Showing papers on "Base load power plant published in 2004"

Hybrid fuel cell strategies for clean power generation

Abstract: A hybrid power system consists of a combination of two or more power generation technologies to make best use of their operating characteristics and to obtain efficiencies higher than that could be obtained from a single power source. Since fuel cells directly convert fuel and an oxidant into electricity through an electrochemical process, they produce very low emissions and have higher operating efficiencies. Hence, combining fuel cells with other sources, the efficiency of the combined system can be further increased or extend the duration of the available power to the load as a backup power. In this paper, different types of fuel-cell hybrid systems and their applications are presented. An analysis of the combined cycle operation of a solid oxide fuel cell (SOFC)-microturbine is presented. A strategy for combining the thermophotovoltaic power generation unit and SOFC to obtain the hybrid power system that would have higher efficiency is proposed. The hybrid operation of wind power and solar power system with proton exchange membrane fuel cell is also presented.

Localized reactive power markets using the concept of voltage control areas

Abstract: In this paper, we present the design of a localized competitive market for reactive power ancillary services at the level of individual voltage-control areas. The concept of electrical distance has been used to identify the different voltage-control areas within a power system. The proposed reactive power market is settled on uniform price auction, using a modified optimal power-flow model. Uniform prices for various components of reactive power service are obtained for each voltage-control area. In the study cases described in the paper, we examine whether such a localized reactive power market is more desirable than a common system-wide reactive power market.

System and methods for maintaining power usage within a set allocation

Abstract: An electric power management system includes a monitor for the total power usage of a facility that monitors a history of power consumption during a set time interval of a distribution system having at least one electric load. Predictions of available power are generated through out the time interval by comparing the history of power consumption to a set allocation. Available power predictions are transmitted to the at least one electric load. The at least one load control receives the power capability predictions and controls the energy usage of the at least one electric load such that the total energy usage of the facility does not exceed the set allocation.

Executive overview: energy storage options for a sustainable energy future

Abstract: Sustainability of electric power systems will involve very large use of renewable energy sources for power production. Some of these sources, e.g. wind and solar, have a characteristic stochastic behaviour, which makes their output power production difficult to predict and have high power output fluctuations. Energy storage devices will be needed at different locations in the power system, to level the mismatch between renewable power generators and consumption and/or to store the surplus of power from renewable sources for later use during nongeneration time periods or low power generation time periods. This presentation will give an overview of different storage technologies and how they can be used in a sustainable power system.

System operation with a significant wind power penetration

Abstract: With increasing levels of wind generation capacity on electricity systems, system operators will need to adapt their system operation policy to facilitate the efficient and cost effective integration of wind power. This paper illustrate the relative merits of adopting different system operational approaches on a system with significant wind power capacity. The impact on conventional generation, reserve levels and emissions are assessed and the implications are discussed. The illustrations show that an operational approach, which incorporates wind forecast information, while considering an increased need for reserve due to wind power, results in a more efficient integration of the wind capacity.

Method and system for control of turbogenerator power and temperature

Abstract: A power controller controls the turbine of a turbine powered generating system regardless of the load on the system to maximize the efficiency of the turbine and maintains the turbine at a substantially constant temperature during a system load change by using an energy storage device to provide power to the load while the turbine is changing speed to meet the new load demand.

Simulation of wind speed forecast errors for operation planning of multiarea power systems

Abstract: The amount of wind power has increased significantly over the last years. When the share of wind power increases it is necessary to consider the produced power in the daily operation planning of the power system. The first step is then to use forecasts of wind power. But the forecasts of wind power are in reality rather uncertain, so reserves have to be kept for unforecasted wind speed changes. But still an economical good solution is of large interest, and the consequence of this is to use stochastic optimization. To be able to do this it is necessary to have a view, so called scenarios, of possible outcomes of wind power. The aim of this paper is to provide a method that can simulate possible outcomes of wind speeds based on available forecasts. The method is based on the assumption that wind speed forecasts are available in several regions and the forecast errors in different regions are correlated. The developed method is based on multidimensional ARMA series.

Study on load frequency control using redox flow batteries

Abstract: Rechargeable batteries such as redox flow, which are not aged by frequent charging and discharging, have a quick response equivalent to SMES and outstanding function during overload. The battery efficiency increases when the cycle period of charging/discharging becomes shorter. In addition to leveling load, the battery is advantageous for secondary control in the power system and maintenance of power quality of distributed power resources. In this paper, we study the control performance of RF battery systems in its application to LFC. Using dynamic simulation, we show that the LFC capacity of RF battery systems is ten times that of fossil power systems due to quick response characteristics.

Short-term hydro scheduling in a liberalized power system

Abstract: The paper addresses the challenges of short-term hydropower scheduling in a liberalized power system. Hydropower systems may have quite complex topologies with many cascaded reservoirs/power plants in the same river system. The reservoirs may have very different storage capacity with significant water travel time that makes the decisions coupled between several time steps. In other words, the decisions in one time interval have strong impact on what's possible to do in later time steps. In systems where some of the reservoirs have significant storage capacity, the use of the hydropower resources short-term will be coupled with the long-term strategic decisions. It is not feasible to have the short-term decisions within the same model as the long-term decisions because modeling of uncertainty is important. The problem is decomposed into a planning hierarchy where the long/mid-term models provide boundary conditions for the short-term models. The major items of this paper are: challenges and possible solutions in hydro system modeling, a flexible coupling principle between short-term and mid-term scheduling, strategies for bidding in a spot market.

Hybrid clean-energy power-supply framework

Abstract: A hybrid clean-energy power-supply framework integrates a fuel cell, solar cell, and wind energy, applies a max power tracking rule, raises the output power of a solar cell and wind energy to supply a power load and transfer the surplus electrical energy to a water-electrolyzing apparatus for producing hydrogen and oxygen, and provides a fuel for a fuel cell power generating system. Furthermore, the present invention utilizes features of each clean-energy power generating system, depends on the powerful calculation capacity of a central processing unit to monitor and dispatch each power generation and supply system, and thus ensures the reliability of supply power and reduces the power generation cost. Such a framework can selectively grid-connect with the utility power or run as a stand-alone power supply system and has a mechanism for preventing the island effect.

Electric power trading support system

Abstract: An electric power trading support system includes a demand prediction unit, a demand prediction error evaluation unit, a demand predicted value upward adjustment ratio (quantity) setting unit, a private power generation/power purchase ratio (quantities) setting unit, an optimization unit for evaluating optimum values of the demand predicted value upward adjustment ratio (quantity) and the self power generation/power purchase ratio (quantities) based on costs, and a display unit for displaying the optimum values evaluated by the optimization unit, maximizing profit to an electric power retailer by minimizing the cost for power generation and power purchase when the electric power retailer sells electric power by use of a private power generator and backup electric power purchased from an electric power company.

Basic design aspects of micro hydro power plant and its potential development in Malaysia

Abstract: Hydro power plants convert potential energy of water into electricity. It is a clean source of energy .The water after generating electrical power is available for irrigation and other purposes. The first use of moving water to produce electricity was a waterwheel on the Fox River in Wisconsin in 1882. Hydropower continued to play a major role in the expansion of electrical service early in this century around the world. Hydroelectric power plants generate from few kW to thousands of MW. They are classified as micro hydro power plants for the generating capacity less than 100 KW. Hydroelectric power plants are much more reliable and efficient as a renewable and clean source than the fossil fuel power plants. This resulted in upgrading of small to medium sized hydroelectric generating stations wherever there was an adequate supply of moving water and a need for electricity. As electricity demand soared in the middle of this century and the efficiency of coal and oil fueled power plants increased, small hydro plants fell out of favor. Mega projects of hydro power plants were developed. The majority of these power plants involved large dams, which flooded big areas of land to provide water storage and therefore a constant supply of electricity. In recent years, the environmental impacts of such large hydro projects are being identified as a cause for concern. It is becoming increasingly difficult for developers to build new dams because of opposition from environmentalists and people living on the land to be flooded. Therefore the need has arisen to go for the small scale hydro electric power plants in the range of mini and micro hydro power plants. There are no micro hydro power plants in Malaysia and the smallest category of hydro power plants in Malaysia is mini hydro with a capacity between 500 kW to 100 kW. This paper discusses the conceptual design and development of a micro hydro power plant .The overall estimation and calculation of a 50 kW power plant has been carried out. Software is also developed using MATLAB to calculate the total head, discharge rate, type of turbine for the micro hydro power plants, once the capacity is known.

Wind power generation evaluation system and prediction control service system for wind power generator

Abstract: A wind power generation evaluation system includes: a laser aerovane 100-300 that measures, with laser, the direction and velocity of wind at a distance from a wind power generator connected to an electric power system to predict the direction and velocity of wind at the wind power generator; a second aerovane 500 that measures them at the wind power generator; a wind power generation output calculation unit 400a that integrates a difference between power outputs calculated based on measurements by the laser aerovane and the second aerovane while referring to a windmill performance curve indicating output power characteristic of the wind power generator regarding wind velocity, to obtain a difference between the amounts of generated power; and an additional value calculation unit 400b that calculates additional value of an influence on the environment based on the difference between the amounts of generated power obtained by the calculation unit 400a.

Don't let the sun go down on PV [photovoltaic systems]

Abstract: In response to global issues for the generation and delivery of electrical power, photovoltaic (PV) and other renewable energy technologies are gaining acceptance as a way of maintaining and improving living standards without harming the environment PV could help mitigate energy crises by reducing peak demand and securing the delivery of power in congested locations by decentralizing the power generation This article shows the challenges of photovoltaic in restructured power systems PV technologies could provide more secure mode of operation for power system during peak load hours when the systems are constrained and locational marginal prices are high

Static and dynamic under-frequency load shedding: a comparison

Abstract: Safe operation of a power system requires that system frequency is kept within a specified range. When the generation is insufficient due to disturbances, the frequency might fall under the minimum allowable value which may lead to system blackout if not properly counteracted. This frequency decline may be corrected by shedding certain amount of load so that the system is back into balanced state. In this paper several under-frequency load shedding schemes are reviewed. Comparison are made between static scheme which shed a fixed, predetermined amount of load at each stage and a dynamic system which shed the load by taking into account the size of the disturbance and the voltage and frequency characteristics. Simulations were done on a five buses power system to obtain the amount of load shed, minimum under-frequency, number of stages and completion time. Results from the dynamic scheme appear to give a better frequency recovery.

Method and apparatus for providing load dispatch and pollution control optimization

Abstract: An economic dispatch program allocates a load demand and an emission allowance of a power generation system among various power plants to determine the operational set-points and the pollution control set-points of each of the various power plants in a manner that minimizes the total operating cost for the power generation system, including the pollution control cost. The economic dispatch program uses the pollution control set-points and the load set-points of the various power plants as decision variables and takes into consideration the pollution control costs of the various power plants in allocating the load demand. During operation, the economic dispatch program takes into consideration the pollution credits available to the various power plants in allocating the load demand and pollution control level to determine the optimal operating solution for the power plants.

Wind Power Impacts on Electric Power System Operating Costs: Summary and Perspective on Work to Date; Preprint

Abstract: Electric utility system planners and operators are concerned that variations in wind plant output may increase the operating costs of the system. This concern arises because the system must maintain an instantaneous balance between the aggregate demand for electric power and the total power generated by all power plants feeding the system. This is a highly sophisticated task that utility operators and automatic controls perform routinely, based on well-known operating characteristics for conventional power plants and a great deal of experience accumulated over many years. System operators are concerned that variations in wind plant output will force the conventional power plants to provide compensating variations to maintain system balance, thus causing the conventional power plants to deviate from operating points chosen to minimize the total cost of operating the system. The operators' concerns are compounded by the fact that conventional power plants are generally under their control and thus are dispatchable, whereas wind plants are controlled instead by nature. Although these are valid concerns, the key issue is not whether a system with a significant amount of wind capacity can be operated reliably, but rather to what extent the system operating costs are increased by the variability of the wind.

The power of power.

Abstract: Creative Commons would like to acknowledge the many contributions of sta, consultants, sponsors, and supporters responsible for producing !\"#$ %&'#($&)$*+#,. A very special thanks goes to the organizations, artists, and creators who not only share their work with CC licenses, but shared their time and insights to be proled in this book. Visit http://thepowerofopen.org to download a digital version of !\"#$ %&'#($&)$*+#n or to nd out how to order print copies. The double C in a circle, the words and logotype \" Creative Commons, \" and the Creative Commons license buttons are trademarks of Creative Commons. For more information, see http://creativecommons.org/policies. CREDITS The world has experienced an explosion of openness. From individual artists opening their creations for input from others, to governments requiring publicly funded works be available to the public, both the spirit and practice of sharing is gaining momentum and producing results. Creative Commons began providing licenses for the open sharing of content only a decade ago. Now more than 400 million CC-licensed works are available on the Internet, from music and photos, to research ndings and entire college courses. Creative Commons created the legal and technical infrastructure that allows eective sharing of knowledge, art and data by individuals, organizations and governments. More importantly, millions of creators took advantage of that infrastructure to share work that enriches the global commons for all humanity. !\"#$%&'#($&)$*+#, collects the stories of those creators. Some are like ProPublica, a Pulitzer Prize-winning investigative news organization that uses CC while partnering with the world's largest media companies. Others like nomadic lmmaker Vincent Moon use CC licensing as an essential element of a lifestyle of openness in pursuit of creativity. The breadth of uses is as great as the creativity of the individuals and organizations choosing to open their content, art and ideas to the rest of the world. As we look ahead, the eld of openness is approaching a critical mass of adoption that could result in sharing becoming a default standard for the many works that were previously made available only under the all-rights-reserved framework. Even more exciting is the potential increase in global welfare from the use of Creative Commons' tools and the increasing relevance of openness to the discourse of culture, education and innovation policy. We hope that !\"#$%&'#($&)$*+#, inspires you to examine and embrace the practice of open licensing so that your contributions to the global intellectual commons can provide …

Grid stabilising system

Abstract: The invention provides control of an electric load receiving power from a grid. The frequency of the grid is detected and used to determine a stress level on the grid. A high frequency detection is indicative of too little a load for the electrical power being supplied to the grid and, therefore, a low stress condition. A high stress condition may exist if there is too much load for the power being supplied to the grid. Adjustment of the power consumption of the load is prevented if the high and/or low stress states is determined. If a critical high or low stress condition is determined, the load is either prevented from consuming power completely or the load is set to a maximum power consumption state, respectively. The benefits of the invention are increased if the device is combined with a load controller which operates to control power consumption based on grid frequency and a variable, which, for the particular load, is to be kept within controlled limits.

An investigation on the reactive power support service needs of power producers

Abstract: Reactive power is an important system support service in the current power market. Power producers or generators have the opportunity to offer this service to make a profit. Given the fact that a generator needs reactive power to transmit its own active power, however, it is possible that certain generators cannot support a system even if they are generating reactive power. This paper investigates such a phenomenon and proposes a method to determine the minimum amount of reactive power (Q/sub min/) required for a given generator. If a generator cannot supply this minimum amount, it actually draws reactive power support from the system to facilitate its own active power selling activity. Compensation to a generator's reactive power output should be made only to the amount that is above the Q/sub min/ amount. The proposed ideas are illustrated with simple systems in this paper and tested on a real-life power system. The test results verified the validity of the proposed concept and method.

Bounding active power generation of a wind-hydro power plant

Abstract: In the usual operation, wind park production is strongly dependent on the instantaneously available wind power. When energy storage is accessible, the wind park operation can be improved, aiming to a better exploitation of the available wind power resource. The present work proposes an optimization approach to determinate the most probable range of the output production, to be used in the definition of production profiles that will help the participation of wind power in the market. Two production profiles strategies were analyzed and compared. The forecasted wind power is represented as a stochastic variable and real wind power Portuguese conditions have been used in the evaluation of the model.

Strategic self-dispatch considering ramping costs in deregulated power markets

Abstract: Ramp rates of generators are generally specified within elastic range of the strength of the shaft to safeguard the rotor from fatigue. These limits can, however, be exceeded, albeit at the risk of reducing the rotor life. Such effects on the rotor life can be compensated by incorporating appropriate ramping costs. Power demand and power price in deregulated power markets have shown a tendency of sudden wide excursions over short intervals of time. The ability to respond to such fast change in demand and price can be quite rewarding. This provides the motivation to utilize the ramping rates beyond traditional elastic limits. This paper studies the strategic use of ramping rates beyond elastic limits in a power producer's self-dispatch in a power market with price and demand volatility. A set of ramping processes has been developed from ramping-cost versus ramping time relationships to derive the total operation cost including ramping costs for various levels of ramping rates exceeding elastic limits. A thorough theoretical analysis has been conducted for the selection of the optimal ramping process under different conditions. A numerical example is presented to highlight the potential benefits from the optimal use of these ramping processes. It is seen that the benefit from the strategic use of ramp rates beyond elastic limits not only depends on the high price in the power market but also on the initial loading of the generator which limits the capacity available for dispatch.

Supply management system for electric power

Abstract: PROBLEM TO BE SOLVED: To provide a supply management system for electric power that contributes to the improvement in the asset value of a multiple dwelling house, by maintaining a contract class by preventing demand from exceeding a contract level, and to provide various kinds of services through the effective use of the system. SOLUTION: This supply management system 1000 for electric power is provided with an information-related system that collects the data of electricity energy of each resident room from each watthour meter installed in the rooms divided in plural numbers in a building, and calculates power rate divided proportionally according to consumed electric power and a power-related system that makes power supply switching control to receive power supply from an auxiliary power source if demand is predicted to exceed the contract level. The power-related system performs the power supply switching control in such a way that the demand is kept within the contract level to maintain a basic charge at a low rate. The information-related system calculates a power rate by meter according to the consumed electric power for each room to achieve a low power rate. COPYRIGHT: (C)2006,JPO&NCIPI

Method for operating a wind turbine during a disturbance in the grid

Abstract: The invention relates to a method for operating a wind turbine. In first operating conditions in a normal mode, said wind turbine delivers a first output to a connected electricity grid, said first output being proportional to the wind speed. The wind turbine is controlled in such a way that it remains connected to the electricity grid during a disturbance, delivering a second output to the connected electricity grid, said output being lower than the first. Once the disturbance has ceased, a third output of short duration is delivered to the connected electricity grid in the first operating conditions, said third output being significantly higher than the first.

Home-use fuel cell system

Abstract: During a time zone where power demand is smaller than an average value of the entire power demands of homes, an excess portion obtained by subtracting power demand from a base power portion supplied by a PEFC (1) is charged in a capacitor (7) and a lead storage battery (8); and during a time zone where power demand is larger than an average value, a peak power portion exceeding this average value is discharged from the capacitor (7) and the lead storage battery (8); thereby enabling the system to meet a day’s home-use demand with minimum equipment by effectively using surplus power. Accordingly, energy efficiency and cost efficiency can be enhanced without wasting energy.

Active cooling to reduce leakage power

Abstract: Leakage power consumed by an integrated circuit is estimated as the difference between total power consumption and a nominal expected power consumption. Leakage power is reduced by cooling the integrated circuit in an active cooling system. By expending power in the active cooling system, the integrated circuit is cooled and the total power consumption is decreased. When the decrease in total power consumption is greater than the power expended in the cooling system, an overall power savings is achieved.

Domestic power system

Abstract: PROBLEM TO BE SOLVED: To satisfy a rational relationship between power selling and power purchasing, and to rationally control a storage water heater in a domestic power system including the storage water heater and a private power generator and constituted so as to sell power to a commercial power supply. SOLUTION: If power Egen generated by the private power generator exceeds the total Ecsm of the quantity of power used by domestic electrical appliances and the power Egen possibly has excess power, the minimum thermal storage is increased from the first minimum thermal storage value Kmin_L to the second minimum thermal storage value Kmin_H higher than it. If a thermal storage K_real within a hot water storage tank is smaller than the second minimum thermal storage value Kmin_H, a heat pump unit is operated by the private power generator 21, and water is additionally heated within the hot water tank until a second target thermal storage Kaim_2 smaller and better than a first target thermal storage Kaim is attained. COPYRIGHT: (C)2006,JPO&NCIPI

Fiscal Interactions and the Costs of Controlling Pollution from Electricity

Abstract: This paper quantifies the costs of controlling SO2, carbon, and NOx emissions from power generation, accounting for interactions between environmental policies and the broader fiscal system. We distinguish a dirty technology (coal) that satisfies baseload demand and a clean technology (gas) that is used during peak periods, and we distinguish sectors with and without regulated prices. Estimated emissions control costs are substantially lower than in previous models of fiscal interactions that assume a single, constant returns technology and competitive pricing. The results are reasonably robust to alternative scenarios, such as full price deregulation and market power in the deregulated sector.