Browsing by Subject "renewable energy"

Now showing 1 - 8 of 8

Cow power: The energy and emissions benefits of converting manure to biogas
(IOP Publishing, 2008-07-24) Cuellar, Amanda D.; Webber, Michael E.; Cuellar, Amanda D.; Webber, Michael E.
This report consists of a top-level aggregate analysis of the total potential for converting livestock manure into a domestic renewable fuel source (biogas) that could be used to help states meet renewable portfolio standard requirements and reduce greenhouse gas (GHG) emissions. In the US, livestock agriculture produces over one billion tons of manure annually on a renewable basis. Most of this manure is disposed of in lagoons or stored outdoors to decompose. Such disposal methods emit methane and nitrous oxide, two important GHGs with 21 and 310 times the global warming potential of carbon dioxide, respectively. In total, GHG emissions from the agricultural sector in the US amounted to 536 million metric tons (MMT) of carbon dioxide equivalent, or 7% of the total US emissions in 2005. Of this agricultural contribution, 51 to 118 MMT of carbon dioxide equivalent resulted from livestock manure emissions alone, with trends showing this contribution increasing from 1990 to 2005. Thus, limiting GHG emissions from manure represents a valuable starting point for mitigating agricultural contributions to global climate change. Anaerobic digestion, a process that converts manure to methane-rich biogas, can lower GHG emissions from manure significantly. Using biogas as a substitute for other fossil fuels, such as coal for electricity generation, replaces two GHG sources—manure and coal combustion—with a less carbon-intensive source, namely biogas combustion. The biogas energy potential was calculated using values for the amount of biogas energy that can be produced per animal unit (defined as 1000 pounds of animal) per day and the number of animal units in the US. The 95 million animal units in the country could produce nearly 1 quad of renewable energy per year, amounting to approximately 1% of the US total energy consumption. Converting the biogas into electricity using standard microturbines could produce 88 ± 20 billion kWh, or 2.4 ± 0.6% of annual electricity consumption in the US. Replacing coal and manure GHG emissions with the emissions from biogas would produce a net potential GHG emissions reduction of 99 ± 59 million metric tons or 3.9 ± 2.3% of the annual GHG emissions from electricity generation in the US.
New York Throws Struggling Nuclear Generators a Lifeline, but Their Long-Term Survival Remains Uncertain
(2016-08-05) Webb, Romany
Opportunity on the Horizon: Photovoltaics in Texas
(IC² Institute, The University of Texas at Austin, 2007-06) Kellison, J. Bruce; Evans, Eliza; Houlihan, Katharine; Hoffman, Michael; Kuhn, Michael; Serface, Joel; Pham, Tuan
Report on the economic potential of the solar energy industry in Texas.
Public Policy for Sustainability: Analysis of Food Systems in Relation to Climate Change
(2023-05) Chuo, Anna; Swearingen, William
Many times, the principal solution to environmental challenges is to cut products and services out of our lives. But in reality, the story can’t be so simple, and that’s especially true with food. We will always need to consume it to survive. This simple truth challenges our current solution to the environmental challenges of climate change and pollution. Our current systems of resource distribution are unsustainable, and we must change this instead of refusing to deviate from the norm. There are many creative solutions we could implement to better ours and future generations’ lives. I want to explore how we can do so, namely in our production, distribution, and consumption of food. The food systems I will be analyzing will encapsulate the direct production of food as well as the processes that indirectly contribute. For the purposes of my thesis, I define sustainable as something that can continue long into the future and will propel itself to exist beyond one’s lifetime. Living sustainably also means we are able to replenish the resources we consume. There are concrete ways to improve our current systems to make them more sustainable, though some propositions require some fundamental changes to how we currently live. It does not mean the quality of our lives will decrease. However, if we continue with the status quo, the global standard of living will certainly decrease. Though it sounds melodramatic, studies and research continue to point to this fact. No longer is the question over whether climate change is happening; it now centers around what are we to do about it. My proposed solutions don’t center around individual action, they center around policy changes governments can implement to spur the change needed. Before I introduce my proposed policies, I want to analyze the causes of our current food system and how it came to be as it is today. Beyond the physical reasons, I also want to look into how sociology has exacerbated and fueled unsustainability. Particularly in America, overconsumption is a cornerstone of the culture, as well as the excessive production of waste. To make our society more sustainable means acknowledging this and actively working to change our society’s values. Along with sociological causes, I want to analyze the tangible effects our current food system has on our environment and ourselves. Global warming will be a glaring focal point of this section, as the symptoms of global warming will only exacerbate the other effects of unsustainable food systems. As the overall temperature of the planet continues to rise, the percent of arable land decreases, as well as an increase in instances of extreme weather. While coastal areas will receive more rainfall and hurricanes, landlocked areas (like the breadbasket of America) will have to deal with extreme droughts. Current narratives surrounding sustainability tell the bleak story of a desolate Earth stripped of its resources and a human population fighting for the scarce resources that remain. Recent advances in technology now tell us that this future does not have to be. As it becomes more clear how detrimental our current ways of life are for future generations, I understand how it is at times disheartening and difficult to think about. But through this thesis, I hope to prove otherwise.
Shaping the Energy Technology Transition: Moving to a Low-Carbon, Renewable-Energy Economy, PRP 167
(LBJ School of Public Affairs, 2009) Groat, Charles G.; Grimshaw, Thomas W.
Texas Energy: The Next Generation: The Role of Renewables in Generating Electricity
(Bureau of Business Research, The University of Texas at Austin, 2004-08) Dioun, Mina M.
In recent years, renewable energy has gained ground as a viable future source of energy in the electric industry. Such recognition has been due to the environmentally friendly aspects of renewables resources, federal government incentives and state government mandates, and declining costs due to technological progress. With natural gas price escalating and high volatility of gas prices, it is expected that future electricity generation from renewable resources, specifically wind, will become more competitive and economically feasible.
Toward A Renewable Energy Future The Urban Potential: Austin Texas, PRP 44
(LBJ School of Public Affairs, 1982) Blissett, Marlan
A unit commitment study of the application of energy storage toward the integration of renewable generation
(American Institute of Physics, 2012) Harris, Chioke B.; Meyers, Jeremy P.; Webber, Michael E.; Harris, Chioke B.; Meyers, Jeremy P.; Webber, Michael E.
To examine the potential benefits of energy storage in the electric grid, a generalized unit commitment model of thermal generating units and energy storage facilities is developed. Three different storage scenarios were tested—two without limits to total storage assignment and one with a constrained maximum storage portfolio. Given a generation fleet based on the City of Austin’s renewable energy deployment plans, results from the unlimited energy storage deployment scenarios studied show that if capital costs are ignored, large quantities of seasonal storage are preferred. This operational approach enables storage of plentiful wind generation during winter months that can then be dispatched during high cost peak periods in the summer. These two scenarios yielded $70 million and $94 million in yearly operational cost savings but would cost hundreds of billions to implement. Conversely, yearly cost reductions of $40 million can be achieved with one compressed air energy storage facility and a small set of electrochemical storage devices totaling 13GWh of capacity. Similarly sized storage fleets with capital costs, service lifetimes, and financing consistent with these operational cost savings can yield significant operational benefit by avoiding dispatch of expensive peaking generators and improving utilization of renewable generation throughout the year. Further study using a modified unit commitment model can help to clarify optimal storage portfolios, reveal appropriate market participation approaches, and determine the optimal siting of storage within the grid.