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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.
51

Low Carbon Policy and Technology in the Power Sector: Evaluating Economic and Environmental Effects

Oates, David Luke 01 February 2015 (has links)
In this thesis, I present four research papers related by their focus on environmental and economic effects of low-carbon policies and technologies in electric power. The papers address a number of issues related to the operation and design of CCS-equipped plants with solvent storage and bypass, the effect of Renewable Portfolio Standards (RPS) on cycling of coal-fired power plants, and the EPA’s proposed CO2 emissions rule for existing power plants. In Chapter 2, I present results from a study of the design and operation of power plants equipped with CCS with flue gas bypass and solvent storage. I considered whether flue gas bypass and solvent storage could be used to increase the profitability of plants with CCS. Using a pricetaker profit maximization model, I evaluated the increase in NPV at a pulverized coal (PC) plant with an amine-based capture system, a PC plant with an ammonia-based capture system, and a natural gas combined-cycle plant with an amine-based capture system when these plants were equipped with an optimally sized solvent storage vessel and regenerator. I found that while flue gas bypass and solvent storage increased profitability at low CO2 prices, they ceased to do so at CO2 prices high enough for the overall plant to become NPV-positive. In Chapter 3, I present results from a Unit Commitment and Economic Dispatch model of the PJM West power system. I quantify the increase in cycling of coal-fired power plants that results when complying with a 20% RPS using wind power, accounting for cycling costs not usually included in power plant bids. I find that while additional cycling does increase cycling-related production costs and emissions of CO2, SO2, and NOX, these increases are small compared to the overall reductions in production costs and air emissions that occur with high levels of wind. In proposing its existing power plant CO2 emissions standard, the Environmental Protection Agency determined that significant energy efficiency would be available to aid in compliance. In Chapter 4, I use an expanded version of the model of Chapter 3 to evaluate compliance with the standard with and without this energy efficiency, as well as under several other scenarios. I find that emissions of CO2, SO2, and NOX are relatively insensitive to the amount of energy efficiency available, but that production costs increase significantly when complying without efficiency. In complying with the EPA’s proposed existing power plant CO2 emissions standard, states will have the choice of whether to comply individually or in cooperation with other states, as well as the choice of whether to comply with a rate-based standard or a mass-based standard. In Chapter 5, I present results from a linear dispatch model of the power system in the continental U.S. I find that cooperative compliance reduces total costs, but that certain states will prefer not to cooperate. I also find that compliance with a mass-based standard increases electricity prices by a larger margin than does compliance with a rate-based standard, with implications for the distribution of surplus changes between producers and consumers.
52

INTEGRATING WIND GENERATED ELECTRICITY WITH SPACE HEATING AND STORAGE BATTERIES

Muralidhar, Anirudh 20 December 2010 (has links)
The world faces two major energy-related challenges: reducing greenhouse-gas emissions and improving energy security. Wind-electricity, a clean and environmentally sustainable energy source, appears promising. However, its intermittency is problematic when used as a supply for on-demand electricity. Wind-electricity can be used for space heating when combined with thermal-storage systems; although its intermittency can result in periods of excess electricity. To reduce the excess, this thesis proposes using wind-electricity for thermal-storage and electric-vehicles. Four charging procedures are designed and developed. Data from an eastern Canadian wind-farm is used to demonstrate the procedures. The results are compared and discussed in terms of the supply of wind-electricity and its ability to meet the energy requirements of these services. Depending on the procedure, wind-electricity displaced between 20 and 26 GWh of energy previously required for space-heating and transportation, demonstrating that wind-electricity, with intermittently-chargeable loads using storage, is a solution to the intermittency problem.
53

Comparison of Simultaneous Soil Profile N2O Concentration and Surface N2O Flux Measurements Overwinter and at Spring Thaw in an Agricultural Soil

Risk, Neil 28 May 2012 (has links)
A field experiment was carried out in Ontario, Canada to compare independently measured soil N2O profile concentration and surface N2O flux measurements overwinter and at spring thaw, to estimate the soil N2O content accumulation overwinter, and to estimate the magnitude of the contribution of the physical release of trapped N2O to surface fluxes at spring thaw. Gas samples at various depths were taken and N2O concentrations determined, soil profile gaseous N2O content was calculated by estimating the air-filled pore-space from soil condition measurements, and soil aqueous N2O content was calculated using liquid water content measurements and applying Henry’s Law. Soil N2O content was found to reach a maximum of ~25 mg N2O m-2, and by comparing changes in soil N2O content to surface fluxes measured using the micrometeorological flux-gradient technique, the physical release of previously produced N2O was estimated to contribute up to 47% of spring thaw N2O surface fluxes.
54

Municipal perspectives on greenhouse gas reductions : exploring Strathcona County

Seabrook, Leah 15 June 2010 (has links)
This thesis considers perspectives on municipal greenhouse gas emission reductions. It is timely study as it is one point of entry to analyzing emissions and contemplates the degree of local responsibility, as well as the barriers and possible solutions to creating action. By using a case study approach, Strathcona County was examined in its real-life context to determine the outlook at the local scale. Attention to varying government action plans, as well as scientific research was examined to verify relevance of municipal action. Using survey and interview methods, perspectives from key decision makers were compared and contrasted. The results indicated that there is a concentration at the municipal level on actions that will directly or indirectly benefit climate change. A multi-governance angle, as well as institutionalizing the concept into the organization and community will create progress. Solutions focusing on land use planning, transportation and community energy are emerging. This study demonstrates the value of municipal action as an essential element to achieving long term, cost effective and successful reductions, and recognizes that it is a supplement rather than an alternative to provincial and national plans.
55

Evaluating the Impact of Climate Change Mitigation Strategies on Water Distribution System Design and Optimization

MacLeod, Stephanie Patricia 27 August 2010 (has links)
In response to growing environmental concerns, policy makers in Canada have been developing climate change mitigation strategies that will enable Canada to meet medium and long-term greenhouse gas (GHG) emission reduction targets. The water industry is energy- and carbon-intensive, thus the magnitude and long-term uncertainty of proposed carbon mitigation policies could have implications for water distribution system capital planning decisions that are made today. The intent of this thesis was to examine the implications of discount rate and carbon price uncertainty on cost, energy use and GHG emissions in the design/optimization of the Amherstview water distribution system in Loyalist Township, Ontario, Canada. A non-dominated sorting genetic algorithm is coupled with the hydraulic solver EPANET2 in a single-objective optimization approach to identify network expansion designs that minimize total cost as the sum of: i) capital cost of installing new and parallel pipes and of cleaning and lining existing pipes; ii) operation cost of electricity for pumping water; and iii) carbon cost levied on electricity used for pumping water. The Amherstview system was optimized for a range of discount rates and carbon prices reflective of possible climate change mitigation strategies in Canada over the next 50 years. The problem formulation framework was developed according to a “real-world” municipal approach to water distribution system design and expansion. Decision variables such as pipe sizes are restricted to “real-world” commercially-available pipe diameters and parameter values are chosen according to engineering judgment and best-estimates. Parameter uncertainty is characterized by sensitivity analysis rather than the more computationally-demanding and data-intensive Monte Carlo simulation method. The impact of pipe material selection on energy use and GHG emissions was investigated for polyvinyl chloride and cement-mortar lined ductile iron pipes. Results from this first-ever study indicate that the discount rate and carbon prices investigated had no significant influence on energy use and GHG emissions in the Amherstview system. Pipe material selection was also found to minimally affect the amount of GHG emitted in the Amherstview system. / Thesis (Master, Civil Engineering) -- Queen's University, 2010-08-26 15:01:27.174
56

Implementation and Evaluation of Spatiotemporal Prediction Algorithms and Prediction of Spatially Distributed Greenhouse Gas Inventories

Rodway, James EA Unknown Date
No description available.
57

Development of Greenhouse Gas Mitigation Options for Alberta’s Energy Sector

Subramanyam, Veena Unknown Date
No description available.
58

Spatial variation of soil methane and nitrous oxide emissions in subarctic environments of Churchill, Manitoba

Churchill, Jacqueline A. 07 June 2007 (has links)
Global warming, associated with elevated levels of greenhouse gases is expected to alter hydrologic regimes, permafrost extent and vegetation composition in the Hudson Bay Lowlands (HBL). Greenhouse gas (respiration, CH4 and N2O; GHG) emissions and soil gas concentrations were determined over the growing seasons of 2005 and 2006 from numerous habitats within three dominate ecosystems within the HBL, a polygonized-peat plateau, northern fringe boreal forest and palsa fen, near Churchill, Manitoba. Nitrous oxide emissions and soil concentrations were near zero however, a trend for very slight production of N2O was observed at dry aerobic sample positions while very slight consumption occurred at very wet sample locations. “Hot-spots” of intense CH4 emissions and soil concentrations occurred in the sedge-dominated areas of high moisture and plant productivity, whereas areas of low moisture and plant productivity resulted in slight CH4 consumption. Of all the ecosystems studied, the palsa fen had the greatest CH4 production, with carbon losses from CH4 occurring at rates of approximately 50 g C m-2 during the growing season. A peat plateau ecosystem site was also used to compare GHG emissions using a similar vegetation type (Cladina stellaris) and under differing soil conditions. Based on the results, slight gradients in soil conditions such as moisture content, peat accumulation and active layer depths altered respiration emissions but did not significantly affect CH4 and N2O fluxes. The differences in GHG emissions were not as great as those between different plant community types, which suggest plant community types could be used to predict GHG emissions in similar environments.
59

Diffusive gas fluxes in neotropical rainforest streams

Skoglund, Björn January 1900 (has links)
Rainforests are of great importance to global carbon cycling, but the importance of deforestation and change in land use is poorly understood due to a lack of studies quantifying the difference in carbon fluxes between original rainforest and agricultural land. Furthermore, the aquatic outgassing of neotropical systems have been proven to have greater impact on global carbon cycling than previously anticipated (Richey et al 2002).In this study we investigated the aquatic concentration and daily diffusive gas flux of CO2 and CH4 from 4 pristine sites and 4 impacted sites, respectively, in 4 streams running along a gradient of anthropological impaction in the Atlantic Rainforest, Brazil. Statistically significant differences between pristine and impacted sites were found in all streams for both CO2 and CH4. On average, the impacted sites were found to be emitting almost three times as much C into the atmosphere as the pristine sites, mainly owing to CO2 emissions (14172±5226 mg C m-2 d-1). Exploring an area of the neotropical carbon cycle that is not yet fully understood, the study draws attention to the significant difference in aquatic outgassing from rivers observed at different impaction levels and highlights the need for further field studies.
60

Economics of greenhouse gas mitigation scenarios in beef production

2014 September 1900 (has links)
Animal agriculture plays a vital role in the provision of food for the world population; however, in the wake of global warming and greenhouse gas (GHG) emissions, the industry has been under scrutiny as one of the net emitters causing global warming. The same scrutiny applies to beef production in western Canada. The objective of this study is to evaluate the economic impact of GHG mitigation practices (GHGMP) for beef operations, and in the process identify economic and environmental sustainable scenarios. This study was an extension to a study by Beauchemin et al (2011) who studied the mitigation of GHG emissions from beef production in western Canada A beef simulation model was developed to measure the impacts of adopting GHGMPs on the profitability of a mixed farm in Vulcan County, Southern Alberta. Feed for the herd was produced on the farm, and calves were born and finished on the farm. Whole farm gross margin was used as a profitability measure of the farm over a period of 9 years, which is a full beef production cycle. Eleven GHGMPs were examined and compared to the baseline scenario. These scenarios were adopted from Beauchemin et al (2011), and included dietary modifications (change in use of forages, use of canola seed, and corn distillers grains, and improvement in quality of forage), and improvement in animal husbandry (increased weaning rates, and increased longevity of breeding stock). Simulation results showed a discounted whole farm gross margin of $11.38 per acre for the baseline scenario. Feed costs accounted for 47.1 percent of total costs of beef production. The change in whole farm gross margin per acre from implementation of different GHGMPs ranged from an increase of 4 percent to a decrease of 5 percent. Six scenarios were identified as ‘win-win’ scenarios as they improved both environment and economics of the farm. The profit of these scenarios ranged from $238.11 to $30.31 per tonne of GHG reductions expressed in carbon dioxide equivalent). The loss from the other scenarios capable of reducing GHG emissions range from $92.06 to $582.46 per tonne GHG reduced. Based on these results, it was concluded that western Canadian beef producers can adopt sustainable GHGMPs without substantial changing the structure of their operations. Scenarios that improved both the environment and the economics of the farm were: Scenario 7: use of corn distillers dried grain (CDDG) in finishing ration; Scenario 4: use of canola seed in finishing ration; Scenario 8: use of CDDG in breeding stock ration; Scenario 10: increased calve weaning rate (85% to 90%); Scenario 5: use of canola seed in breeding stock ration; and Scenario 9 : improved hay for breeding stock.

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