Browsing by Subject "Natural gas"
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Item Open Access BASELINE GROUNDWATER QUALITY TESTING NEEDS IN THE EAGLE FORD SHALE REGION(2012-04-27) Palacios, Virginia E.As the pace of drilling in the Eagle Ford shale increases, so does the potential for groundwater contamination incidents. The goals of this analysis are (1) to determine whether existing baseline groundwater quality data in the Eagle Ford shale region is adequate to provide a comparison to potential future contamination from oil and gas development and (2) to define an appropriate and cost-effective list of parameters that will aid in strategic planning of baseline ground water quality testing in the Eagle Ford shale region for the same goal. First, a list of potential testing parameters is defined using case studies of proposed groundwater contamination. Second, formation water chemistry in the Eagle Ford shale region is compared to groundwater chemistry in the counties of the Eagle Ford shale region to determine which chemical indicators demonstrate potential to consistently detect contamination. Third, statistical power analysis is used as a guideline to decide whether more samples are needed for each testing parameter in each county in the Eagle Ford shale region. Next, known health effects of each testing parameter are described in order to highlight potential pollutants that should be prioritized in a sampling initiative. Finally, testing costs are reported to introduce a perspective about microeconomic choices affecting which stakeholders take responsibility for baseline groundwater quality testing. These tasks led to the findings that some of the most dangerous potential pollutants, including methane, total petroleum hydrocarbons, nitrate, volatile organic compounds, polycyclic aromatic hydrocarbons, alpha particles, beta particles, and gamma radiation, are poorly characterized in the region, if at all. Furthermore, testing these parameters is more expensive than testing less hazardous ones. Water well owners may be unable to afford the expense of testing these parameters. Therefore, a testing initiative facilitated by agencies, industry, or other organizations may be more efficient at establishing a regional baseline for these high priority, expensive tests. As such, the framework and analysis presented here can be used by groundwater managers in the Eagle Ford shale region to develop baseline sampling strategies tailored to specific counties in the region.Item Open Access Changes in U.S. Residential Monthly Energy Use per Capita: 1990-2017(2019) Yang, XiaoxuanResidential energy consumption represents a large share of total end use energy and shows strong correlation with monthly cooling and heating degree days. This study focuses on quantifying temporal change in the relationship between monthly degree days and monthly U.S. residential use of electricity and natural gas for each of the 48 contiguous states from 1990 to 2017. We introduce a single degree day predicator to characterize the non-linear relationship between degree-day and state-level electricity and natural gas use. By looking at trends in three DD-energy use coordinates and curvature from single quadratic fits on a year-by-year and state-by-state basis, we confirm the non-linear relationship between DD and residential energy use and reveal processes that might influence the relationship. We find that residential electricity energy use has become more sensitive to seasonal fluctuations in temperature in most states. While the lowest electricity use per year has risen, natural gas use has fallen since 1990 in most states. We further group the states into 17 classes for electricity use and 21 classes for natural gas use based on combinations of temporal trends in quadratic curve variables. These large groupings for electricity have shown a similar spatial distribution as that of the climate regions defined by the U.S. Department of Energy, reaffirming temperature and humidity as influential factors in the climate-energy relationship. We also compare our results with the household and end uses information from U.S. Energy Information Administration’s Residential Energy Consumption (REC) Surveys and recognize electricity as a growing heating source in all U.S. regions. We further address economic development, energy efficiency of end uses, and building codes as potential trends that affect the relationship between degree day and residential energy use at national, regional and state levels.
Item Open Access Electric Generation Investment in a Time of Natural Gas Price and Carbon Pricing Uncertainty: A Modeling Analysis(2013-04-16) Fitzpatrick, KristopherLow current and forecasted natural gas prices are spurring investment in new gas-fired electric generation in the eastern United States. In both regulated territories and organized electricity markets, natural gas power is beginning to displace significant amounts of retiring coal generation. However, the market price of natural gas has historically been volatile and unpredictable. If gas prices rise substantially from current forecasts in the next two decades, will customers face sharply higher electricity prices? What if a carbon tax accompanies this outcome? This modeling analysis sheds light on these questions by modeling long-term capacity expansion based on current assumptions, and then assessing how economic dispatch in three regions - the Southeast, PJM Interconnection, and ISO New England – will respond to alternate versions of future gas prices and carbon taxes. The results indicate that heavily gas-dependent regions like ISO New England would absorb the imposition of a carbon tax without major electricity price increases, but that it would face substantial price increases with sustained, elevated natural gas prices. The results also suggest that portfolios in the Southeast and PJM will skew more heavily to natural gas generation in the future if investment decisions are made under current conditions and assumptions. If this occurs, these two regions could face sharp electricity price increases with either higher-than-expected natural gas prices or the imposition of a carbon tax.Item Open Access Electric Generation Investment in a Time of Natural Gas Price and Carbon Pricing Uncertainty: A Modeling Analysis(2013-04-16) Fitzpatrick, KristopherLow current and forecasted natural gas prices are spurring investment in new gas-fired electric generation in the eastern United States. In both regulated territories and organized electricity markets, natural gas power is beginning to displace significant amounts of retiring coal generation. However, the market price of natural gas has historically been volatile and unpredictable. If gas prices rise substantially from current forecasts in the next two decades, will customers face sharply higher electricity prices? What if a carbon tax accompanies this outcome? This modeling analysis sheds light on these questions by modeling long-term capacity expansion based on current assumptions, and then assessing how economic dispatch in three regions - the Southeast, PJM Interconnection, and ISO New England – will respond to alternate versions of future gas prices and carbon taxes. The results indicate that heavily gas-dependent regions like ISO New England would absorb the imposition of a carbon tax without major electricity price increases, but that it would face substantial price increases with sustained, elevated natural gas prices. The results also suggest that portfolios in the Southeast and PJM will skew more heavily to natural gas generation in the future if investment decisions are made under current conditions and assumptions. If this occurs, these two regions could face sharp electricity price increases with either higher-than-expected natural gas prices or the imposition of a carbon tax.Item Open Access Energy Storage and Solar for New Peaking Capacity in North Carolina(2019-04-26) Copple, DanielSolar power paired with battery energy storage is increasingly presented as an alternative to traditional natural gas combustion turbine technology for providing power during times of very high demand. This analysis uses hourly simulation of the Duke Energy Carolinas (DEC) electric system to compare the performance and cost of solar plus storage and new simple cycle gas turbine (SCGT) technology. The results show solar plus four-hour battery storage and SGCT perform similarly in addressing the peaking capacity needs of the system. Solar plus four-hour battery storage results in system-wide production cost savings compared to SGCT, but this savings is limited by the SGCT's greater displacement of older, more expensive peaking units and is outweighed in the short-term by higher fixed costs. However, If renewable technology improvements and cost reductions follow historical trends it is possible that new SCGT plants in the DEC system will not maintain high capacity factors and could be economically displaced well before the end of their lifetimes. Utility planners should weigh these risks carefully before committing to a peaking technology choice.Item Open Access Evaluating the Effect of Intermittent Renewables on the Wholesale Electricity Market in Germany(2014-04-24) Adelfio, AndrewFor years, Germany has been a pioneer in the aggressive build out of intermittent renewables (solar and wind). The Energy Concept launched in 2010, in conjunction with previously established federal energy policies, has further enhanced Germany’s ability to reach lofty renewable generation targets via ratepayer surcharges that support feed-in tariffs. However, as the penetration of renewables has increased, wholesale electricity prices have demonstrated a steady decline. Through statistical and market-based analysis, this project 1) quantifies the price decrease that is caused by build out of renewables, 2) examines the market mechanics that result in a price decrease, and 3) evaluates the effect of the price decrease on relevant electricity market participants. Regression analysis indicates that average wholesale electricity prices will experience a decrease of 6.5 €/MWh – 8.5 €/MWh by 2020, solely due to the build out of renewable energy to comply with Energy Concept targets. Based on current electricity demand, this price reduction will result in an annual revenue loss of €2.96 billion – €3.88 billion. Importantly, this revenue loss will not be distributed equally amongst wholesale generators. Generators with higher marginal costs will be affected disproportionately because the frequency with which they can be dispatched profitably will decrease more than for cheaper generators. Specifically, this will hurt natural gas plants, many of which will be phased out due to unfavorable economics. This loss of natural gas plants will 1) present challenges to the grid’s ability to maintain stability while introducing more intermittent renewables and 2) force Germany to remain reliant on carbon-rich coal for electricity. The findings of this study are then applied to other locations that are also pursuing aggressive renewable energy targets.Item Open Access Explaining Merger and Acquisition Premiums in the U.S. Electric and Natural Gas Sectors in a Period of Deregulation from 1990-2012(2013-04-17) Marks, JonathanThis study aims to explain the variance in premiums, or the price paid for a target firm’s equity above its market value, in mergers and acquisitions with natural gas and electric target firms from 1990-2012, a period characterized by industry deregulation. Using a sample of 130 transactions, we test factors that have been shown to be related to premiums in general merger and acquisition studies as well as theorize and test new explanations for premium sizes. We find that premiums offered in our sample of natural gas and electric merger and acquisition transactions are smaller for stock transactions, are positively related to the ratio of acquirer to target firm size, and are negatively related to the percentage of target firm revenue derived from electric operations.Item Open Access Frack to the Future? Closing Oil- and Gas-Related Fractures in the Law of Water Protection(2011-04-29) Pisoni, LauraIn a world of increasing concern about foreign oil imports and climate change, natural gas is expected to become an increasingly important part of the United States’ fuel mix. As conventional natural gas sources are depleted, the gas industry is turning to unconventional sources, including gas-containing shales. Gas shale can only be economically exploited using a method called hydraulic fracturing, which poses potentially grave dangers to surface and groundwater. North Carolina contains commercially viable gas shales. For this reason, the government of North Carolina must protect the state’s water when commercial-scale hydraulic fracturing begins. This masters project examines federal and state water-protection laws. Seven federal statutes were considered—Clean Water Act; Safe Drinking Water Act; National Environmental Policy Act; Resource Conversation and Recovery Act; Toxic Substances Control Act; Emergency Planning and Community Right-to-Know Act; and Comprehensive Environmental Response, Compensation, and Liability Act—along with two North Carolina state-level provisions. The project identifies exemption and exceptions that prevent these statutes from robustly protecting water quality from hydraulic fracturing. The project concludes with three major recommendations for North Carolina. First, the state should enact a statutory moratorium on hydraulic fracturing. Second, the state should reassess and strengthen state water quality laws and regulations. Third, the state should require openness by passing a state-level community right-to-know act.Item Open Access Master Limited Partnerships: Implications for US Energy Infrastructure(2018-04-27) Arnason, Elizabeth; Cagan, AlexandraIn 1981, Apache Corporation created the first Master Limited Partnership (MLP) with the creation of Apache Petroleum Corporation. Since then, the MLP model has served as an important financing vehicle for oil and natural gas transport and processing infrastructure in the United States. An MLP is a type of publicly-traded partnership whereby limited partners purchase “units” on an exchange. In a traditional structure, the MLP is 98% owned by limited partners; the remaining 2% is owned by the general partner. The MLP pays distributions to limited partners, which operate similarly to dividends paid by traditional C-Corporations. In many MLPs, the general partner also owns incentive distribution rights (IDRs) to its general partner, which entitles it to a growing percentage of the distribution as quarterly distributions to the limited partners increase. Beginning in late 2009, capital investment in the midstream space grew substantially to support the increased production emerging from the shale boom. Because of the tax advantage that the MLP mode provided, companies formed MLPs to hold these assets. The number of energy MLPs grew from 16 in 1995 to a peak of 124 in 2013.However, between the summer of 2014 and early 2016, crude oil and natural gas lost nearly 75% and 60% of their values, respectively. As MLPs have faced challenges in recovering from the market downturn, many have shifted away from the traditional model that was created 1981. Two key trends have emerged: (1) the “roll-up” of MLPs into their corporate parent companies and (2) the elimination of incentive distribution rights (IDR) payments to the general partner, which had traditionally been used as a form of informal corporate governance. This paper seeks to answer the following questions: 1. Why has the MLP model has historically been a successful vehicle for aggregating capital and encouraging infrastructure investment? 2. What factors in the MLP model contributed to a performance decline in 2014 and 2015? 3. How will energy companies continue to use the MLP model as a vehicle for financing projects moving forward? This paper seeks to answer these questions through three case-study study analyses of recent “roll-up” and simplification transactions, which serve as representations of broader market trends. The case studies discussed in this paper are the roll-up of Targa Resources Partners (NGLS) into its parent company Targa Resources Corporation (TGRP), the roll-up of ONEOK Partners (OKS) into its parent company ONEOK, Inc. (OKE), and Plains All American’s (PAA) decision to purchase its general partners’ 2% ownership interest. Each MLP is a unique entity structures that involves complex financial engineering aimed at producing the most tax efficient and profitable firm while maintaining long term stable cash flows. Each case, although unique, presents various firms reactions to the recent market changes. Through our research, we identified primary problems faced by MLPs in the market downturn. First, because MLPs trade on yield, they face a heightened pressure to continue to grow distributions. This growth became unsustainable in the lower-cash flow environment of 2015, leading to lower coverage ratios. Second, a substantial portion of an MLPs distributable cash is paid to the general partner, rather than the limited partners, through IDRs. While required by most partnership agreements, these IDRs erode the cost-of-capital advantage of an MLP. Third, while the midstream sector is typically characterized by fee-based revenues, MLPs still faced direct commodity exposure during this period, causing variability in cash flows. While there has been some recovery in the commodity market, MLPs have been slower to recover, and, as such, many have chosen to pursue roll-up or simplification transactions. However, we believe the MLP model will still be utilized moving forward. Investment in upstream crude oil and natural gas production is predicted to increase. Further, a new trend of companies forming MLPs to support their own, rather than third-party, upstream operations is emerging. Our research suggests that operating an MLP in this environment requires a heightened awareness of (1) the true cost of IDRs, should an MLP choose to continue to include these in their partnership agreement; (2) unsustainable distribution growth, and (3) revenue streams that are not backed by long-term, fee-based contracts, thereby exposing the MLP to commodity price fluctuations.Item Open Access Mobile Sensors: Assessment of Fugitive Methane Emissions from Near and Far-Field Sources(2015) FosterWittig, TierneyThe primary focus of this dissertation is on the assessment of fugitive methane emissions from near and far-field sources. Methane is the second most prevalent greenhouse gas (GHG) emitted in the United States from anthropogenic activities. Due to measurement and model limitations, there is not an accurate assessment of how much methane in the atmosphere is due to anthropogenic sources. This dissertation focuses on measuring the methane emissions from two of the three largest anthropogenic sources -- landfills and natural gas systems. All measurements are made with a single fixed or single mobile sensor. Methods are developed to assess the source strength for both near (i.e. natural gas) and far-field (i.e. landfill) sources using either the fixed or mobile sensor.
For far-field measurements, a standardized version of a mobile tracer correlation measurement method was developed and used for assessment of methane emissions from 15 landfills in 56 field deployments from 2009 to 2013. A total of 1876 mobile tracer correlation measurement transects were attempted over 131 field sampling days.
Transects were analyzed using signal to noise ratio, plume correlation, and emission rate difference method quality indicators. The application of the method quality indicators yield 456 transects (33\%) that pass data acceptance criteria.
For near-field sources, techniques are developed for 1) fixed sensors sampling through time downwind of a source and 2) mobile sensors passing across plumes downwind of a source. For the fixed sensor, the lateral plume geometry is reconstructed from the fluctuating wind direction using a derived relationship between the wind direction and crosswind plume position. The crosswind plume spread is estimated with two different methods (modeled and observed), and subsequently used a Gaussian plume inversion to estimate the source strengths. For the fixed sensor, the sensor takes measurements for about 20 minutes and we are able to reconstruct the ensemble average of the plume.
For the mobile sensor, the vehicle drives through the plume in the crosswind direction.
The measurements show the lateral plume geometry of an instantaneous plume. The instantaneous plume has a narrowed Gaussian structure.
Two techniques are tested using data from controlled methane release experiments; these two techniques are 1) linear-squares and 2) a probabilistic approach. For the probabilistic approach, Bayesian inference tools are applied and special attention is paid to the relevant likelihood functions for both short time averaged concentrations from a single fixed sensor and spatial transects of instantaneous concentration measurements from a mobile sensor. The two techniques are also tested on measurements downwind of multiple natural gas production facilities in Wyoming for the fixed sensor and in Colorado for the moving sensor. The results for both the fixed and mobile techniques show promise for use with gas sensors on industry work trucks, opportunistically providing surveillance over a region of well pads.
Item Open Access POLICY IMPLICATIONS OF NATIONALIZATION OF OIL AND NATURAL GAS INDUSTRY IN LATIN AMERICA(2007-05) Cabezas, Brian F.Nationalization is a particular type of organizational structure where the state or nation controls the industry as opposed to private companies or multinational organizations. If one imagines a continuum of organizational structure, nationalization and privatization would be at opposite ends. Nationalization could include joint ventures where the state controls the industry but allows for private companies to participate in the resource extraction and retain some of the profit. Within the past few years, Venezuela and Bolivia have announced plans to renationalize their oil and natural gas industry. The first part of this project seeks to perform a qualitative analysis to discern the common characteristics of a nationalized country focusing specifically on four countries – Bolivia, Venezuela, Mexico and Nigeria. There are various components influencing the efficiency of a nationalized industry including civil society, regionalism, and reliance on oil. The main findings were that a nationalized country with a high reliance on oil or natural gas and weak financial institutions will have an authoritarian form of government, and that there will likely be more incidences of Latin American countries nationalizing in the near future if oil prices remain high. The project also performs a quantitative analysis on indirect measures of efficiency using subsidies and also analyzes the effect of nationalization on social development using the Gini coefficient (a measure of income equality) and public spending on education. Nationalization is found to have a positive effect on income equality and a negative effect on public spending on education. The project culminates with policy recommendations specifically focused on the four selected countries with implications for broader applications. The main objectives of the recommendations are to strengthen financial institutions, diversify the economy, and increase transparency and accountability of the industry.Item Open Access Reducing US Greenhouse Gas Emissions through a Replacement of Coal with Natural Gas in Power Generation(2010-04-29T21:52:36Z) Crowe, Parker DCurrently, coal provides about 50% of U.S. electricity supply and releases 80% of electricity sector carbon dioxide (Annual Energy Outlook Early Release Overview, 2009). A conceptual instantaneous switch to modern natural gas plants of the same capacity would reduce these carbon dioxide emissions by 74% or 1.5 annual gigatons at the cost of $300 billion in construction capital and an increase in electricity rates of approximately 15%. This analysis is accomplished primarily through a comparison of derived marginal cost functions for gas and coal generation under the assumption that fuel choice for baseload power is driven primarily by the lowest available cost of operation. The use of comparative supply curves demonstrates the extent of the cost disadvantage of gas to coal and allows analysis of possible future scenarios through manipulation of model inputs of fuel and emissions costs. In order for gas power to become less expensive than that from coal, either the price of gas must fall or the price of coal must rise. Two likely future developments might cause both of these changes to occur. Newly expected natural gas supply from unconventional sources and international trade of liquefied methane will put downward pressure on gas prices. Perhaps at the same time, a U.S. federal climate law could introduce a price on carbon emissions which would disproportionately raise the price of coal power. This analysis shows that either situation will promote gas power if of great enough magnitude. The likelihood of a transition away from coal remains questionable but coal is no longer the obvious fuel choice in new baseload power plant construction.Item Open Access The Impact of Electricity Storage on Energy Sector Emissions(2011-04-29) Keaveny, BrianThe composition of the U.S. electrical power system reflects competing objectives, as investments are driven by ratepayers who demand access to electricity that is both low cost and reliable. Maintaining generation ready for fluctuations in demand currently requires the inefficient use of generation assets, driving up total energy system costs. During the night, low demand for electricity can force the underutilization of wind farms and baseload coal-fired plants. During the day, load-following natural gas-fired plants are often operated at partial capacity so they can be ramped up to track changing demand. One means to address these two issues is electricity storage. Electricity storage technologies are capable of shifting surplus low cost nighttime electricity to times of higher daytime demand. Whether time-shifting electricity storage technologies may enable lower energy system costs depends upon the parameters of these technologies and future conditions. In this study, a least-cost optimization energy model (MARKAL) managed by U.S. EPA is used to explore the potential future role of electricity storage under varying conditions. Scenarios model a stricter national renewable portfolio standard (RPS), varying natural gas prices, and a national limit on CO2 emissions from the energy system. Scenario results are analyzed to discern the impact of electricity storage on generation output and on the associated energy sector emissions of CO2, SO2, NOx, and PM10. Four trends emerge when examining the impacts of time-shifting electricity storage on the national energy system. First, electricity storage enables an increasing utilization of baseload generation and a corresponding decreasing reliance on daytime load-following generation. Second, and to a lesser degree, nighttime natural gas-fired generation increases, making use of existing capacity. Third, the overall decreasing natural gas use by load-following generation leads to the increasing use of natural gas in the industrial sector. Fourth, the use of time-shifting electricity storage does not result in net increases of electricity output from renewable power sources. The impacts of these four trends on generation investments and emissions vary by the future conditions modeled. In many instances the use of electricity storage results in a less expensive energy system with higher emissions of CO2, SO2, NOx, and PM10.Item Open Access The Water-Energy Nexus for Hydraulic Fracturing(2019) Kondash, Andrew JohnThe water energy nexus represents the intersection of water use, energy production, electricity generation, and waste generation and disposal. The rapid rise of unconventional natural gas and oil production through the combined processes of horizontal drilling and hydraulic fracturing have shifted the energy dynamic in the United States. Concurrently, the rising utilization of unconventional gas and oil production has intensified the water use for hydraulic fracturing and generation of flowback and produced water associated with shale gas and tight oil production. Among the major environmental risks associated with the rise of unconventional oil and gas exploration water availability, water contamination from leaking or disposal of wastewater, and adequate disposal of the wastewater are the key issues associated with the water-energy nexus. This dissertation aims to quantify the water use for hydraulic fracturing across the U.S., evaluate the water use for electricity production from natural gas in comparison to coal combustion, estimate the flowback and produced water production, and assess possible recycling of oilfield water through irrigation in California.
This dissertation describes the water footprint of hydraulic fracturing by examining total water use, water use per well, water use per length of horizontal well, and the changes in water use through time. The data show that hydraulic fracturing water use per well has been increasing between early stages (2008-2012) to later stages (2012-2016) of operation. In addition to water use, this dissertation estimated waste water generated from unconventional oil and gas wells and find a concurrent increase in flowback and produced water (FP water) per well through time. Using salinity as a marker to distinguish FP water from water injected for hydraulic fracturing, this dissertation observes the sequestration of the injected freshwater, while the return flow composed primarily of more saline formation brines entrapped within the shale formations.
In addition, this this dissertation explored two downstream impacts of the increasing water use and FP water generation. First, as abundant natural gas resources from the expansion of hydraulic fracturing have shifted the electricity sector from primarily coal- to primarily natural gas-fired, this study examined the impact increasing water use associated with hydraulic fracturing has had on power plant lifecycle water consumption and withdrawal. The study found that despite increasing water use for hydraulic fracturing, natural gas-fired generation on average used less water for cooling relative to coal-fired generation. Finally, this this dissertation examined the risks from recycling of oilfield produced water (OPW) as an agricultural makeup water source. The data from field studies in California show that by using low salinity OPW, farmers are able to successfully recycle OPW without risking metals accumulation in soil and consequently in crop and human health.