Showing papers on "Base load power plant published in 2012"
TL;DR: In this paper, a review of several energy storage technologies for wind power applications is presented, where the main objectives of the article are the introduction of the operating principles, as well as the presentation of the main characteristics of ESS technologies suitable for stationary applications, and the definition and discussion of potential ESS applications in wind power according to an extensive literature review.
Abstract: Due to the stochastic nature of wind, electric power generated by wind turbines is highly erratic and may affect both the power quality and the planning of power systems. Energy Storage Systems (ESSs) may play an important role in wind power applications by controlling wind power plant output and providing ancillary services to the power system and therefore, enabling an increased penetration of wind power in the system. This article deals with the review of several energy storage technologies for wind power applications. The main objectives of the article are the introduction of the operating principles, as well as the presentation of the main characteristics of energy storage technologies suitable for stationary applications, and the definition and discussion of potential ESS applications in wind power, according to an extensive literature review.
1,268 citations
TL;DR: In this article, the authors present methods used in recent wind integration analyses and operating practice, with key results that compare different methods or data, and conclude that wind variability need not be seen as a contingency event.
Abstract: Power systems with high wind penetration experience increased variability and uncertainty, such that determination of the required additional operating reserve is attracting a significant amount of attention and research. This paper presents methods used in recent wind integration analyses and operating practice, with key results that compare different methods or data. Wind integration analysis over the past several years has shown that wind variability need not be seen as a contingency event. The impact of wind will be seen in the reserves for nonevent operation (normal operation dealing with deviations from schedules). Wind power will also result in some events of larger variability and large forecast errors that could be categorized as slow events. The level of operating reserve that is induced by wind is not constant during all hours of the year, so that dynamic allocation of reserves will reduce the amount of reserves needed in the system for most hours. The paper concludes with recent emerging trends.
263 citations
TL;DR: In this article, the authors developed scenarios for 100% renewable generation to meet current electricity demand in the five Australian states and one territory spanned by the National Electricity Market (NEM).
252 citations
TL;DR: The algorithm finds near-optimal schedules even when AMI messages are lost, which can happen in the presence of malfunctions or noise in the communications network.
Abstract: This paper deals with load control in a multiple-residence setup. The utility company adopts a cost function representing the cost of providing energy to end-users. Each residential end-user has a base load, two types of adjustable loads, and possibly a storage device. The first load type must consume a specified amount of energy over the scheduling horizon, but the consumption can be adjusted across different slots. The second type does not entail a total energy requirement, but operation away from a user-specified level results in user dissatisfaction. The research issue amounts to minimizing the electricity provider cost plus the total user dissatisfaction, subject to the individual constraints of the loads. The problem can be solved by a distributed subgradient method. The utility company and the end-users exchange information through the Advanced Metering Infrastructure (AMI)-a two-way communication network-in order to converge to the optimal amount of electricity production and the optimal power consumption schedule. The algorithm finds near-optimal schedules even when AMI messages are lost, which can happen in the presence of malfunctions or noise in the communications network. The algorithm amounts to a subgradient iteration with outdated Lagrange multipliers, for which convergence results of wide scope are established.
246 citations
TL;DR: In this paper, the authors argue that the transition from ac to dc is not only necessary but inevitable and that the majority of the load base is natively dc at some point soon.
Abstract: We are on the cusp of a great technology transition in power distribution from ac to dc at the edge of the grid Data centers are merely one of the first industries to embrace the coming tide The transition on the customer side of the meter is on the order of what happened over the last 40 years with personal computers, the Internet, and cell phones The predominant use of power electronics in almost everything we buy new today makes them natively dc devices As a society, we could be more efficient and sustainable if we were to skip the last ac-to-dc conversion At some point soon, when the majority of the load base is natively dc, we reach a tipping point where ac and hot power converter “bricks” on everything are no longer sustainable Add to this distributed generation, distributed energy storage, and renewable carbon-free power sources that prefer dc, and one can conclude that the transition is not only necessary but inevitable
237 citations
TL;DR: In this paper, the role of grid extensions for the market effects of variable renewable energy (VRE) generation from wind and sun is examined in Europe, where the authors derive cost-optimal macroscopic transmission grid extensions.
207 citations
01 Nov 2012
TL;DR: In this article, a low-complexity algorithm called Demand Response with Energy Storage Management (DR-ESM) is proposed to find an optimal control policy for deciding how much load to consume and how much power to purchase from/sell to the power grid.
Abstract: We consider the problem of optimal demand response with energy storage management for a power consuming entity. The entity's objective is to find an optimal control policy for deciding how much load to consume, how much power to purchase from/sell to the power grid, and how to use the finite capacity energy storage device and renewable energy, so as to minimize his average cost, being the disutility due to load-shedding and cost for purchasing power. Due to the coupling effect of the finite size energy storage, such problems are challenging and are typically tackled using dynamic programming, which is often complex in computation and requires substantial statistical information of the system dynamics. We instead develop a low-complexity algorithm called Demand Response with Energy Storage Management (DR-ESM). DR-ESM does not require any statistical knowledge of the system dynamics, including the renewable energy and the power prices. It only requires the entity to solve a small convex optimization program with 6 variables and 6 linear constraints every time for decision making. We prove that DR-ESM is able to achieve near-optimal performance and explicitly compute the required energy storage size.
154 citations
TL;DR: It is shown that a policy to encourage CCS at new NGCC plants via an emission tax or carbon price requires (at 95% confidence) a price of at least $125/t CO(2) to ensure NGCC-CCS is cheaper than a plant without CCS.
Abstract: This paper examines the cost of CO(2) capture and storage (CCS) for natural gas combined cycle (NGCC) power plants. Existing studies employ a broad range of assumptions and lack a consistent costing method. This study takes a more systematic approach to analyze plants with an amine-based postcombustion CCS system with 90% CO(2) capture. We employ sensitivity analyses together with a probabilistic analysis to quantify costs for plants with and without CCS under uncertainty or variability in key parameters. Results for new baseload plants indicate a likely increase in levelized cost of electricity (LCOE) of $20-32/MWh (constant 2007$) or $22-40/MWh in current dollars. A risk premium for plants with CCS increases these ranges to $23-39/MWh and $25-46/MWh, respectively. Based on current cost estimates, our analysis further shows that a policy to encourage CCS at new NGCC plants via an emission tax or carbon price requires (at 95% confidence) a price of at least $125/t CO(2) to ensure NGCC-CCS is cheaper than a plant without CCS. Higher costs are found for nonbaseload plants and CCS retrofits.
145 citations
22 Jul 2012
TL;DR: In this paper, the role of operational flexibility for the transition of existing power systems, many of them based on fossil fuels, towards power systems effectively accommodating high shares of variable renewable energy sources (RES) has been widely recognized.
Abstract: Operational flexibility is an important property of electric power systems. The term flexibility is widely used in the context of power systems although at times without a proper definition. The role of operational flexibility for the transition of existing power systems, many of them based on fossil fuels, towards power systems effectively accommodating high shares of variable Renewable Energy Sources (RES) has been widely recognized. Availability of sufficient operational flexibility is a necessary precondition for the grid integration of large shares of power in-feed from variable RES, for example wind power and photovoltaics (PV). The paper analyzes the role of operational flexibility in power systems. Necessary flexibility metrics for categorizing different types of operational flexibility are discussed. A new methodology for assessing the technically available operational flexibility is presented. Qualitative insights are derived, notably regarding the limits of RES integration for a given power system with its specific flexibility properties. An extensive simulation study is performed, assessing the role that operational flexibility has for the mitigation of challenges, namely curtailment, arising from high shares of variable RES in-feed.
121 citations
TL;DR: In this article, the authors proposed a method that can be applied to hourly whole-house electrical energy data to partially disaggregate total household electricity use into five load categories/parameters (base load, activity load, heating season gradient, cooling season gradient and lowest external temperature at which air-conditioning is used).
118 citations
TL;DR: In this article, the authors make a contribution to the evaluation of biomass power plants based on dedicated energy crops and evaluate the strategic, environmental and economic interest of the project under the present RES support schemes.
TL;DR: In this paper, a combination of wind, solar, and nuclear energy is explored to provide a large fraction of a system's electricity, assuming the use of thermal energy storage that would allow nuclear power to provide load following and cycling duty while operating at a constant reactor power output.
TL;DR: The proposed micro-wind energy conversion system with battery energy storage is used to exchange the controllable real and reactive power in the grid and to maintain the power quality norms as per International Electro-Technical Commission IEC-61400-21 at the point of common coupling.
Abstract: In the micro-grid network, it is especially difficult to support the critical load without uninterrupted power supply. The proposed micro-wind energy conversion system with battery energy storage is used to exchange the controllable real and reactive power in the grid and to maintain the power quality norms as per International Electro-Technical Commission IEC-61400-21 at the point of common coupling. The generated micro-wind power can be extracted under varying wind speed and can be stored in the batteries at low power demand hours. In this scheme, inverter control is executed with hysteresis current control mode to achieve the faster dynamic switchover for the support of critical load. The combination of battery storage with micro-wind energy generation system (μ WEGS), which will synthesize the output waveform by injecting or absorbing reactive power and enable the real power flow required by the load. The system reduces the burden on the conventional source and utilizes μ WEGS and battery storage power under critical load constraints. The system provides rapid response to support the critical loads. The scheme can also be operated as a stand-alone system in case of grid failure like a uninterrupted power supply. The system is simulated in MATLAB/SIMULINK and results are presented.
TL;DR: In this paper, a solar chimney power plant (SCPP) is proposed to be built as the first national SCPP in central regions of Iran, where solar radiation and global insolation are much better than other areas.
Abstract: A solar chimney power plant (SCPP) is proposed to be built as the first national SCPP in central regions of Iran. Studies of DLR MED-CSP project show that Iran can be a part of the Mediterranean solar power generation chain in 2050 to provide electrical power demand of Europe. High direct solar radiation and available desert lands in Iran are factors to encourage the full development of solar power plants like solar chimney power plants for the thermal and electrical productions of energy for various uses. The interested region is the central region of Iran where solar radiation and global insolation are much better than other areas. However, to evaluate SCPP performance and power generation throughout Iran, 12 different areas across the country are considered. The obtained results clear that solar chimney power plants can produce from 10 to 28 MWh/month of electrical power. This power production is sufficient for the needs of the isolated areas and can even used to feed the grid.
TL;DR: In this paper, the authors propose a methodology for long-term power transmission expansion planning that incorporates the costs associated with the operation of wind power plants, where the authors model the transmission expansion problem as a mixed-integer linear program in which the variability of the wind resource, the impact of wind-power operation in the system security and the impact on wind power operation in reserve market are incorporated.
Abstract: Power generation from renewable sources has greatly increased in the last decade. Accordingly, the planning of power system expansions must incorporate the special features of these types of energy sources. Long-term power transmission expansion planning usually does not take these differences among energy sources into account because of the long period considered. However, modelling the special features of renewable sources may influence the optimal transmission plan. In this study, the authors propose a methodology for long-term power transmission expansion planning that incorporates the costs associated with the operation of wind power plants. In particular, the authors model the transmission expansion planning problem as a mixed-integer linear program in which the variability of the wind resource, the impact of wind power operation in the system security and the impact of wind power operation in the reserve market are incorporated. The authors illustrate the methodology using a 34-node version of the main Chilean network.
01 Dec 2012
TL;DR: This paper studies the problem of optimally placing large-scale energy storage in power grids with both conventional and wind generation using a semidefinite relaxation of AC optimal power flow.
Abstract: This paper studies the problem of optimally placing large-scale energy storage in power grids with both conventional and wind generation. The solution technique for this infinite horizon problem assumes cyclic demand and generation profiles using a semidefinite relaxation of AC optimal power flow. Changes in storage allocation in the network are studied as a function of total storage budget and transmission line-flow constraints. These questions are investigated using an IEEE benchmark system with various generation portfolios.
TL;DR: The modern power grid is one of the most complex engineering machines in existence as mentioned in this paper, and the U.S. National Academy of Engineering has voted to recognize the grid as the supreme engineering achievement of the 20th century.
Abstract: The modern power grid is one of the most complex engineering machines in existence. Its millions of components comprise the entire electricity supply chain, from point of generation to the end consumer. Each of these pieces must work together, reliably, 24 hours a day, seven days a week, to power our homes and businesses. In 2001, the U.S. National Academy of Engineering voted to recognize the grid as the supreme engineering achievement of the 20th century. Making matters more complex is the reality that grid conditions are continually changing every second, every minute, and every hour of the day. Changes in demand for electricity necessitate instantaneous changes in electricity production; consequently, voltages, currents, and power flows are dynamically changing at all times across the electricity supply chain.
TL;DR: In this paper, a new perspective of the constraints on the effective utilization of wind power in the Northeast China Grid is provided, which includes grid structure, wind source structure, power source structure and market structure.
Abstract: Even though China's wind power industry has experienced a rapid growth since the beginning of this century, the utilization of wind power is still worrisome. In 2010, about 30% of China's total installed capacity could not get access to the grid. And about 10% of China's total wind power generation was curtailed. The problem of wind power curtailment is more prominent in Northeast-China region. The main particularity of Northeast China Grid is as follows: during the long heating period in winter, combined heat and power thermal plants need to modify the turbine generator's output to meet the heating demand and thus the thermal power peak regulation capacity is reduced, as a result the barriers of wind power consumption are increased. This paper provides a new perspective of the constraints on the effective utilization of wind power in the Northeast China Grid. We argue that there are two categories of constrained factors: structural factor and operational factor. The former includes grid structure, wind source structure, power source structure, and market structure. The latter includes power price mechanism, dispatch mode arrangement, wind power integration codes, and wind power forecast. At last, we make policy recommendations: promote the coordination between wind farm investment and grid construction, strengthen interprovincial power trade mechanism, implement flexible pricing mechanisms as well as improve current dispatch mode, etc.
27 Mar 2012
TL;DR: In this article, a new method is proposed to quantify the system reserve levels, which considers the probability distribution of forecast errors of wind and load, as well as generator forced outage rate by using the Expectation of Demand Not Served (EDNS) as evaluation index.
Abstract: With increasing wind power penetration in many power systems, the requirement of spinning reserve is becoming an important issue, which is directly related to the reliability and economy of the system. To analysis it, there are many uncertainties, such as load forecast error, wind forecast error and generator outage rate, which relate system reserve level to the reliability of it. In this paper, a new method is proposed to quantify the system reserve levels. The method considers the probability distribution of forecast errors of wind and load, as well as generator forced outage rate by using the Expectation of Demand Not Served (EDNS) as evaluation index. The proposed method is then applied to a test system. Results illustrate the relationships of uncertainties with the system reserve level.
Book•
30 Sep 2012
TL;DR: The High Temporal Resolution Electricity Market Analysis Model (THEA) as discussed by the authors has been developed for the ERCOT market in Texas and the German power market with its interconnected markets, and the results show significant differences compared to the results when the full spectrum of THEA's capabilities is utilized.
Abstract: As power systems increase in complexity due to higher shares of intermitting RES-E, so increase the requirements for power system modeling.
This thesis shows empirically, with examples from Germany and Texas, that the increasing RES-E share strongly affects current power market operation. The markets further create price signals, which lead to system adaptations in the long-run.
To get an estimate of the adaptation effects, 'The High Temporal Resolution Electricity Market Analysis Model' (THEA) has been developed. In a first application for the ERCOT market in Texas, particular model attributes are tested and compared to some complexity reducing approaches, i.e. the reduction of temporal resolution and the reduction of operational constraints. In both cases, the results show significant differences compared to the results when the full spectrum of THEA's capabilities is utilized. The ERCOT case study additionally shows that the adaptation to RES-E in an isolated, mainly thermal-based power system is quite severe. Market signals which underline this conclusion are the severely reduced value of wind energy, the increasing curtailment and the strong shift towards peak-oriented generating capacities.
The second application of THEA models the German power market with its interconnected markets. This analysis increases the complexity significantly by modeling a well interconnected system, increasing the amount of different RES-E technologies and adding CAES investment options. In order to assess the impact on the different system component's supply, demand and grid infrastructure, specific measures are applied to compare several scenarios. Each scenario represents a policy option, which either reduces or increases the flexibility of the power system. The scenario comparisons capture the effects of a lower RES-E share, a larger baseload capacity fleet, higher interconnector capacities, various RES-E support scheme designs and the capability of RES-E to participate in the reserve power market.
In general, the results show that if the flexibility of one system component is reduced, the flexibility values of other system components increase, which suggests a careful, integrated and long-term oriented policy setting.
TL;DR: In this paper, the authors developed a controller for wind farms to optimize the load and power distribution, which is formulated as an optimization problem and solved using an approximation method, and the optimization problem for the wind farm was modeled as a bilinear control system.
TL;DR: In this article, the authors compare and contrast CCS applied to coal-fired power plants with CSP, and show that CCS is more expensive than existing electricity-generating options, but costs should decrease with large-scale deployment, especially in the case of CSP.
TL;DR: In this paper, the authors developed metrics to evaluate the impact of intermittent renewable generation on the electric load demand that must be balanced by dispatchable generation resources, allowing examination of the general impacts of accommodating high renewable penetration levels.
TL;DR: The emissions model incorporates the effects of both cycling and start-ups of thermal power plants in analyzing emissions from an electric power system with increasing levels of wind power and concludes that as the wind power penetration increases, pollutant emissions decrease overall due to the replacement of fossil fuels.
Abstract: This paper discusses the environmental effects of incorporating wind energy into the electric power system. We present a detailed emissions analysis based on comprehensive modeling of power system operations with unit commitment and economic dispatch for different wind penetration levels. First, by minimizing cost, the unit commitment model decides which thermal power plants will be utilized based on a wind power forecast, and then, the economic dispatch model dictates the level of production for each unit as a function of the realized wind power generation. Finally, knowing the power production from each power plant, the emissions are calculated. The emissions model incorporates the effects of both cycling and start-ups of thermal power plants in analyzing emissions from an electric power system with increasing levels of wind power. Our results for the power system in the state of Illinois show significant emissions effects from increased cycling and particularly start-ups of thermal power plants. However, we conclude that as the wind power penetration increases, pollutant emissions decrease overall due to the replacement of fossil fuels.
01 Oct 2012
TL;DR: It is expected that MPC strategy for Active Demand Side Management (ADSM) can dramatically save energy and improve grid reliability, when there is a high penetration of Renewable Energy Sources (RESs) in the power system.
Abstract: This paper presents a Model Predictive Controller (MPC) for electrical heaters' predictive power consumption including maximizing the use of local generation (e.g. solar power) in an intelligent building. The MPC is based on dynamic power price and weather forecast, considering users' comfort settings to meet an optimization objective such as minimum cost and minimum reference temperature error. It demonstrates that this MPC strategy can realize load shifting, and maximize the PV self-consumption in the residential sector. With this demand side control study, it is expected that MPC strategy for Active Demand Side Management (ADSM) can dramatically save energy and improve grid reliability, when there is a high penetration of Renewable Energy Sources (RESs) in the power system.
TL;DR: The feasibility of integrating solar photovoltaic panels and wind turbines into the grid by also accounting for energy storage is investigated by extending and applying stochastic network calculus to analyze the power supply reliability with various renewable energy configurations.
Abstract: Renewable energy such as solar and wind generation will constitute an important part of the future grid. As the availability of renewable sources may not match the load, energy storage is essential for grid stability. In this paper we investigate the feasibility of integrating solar photovoltaic (PV) panels and wind turbines into the grid by also accounting for energy storage. To deal with the fluctuation in both the power supply and demand, we extend and apply stochastic network calculus to analyze the power supply reliability with various renewable energy configurations. To illustrate the validity of the model, we conduct a case study for the integration of renewable energy sources into the power system of an island off the coast of Southern California. In particular, we asses the power supply reliability in terms of the average Fraction of Time that energy is Not-Served (FTNS).
TL;DR: In this paper, the authors present a procedure aimed at evaluating the extra cost related to flexible operation, and at assisting the management decision about power plants' operation and maintenance scheduling, considering the effects of creep, thermo-mechanical fatigue, welding, corrosion and oxidation.
22 Jul 2012
TL;DR: In this article, a static load model has been developed for a universal input battery charger at the first stage and the second phase of the study considers static voltage stability margins, system losses, the regulatory voltage limits, and the cable flow ratings for appropriate placement of EV fast charging stations in electricity grid.
Abstract: Introduction of the electric vehicle (EV) to the transport sector is greatly anticipated considering numerous environmental and socio-economical benefits. Consideration of their charging impact on electricity networks is of major importance to power system engineers under such circumstances. A number of system studies can be found in the literature describing different aspects of EV charging on power grid. However, scant attention has been paid to the issue of power system stability due to EV charging. Practicality of the power system stability studies is mainly determined by the accuracy of the models used to represent the EV load. However, EV load modeling for system stability studies has not yet been considered in the literature. Hence, for this study, a static load model has been developed for a universal input battery charger at the first stage. The second phase of the study considers static voltage stability margins, system losses, the regulatory voltage limits, and the cable flow ratings for appropriate placement of EV fast charging stations in electricity grid. Further, the maximum allowable charging station capacity at a network point is evaluated based on reliable and stable grid operation.
TL;DR: In this paper, a conditional probabilistic method within a time series model is presented to quantify the risk in wind power commitment during system operation, which is relatively simple to apply, and therefore should be useful to power system operators and wind farm owners to commit an appropriate amount of power in the next hour(s) based on the known initial wind power output.
Abstract: The installation of wind power systems is growing rapidly all over the world mainly due to increased environmental concerns regarding electricity generation and the perceived need to use renewable energy resources. The uncertain and intermittent nature of wind power has led to growing problems in integrating wind power in power systems as the wind power penetration continues to increase. One of the main challenges faced in power system operation with high wind penetration is to maintain the system reliability when committing an appropriate amount of power from a wind farm in the lead time considered. Commitment of wind power is a crucial task, which requires accurate wind power forecasting. Statistical methods employing time series model have been used to predict the short term wind power with reasonable accuracy. The short term (up to 4-6 hours) wind power is dependent upon the initial wind power and the wind site. Any future prediction contains a certain amount of risk. Short term wind power commitment is therefore also dependent upon the acceptable risk criterion, which is a managerial decision. This paper presents a conditional probabilistic method within a time series model to recognize the variability in wind, and to quantify the risk in wind power commitment during system operation. Complex methods that require significant amount of data are not readily applied in practical application. This paper presents a generalized and approximate risk based method that is relatively simple to apply, and therefore, should be useful to power system operators and wind farm owners to commit an appropriate amount of power in the next hour(s) based on the known initial wind power output.
TL;DR: The intelligent integration of wind power into the existing electricity supply system will be an important factor in the future energy supply in many countries, and new methods of balancing supply and demand are necessary.
Abstract: The intelligent integration of wind power into the existing electricity supply system will be an important factor in the future energy supply in many countries. Wind power generation has characteristics that differ from those of conventional power generation. It is weather dependent in that it relies on wind availability. With the increasing amount of intermittent wind power generation, power systems encounter more and more short-term, unpredicted power variations. In the power system, supply and demand must be equal at all times. Thus, as levels of wind penetration into the electricity system increase, new methods of balancing supply and demand are necessary.