventional method (Japanese Industrial Standard 8815), with a standard deviation of 0.27%. This result confirms that the measurement of unburned carbon in fly ash by use of LIBS is sufficiently accurate for boiler control. Measurements taken by this apparatus were also integrated into a boiler-control system with the objective of achieving optimal and stable combustion. By control of the rotating speed of a mill rotary separator relative to measured unburned-carbon content, it has been demonstrated that boiler control is possible in an optimized manner by use of the value of the unburned-carbon content of fly ash.

Steady as she blows [wind power, energy storage]

Abstract: Power electronics and exotic energy storage devices are making wind power steady enough to compete with conventional electricity sources. Systems based on advanced power electronics and energy storage devices are massaging and managing power flows from wind turbines, enabling them to contribute to electricity grids without putting those grids at risk. Not only are the technologies making wind power more palatable to grid operators, they are even making it possible for engineers to finally harness wind energy's tremendous potential in wind-swept, remote locales. This article discusses the power electronic and energy storage technologies used in wind power.

Multi-Application Small Light Water Reactor Final Report

Abstract: The Multi-Application Small Light Water Reactor (MASLWR) project was conducted under the auspices of the Nuclear Energy Research Initiative (NERI) of the U.S. Department of Energy (DOE). The primary project objectives were to develop the conceptual design for a safe and economic small, natural circulation light water reactor, to address the economic and safety attributes of the concept, and to demonstrate the technical feasibility by testing in an integral test facility. This report presents the results of the project. After an initial exploratory and evolutionary process, as documented in the October 2000 report, the project focused on developing a modular reactor design that consists of a self-contained assembly with a reactor vessel, steam generators, and containment. These modular units would be manufactured at a single centralized facility, transported by rail, road, and/or ship, and installed as a series of self-contained units. This approach also allows for staged construction of an NPP and ''pull and replace'' refueling and maintenance during each five-year refueling cycle. Development of the baseline design concept has been sufficiently completed to determine that it complies with the safety requirements and criteria, and satisfies the major goals already noted. The more significant features of the baseline single-unit design concept include: (1) Thermal Power--150 MWt; (2) Net Electrical Output--35 MWe; (3) Steam Generator Type--Vertical, helical tubes; (4) Fuel UO{sub 2}, 8% enriched; (5) Refueling Intervals--5 years; (6) Life-Cycle--60 years. The economic performance was assessed by designing a power plant with an electric generation capacity in the range of current and advanced evolutionary systems. This approach allows for direct comparison of economic performance and forms a basis for further evaluation, economic and technical, of the proposed design and for the design evolution towards a more cost competitive concept. Applications such as cogeneration, water desalination or district heating were not addressed directly in the economic analyses since these depend more on local conditions, demand and economy and can not be easily generalized. Current economic performance experience and available cost data were used. The preliminary cost estimate, based on a concept that could be deployed in less than a decade, is: (1) Net Electrical Output--1050 MWe; (2) Net Station Efficiency--23%; (3) Number of Power Units--30; (4) Nominal Plant Capacity Factor--95%; (5) Total capital cost--$1241/kWe; and (6) Total busbar cost--3.4 cents/kWh. The project includes a testing program that has been conducted at Oregon State University (OSU). The test facility is a 1/3-height and 1/254.7 volume scaled design that will operate at full system pressure and temperature, and will be capable of operation at 600 kW. The design and construction of the facility have been completed. Testing is scheduled to begin in October 2002. The MASLWR conceptual design is simple, safe, and economical. It operates at NSSS parameters much lower than for a typical PWR plant, and has a much simplified power generation system. The individual reactor modules can be operated as on/off units, thereby limiting operational transients to startup and shutdown. In addition, a plant can be built in increments that match demand increases. The ''pull and replace'' concept offers automation of refueling and maintenance activities. Performing refueling in a single location improves proliferation resistance and eliminates the threat of diversion. Design certification based on testing is simplified because of the relatively low cost of a full-scale prototype facility. The overall conclusion is that while the efficiency of the power generation unit is much lower (23% versus 30%), the reduction in capital cost due to simplification of design more than makes up for the increased cost of nuclear fuel. The design concept complies with the safety requirements and criteria. It also satisfies the goals for modularity, standard plant design, certification before construction, construction schedule, refueling schedule, operation and maintenance, long plant life-cycle, and economics.