Browsing by Subject "Power plant"
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Item Climate action strategies for the University of Texas at Austin(2010-05) Hernandez, Marinoelle; Eaton, David J.; Walker, Jim H.This report analyzes the current greenhouse gas emissions inventory for The University of Texas at Austin (UT-Austin), reviews the carbon reduction strategies being implemented at UT-Austin and other peer institutions, and offers recommendations for strategies that could reduce greenhouse gas emissions at UT-Austin in the future.Item Reconfigurable control in electric utility power plants(2012-12) Do, Khoa Dang; Masada, Glenn Y.; Fernandez, Benito R; Edgar, Thomas F; Grady, Mack W; Chen, DongmeiIn high-level automation industrial processes where maintenance or repair can not be carried out immediately, it is important to design autonomous controllers capable of maintaining the performance, reliability and safety of plants operating under sensor, actuator faults and failures, equipment fouling, feedstock variation. Advanced control strategies such as Active Fault Tolerant Control (AFTC) have been used to accommodate system failures automatically. This research presents an AFTC methodology using model predictive control (MPC) combined with a bank of Kalman Filters. This hybrid fault tolerant control system are testing in a linearized 14-order boiler-turbine unit to deal with sensor faults and actuator faults. When sensor fault occurs, the virtual sensor techniques, which uses both a bank of Kalman Filter and a reconfigured Kalman Filter is applied to estimate the plant state and corrupted sensor value. The reconfigured MPC controller, which has naturally ability in dealing with output and actuator constraints, is equipped with some advanced capabilities such as online parameter tuning mechanism, the stability improvement techniques, the feasibility improvement techniques and reference management technique to handle the plant actuator faults. In case of some specific actuator faults, the MPC controller is restructured to deal with the faults better. The proposed fault tolerant control successfully recovers the system performance in the sensor fault cases and some of the actuator cases. In other fault cases, where the system performance recovery is impossible due to faults, the fault tolerant control degrades the system performance to keep the system stable.Item A spatial decision support framework for web-based, multi-stakeholder engagement : case study of geothermal power project siting in Idaho(2013-12) Noll, Daniel John; Pierce, Suzanne Alise, 1969-; Eaton, David J.; Butler, JohnMulti-criteria decision analysis (MCDA) represents an emerging decision aid tool in the field of natural resource decision-making. This thesis involves research into the application of a multi-criteria spatial decisions support system (MC-SDSS) to support favorability mapping of geothermal resource potential. The main goal is to provide proof of concept of a tool that can facilitate multi-stakeholder engagement during site selection of a potential power generation facility. It presents information on the history and development of spatial decision support systems in the field of environmental and natural resource decision-making, as well as a case study of a MC-SDSS tool--entitled the "Heatseeker" application-- developed and applied to geothermal resource potential in the Eastern Snake River Plain, Idaho. This research was first conducted under a grant from the U.S. Department of Energy National Geothermal Student Competition. The Heatseeker application and supporting infrastructure utilizes a client/server system architecture that provides users with access to spatial and tabular data with low bandwidth requirements. Client-side scripting is used to execute a weighted linear combination (WLC) model and provide users with display and report functionality. Additionally, the tool is optimized for use with a gesture-enabled touch device that serves as a boundary object to facilitate participatory stakeholder engagement. The result of this research is a proof of concept in supporting future MC-SDSS design that can be applied both to geothermal favorability mapping and other natural resource management processes. This work draws upon the research traditions of multiple academic disciplines, including operations research, computer science, cognitive and behavioral psychology, economics, and public policy. The initial development and application of the MC-SDSS tool involved a team of graduate and undergraduate students from geoscience and social science disciplines. Transdisciplinary approaches to problem structuring and decision-making such as this are an increasingly common approach to natural resource issues.Item Sustainable energy systems : the environmental footprints of electricity generation systems : mechanisms for managing electricity, water resources and air quality(2012-08) Alhajeri, Nawaf Salem; Allen, David T.; McDonald-Buller, Elena; Corsi, Richard; Webster, Mort; Webber, MichaelThis thesis examines the response of air pollutant emissions, water use and carbon emissions from electric power supply systems (electrical grids) to market forces and natural and human disruptions. Specifically, the response of electrical grid operation decisions to emissions pricing and other factors, such as drought restrictions, is examined. The grid of the Electricity Reliability Council of Texas (ERCOT) is used as a source of data, and as a spatial and temporal test-bed. Price signals for NOx emissions have the potential to reduce NOx emissions from the ERCOT grid by up to 50%. In addition to lowering NOx, there are co-benefits to introducing NOx prices, including reductions in the emissions of SOx (24.9% to 70.9%), Hg (16.8% to 81.3%) and CO2 (8.7% to 21.1%). Water consumption was also decreased by 4.3% to 8.2%. The costs of redispatching electricity generation to reduce NOx emissions are, in many scenarios, comparable to conventional control costs. Higher CO2 prices produce many of the same changes in electricity generation as increases in NOx prices, but the simultaneous application of NOx and CO2 pricing produces complex effects. Under stress, such as drought induced water scarcity, dispatching decisions have the potential to increase water availability in regions in which drought is a concern. This dispatching had relatively small impacts on total water consumption summed over all regions of the ERCOT grid. However, the dispatching scenarios resulted in net increases in NOx, SOx, and CO2 emissions rates summed over all regions of the grid, particularly in regions that were absorbing the electricity generation that was exported out of the drought impacted regions. The costs of electricity dispatching, per volume of water consumption reduced in the drought impacted region, was generally greater than the cost of implementing dry cooling in the same facilities at high electricity demand levels, but comparable to dry cooling at low to moderate demand levels. Finally, while changes in total emissions can be used as a surrogate for air quality impacts, actual changes in air pollutant concentrations, such as ozone, exhibit complex spatial and temporal patterns in response to redispatching, including the creation of hot spots of elevated concentrations.Item Valuation of an advanced combined cycle power plant and its cost of new entry (CONE) into the ERCOT market(2014-08) Zaborowski, Jeremy Ronald; Webber, Michael E., 1971-The Texas ERCOT market is one of the most open, deregulated electricity markets in the world. This open market brought electricity costs down for Texas residents and businesses, creating a much more competitive economic climate. However, these low prices currently generate insufficient revenue for generators to finance construction of new or replacement generation assets. In the instance of combined cycle advanced natural gas, the Independent Market Monitor 2012 annual report estimated that a plant needed to generate 2.5 times as much as revenue it did in 2012 to incent new generation. This author argues that while the gap is still significant, the continuous changes to the ERCOT market since its inception make an historical examination like that used by the IMM less accurate. New market rules such as price caps or changes in fuel markets through new technologies like hydraulic fracturing create a very different valuation gap than a model based on historical activity alone. This analysis attempts to get a more accurate approximation of the gap through the use of publicly traded futures contracts for natural gas and electricity. Electricity futures reflect market expectations of revenue based on current and future market rules. Gas futures reflect price expectations in light of market changes like fracturing, potential LNG exports, and other changes. Financial positions can be maintained in both markets to give a fixed rate of return. Using this method, one can create a very conservative valuation model that still more accurately reflects market sentiment. This thesis starts with a brief history of ERCOT deregulation from the early 2000s to present in order to clarify for the reader the changes that have taken place in the market. It then demonstrates the futures-valuation model using an advanced combined cycle power plant as an example.