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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

On Techno-economic Evaluation of Wind-based DG

Albadi, Mohammed 21 January 2010 (has links)
The growing interest in small-scale electricity generation located near customers, known as Distributed Generation (DG), is driven primarily by emerging technologies, environmental regulations and concerns, electricity market restructuring, and growing customer demand for increased quality and reliability of the electricity supply. Wind turbines are one of the renewable DG technologies that have become an important source of electricity in many parts of the world. Wind power can be used in many places to provide a viable solution to rising demand, energy security and independence, and climate change mitigation. This research aims broadly at facilitating the integration of wind-based DG without jeopardizing the system’s economics and reliability. To achieve this goal, the thesis tackles wind power from three perspectives: those of the policy maker, the investor, and the system operator. Generally, the economic viability of a project is determined within the framework of relevant policies. Therefore, these policies influence the decisions of potential investors in wind power. From this perspective, chapters 3 and 4 investigate the influence of policies on the economic viability of wind-based DG projects. In chapter 3, the role of Ontario’s taxation and incentive policies in the economic viability of wind-based DG projects is investigated. In this study, the effects of provincial income taxes, capital cost allowances, property taxes, and relevant federal incentives are considered. Net Present Value (NPV) and Internal Rate of Return (IRR) for different scenarios are used to assess the project’s viability under the Ontario Standard Offer Program (SOP) for wind power. In chapter 4, the thesis proposes the use of wind power as a source of electricity in a new city being developed in the Duqm area of Oman, where no policies supporting renewable energy exist. The study shows that the cost of electricity produced by wind turbines is higher than that of the existing generation system, due to the subsidized prices of domestically available natural gas. However, given high international natural gas prices, the country’s long-term Liquefied Natural Gas (LNG) export obligations, and the expansion of natural gas-based industries, investments in wind power in Duqm can be justified. A feed-in tariff and capital cost allowance policies are recommended to facilitate investments in this sector. From a wind-based DG investor’s perspective, the optimal selection of wind turbines can make wind power more economical, as illustrated in chapters 5 and 6. In chapter 5, the thesis presents a new generic model for Capacity Factor (CF) estimation using wind speed characteristics at any site and the power performance curve parameters of any pitch-regulated wind turbine. Compared to the existing model, the proposed formulation is simpler and results in more accurate CF estimation. CF models can be used by wind-based DG investors for optimal turbine-site matching applications. However, in chapter 6, the thesis demonstrates that using CF models as the sole basis for turbine-site matching applications tends to produce results that are biased towards higher towers but do not include the associated costs. Therefore, a novel formulation for the turbine-site matching problem, based on a modified CF formulation that does include turbine tower height, is introduced in chapter 6. The proposed universal Turbine-Site Matching Index (TSMI) also includes the effects of turbine rated power and tower height on the initial capital cost of wind turbines. Chapter 7 tackles wind power from a power system operator’s perspective. Despite wind power benefits, the effects of its intermittent nature on power systems need to be carefully examined as penetration levels increase. In this chapter, the thesis investigates the effects of different temporal wind profiles on the scheduling costs of thermal generation units. Two profiles are considered: synoptic-dominated and diurnal-dominated variations of aggregated wind power. To simulate wind profile impacts, a linear mixed-integer unit commitment problem is formulated in a GAMS environment. The uncertainty associated with wind power is represented using a chance constrained formulation. The simulation results illustrate the significant impacts of different wind profiles on fuel saving benefits, startup costs, and wind power curtailments. In addition, the results demonstrate the importance of the wide geographical dispersion of wind power production facilities to minimize the impacts of network constraints on the value of the harvested wind energy and the amount of curtailed energy.
2

On Techno-economic Evaluation of Wind-based DG

Albadi, Mohammed 21 January 2010 (has links)
The growing interest in small-scale electricity generation located near customers, known as Distributed Generation (DG), is driven primarily by emerging technologies, environmental regulations and concerns, electricity market restructuring, and growing customer demand for increased quality and reliability of the electricity supply. Wind turbines are one of the renewable DG technologies that have become an important source of electricity in many parts of the world. Wind power can be used in many places to provide a viable solution to rising demand, energy security and independence, and climate change mitigation. This research aims broadly at facilitating the integration of wind-based DG without jeopardizing the system’s economics and reliability. To achieve this goal, the thesis tackles wind power from three perspectives: those of the policy maker, the investor, and the system operator. Generally, the economic viability of a project is determined within the framework of relevant policies. Therefore, these policies influence the decisions of potential investors in wind power. From this perspective, chapters 3 and 4 investigate the influence of policies on the economic viability of wind-based DG projects. In chapter 3, the role of Ontario’s taxation and incentive policies in the economic viability of wind-based DG projects is investigated. In this study, the effects of provincial income taxes, capital cost allowances, property taxes, and relevant federal incentives are considered. Net Present Value (NPV) and Internal Rate of Return (IRR) for different scenarios are used to assess the project’s viability under the Ontario Standard Offer Program (SOP) for wind power. In chapter 4, the thesis proposes the use of wind power as a source of electricity in a new city being developed in the Duqm area of Oman, where no policies supporting renewable energy exist. The study shows that the cost of electricity produced by wind turbines is higher than that of the existing generation system, due to the subsidized prices of domestically available natural gas. However, given high international natural gas prices, the country’s long-term Liquefied Natural Gas (LNG) export obligations, and the expansion of natural gas-based industries, investments in wind power in Duqm can be justified. A feed-in tariff and capital cost allowance policies are recommended to facilitate investments in this sector. From a wind-based DG investor’s perspective, the optimal selection of wind turbines can make wind power more economical, as illustrated in chapters 5 and 6. In chapter 5, the thesis presents a new generic model for Capacity Factor (CF) estimation using wind speed characteristics at any site and the power performance curve parameters of any pitch-regulated wind turbine. Compared to the existing model, the proposed formulation is simpler and results in more accurate CF estimation. CF models can be used by wind-based DG investors for optimal turbine-site matching applications. However, in chapter 6, the thesis demonstrates that using CF models as the sole basis for turbine-site matching applications tends to produce results that are biased towards higher towers but do not include the associated costs. Therefore, a novel formulation for the turbine-site matching problem, based on a modified CF formulation that does include turbine tower height, is introduced in chapter 6. The proposed universal Turbine-Site Matching Index (TSMI) also includes the effects of turbine rated power and tower height on the initial capital cost of wind turbines. Chapter 7 tackles wind power from a power system operator’s perspective. Despite wind power benefits, the effects of its intermittent nature on power systems need to be carefully examined as penetration levels increase. In this chapter, the thesis investigates the effects of different temporal wind profiles on the scheduling costs of thermal generation units. Two profiles are considered: synoptic-dominated and diurnal-dominated variations of aggregated wind power. To simulate wind profile impacts, a linear mixed-integer unit commitment problem is formulated in a GAMS environment. The uncertainty associated with wind power is represented using a chance constrained formulation. The simulation results illustrate the significant impacts of different wind profiles on fuel saving benefits, startup costs, and wind power curtailments. In addition, the results demonstrate the importance of the wide geographical dispersion of wind power production facilities to minimize the impacts of network constraints on the value of the harvested wind energy and the amount of curtailed energy.
3

CO2 capture from oxy-fuel combustion power plants

Hu, Yukun January 2011 (has links)
To mitigate the global greenhouse gases (GHGs) emissions, carbon dioxide (CO2) capture and storage (CCS) has the potential to play a significant role for reaching mitigation target. Oxy-fuel combustion is a promising technology for CO2 capture in power plants. Advantages compared to CCS with the conventional combustion technology are: high combustion efficiency, flue gas volume reduction, low fuel consumption, near zero CO2 emission, and less nitrogen oxides (NOx) formation can be reached simultaneously by using the oxy-fuel combustion technology. However, knowledge gaps relating to large scale coal based and natural gas based power plants with CO2 capture still exist, such as combustors and boilers operating at higher temperatures and design of CO2 turbines and compressors. To apply the oxy-fuel combustion technology on power plants, much work is focused on the fundamental and feasibility study regarding combustion characterization, process and system analysis, and economic evaluation etc. Further studies from system perspective point of view are highlighted, such as the impact of operating conditions on system performance and on advanced cycle integrated with oxy-fuel combustion for CO2 capture. In this thesis, the characterization for flue gas recycle (FGR) was theoretically derived based on mass balance of combustion reactions, and system modeling was conducted by using a process simulator, Aspen Plus. Important parameters such as FGR rate and ratio, flue gas composition, and electrical efficiency etc. were analyzed and discussed based on different operational conditions. An advanced evaporative gas turbine (EvGT) cycle with oxy-fuel combustion for CO2 capture was also studied. Based on economic indicators such as specific investment cost (SIC), cost of electricity (COE), and cost of CO2avoidance (COA), economic performance was evaluated and compared among various system configurations. The system configurations include an EvGT cycle power plant without CO2 capture, an EvGT cycle power plant with chemical absorption for CO2 capture, and a combined cycle power plant. The study shows that FGR ratio is of importance, which has impact not only on heat transfer but also on mass transfer in the oxy-coal combustion process. Significant reduction in the amount of flue gas can be achieved due to the flue gas recycling, particularly for the system with more prior upstream recycle options. Although the recycle options have almost no effect on FGR ratio, flue gas flow rate, and system electrical efficiency, FGR options have significant effects on flue gas compositions, especially the concentrations of CO2 and H2O, and heat exchanger duties. In addition, oxygen purity and water/gas ratio, respectively, have an optimum value for an EvGT cycle power plant with oxy-fuel combustion. Oxygen purity of 97 mol% and water/gas ratio of 0.133 can be considered as the optimum values for the studied system. For optional operating conditions of flue gas recycling, the exhaust gas recycled after condensing (dry recycle) results in about 5 percentage points higher electrical efficiency and about 45 % more cooling water consumption comparing with the exhaust gas recycled before condensing (wet recycle). The direct costs of EvGT cycle with oxy-fuel combustion are a little higher than the direct costs of EvGT cycle with chemical absorption. However, as plant size is larger than 60 MW, even though the EvGT cycle with oxy-fuel combustion has a higher COE than the EvGT cycle with chemical absorption, the EvGT cycle with oxy-fuel combustion has a lower COA. Further, compared with others studies of natural gas combined cycle (NGCC), the EvGT system has a lower COE and COA than the NGCC system no matter which CO2 capture technology is integrated. / QC 20111123
4

Analýza vlivu zateplení na cenu bytové jednotky v Opavě / Analysis of the influence of insulation on the price of housing units in Opava

Adamus, Aleš January 2013 (has links)
This dissertation analyzes the effect of insulation on the price of housing units in Opava city. In the theoretical part of the dissertation deals with the subject of appraisement, the energy intensity of buildings and technical-economic evaluation. In the practical part sets the prices of selected housing units by direct comparison, the comparative method by regulation and yield value. It assesses whether the possible range in the valuation regulations (5%) reflects the fact that the recognized building insulated in accordance to the current legislation. It detects the energy nature of a apartment building in which they are placed selected apartments. The goal is to determine a price increase of housing units due to insulation and evaluates the appropriateness and inappropriateness of buying from the investor's perspective.

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