Matching Items (7)
Description
There is growing concern over the future availability of water for electricity generation. Because of a rapidly growing population coupled with an arid climate, the Western United States faces a particularly acute water/energy challenge, as installation of new electricity capacity is expected to be required in the areas with the most limited water availability. Electricity trading is anticipated to be an important strategy for avoiding further local water stress, especially during drought and in the areas with the most rapidly growing populations. Transfers of electricity imply transfers of "virtual water" - water required for the production of a product. Yet, as a result of sizable demand growth, there may not be excess capacity in the system to support trade as an adaptive response to long lasting drought. As the grid inevitably expands capacity due to higher demand, or adapts to anticipated climate change, capacity additions should be selected and sited to increase system resilience to drought. This paper explores the tradeoff between virtual water and local water/energy infrastructure development for the purpose of enhancing the Western US power grid's resilience to drought. A simple linear model is developed that estimates the economically optimal configuration of the Western US power grid given water constraints. The model indicates that natural gas combined cycle power plants combined with increased interstate trade in power and virtual water provide the greatest opportunity for cost effective and water efficient grid expansion. Such expansion, as well as drought conditions, may shift and increase virtual water trade patterns, as states with ample water resources and a competitive advantage in developing power sources become net exporters, and states with limited water or higher costs become importers.
ContributorsHerron, Seth (Author) / Ruddell, Benjamin L (Thesis advisor) / Ariaratnam, Samuel (Thesis advisor) / Allenby, Braden (Committee member) / Williams, Eric (Committee member) / Arizona State University (Publisher)
Created2013
Description
Urban water systems face sustainability challenges ranging from water quality, leaks, over-use, energy consumption, and long-term supply concerns. Resiliency challenges include the capacity to respond to drought, managing pipe deterioration, responding to natural disasters, and preventing terrorism. One strategy to enhance sustainability and resiliency is the development and adoption of smart water grids. A smart water grid incorporates networked monitoring and control devices into its structure, which provides diverse, real-time information about the system, as well as enhanced control. Data provide input for modeling and analysis, which informs control decisions, allowing for improvement in sustainability and resiliency. While smart water grids hold much potential, there are also potential tradeoffs and adoption challenges. More publicly available cost-benefit analyses are needed, as well as system-level research and application, rather than the current focus on individual technologies. This thesis seeks to fill one of these gaps by analyzing the cost and environmental benefits of smart irrigation controllers. Smart irrigation controllers can save water by adapting watering schedules to climate and soil conditions. The potential benefit of smart irrigation controllers is particularly high in southwestern U.S. states, where the arid climate makes water scarcer and increases watering needs of landscapes. To inform the technology development process, a design for environment (DfE) method was developed, which overlays economic and environmental performance parameters under different operating conditions. This method is applied to characterize design goals for controller price and water savings that smart irrigation controllers must meet to yield life cycle carbon dioxide reductions and economic savings in southwestern U.S. states, accounting for regional variability in electricity and water prices and carbon overhead. Results from applying the model to smart irrigation controllers in the Southwest suggest that some areas are significantly easier to design for.
ContributorsMutchek, Michele (Author) / Allenby, Braden (Thesis advisor) / Williams, Eric (Committee member) / Westerhoff, Paul (Committee member) / Arizona State University (Publisher)
Created2012
Description
In the U.S., high-speed passenger rail has recently become an active political topic, with multiple corridors currently being considered through federal and state level initiatives. One frequently cited benefit of high-speed rail proposals is that they offer a transition to a more sustainable transportation system with reduced greenhouse gas emissions and fossil energy consumption. This study investigates the feasibility of high-speed rail development as a long-term greenhouse gas emission mitigation strategy while considering major uncertainties in the technological and operational characteristics of intercity travel. First, I develop a general model for evaluating the emissions impact of intercity travel modes. This model incorporates aspects of life-cycle assessment and technological forecasting. The model is then used to compare future scenarios of energy and greenhouse gas emissions associated with the development of high-speed rail and other intercity travel technologies. Three specific rail corridors are evaluated and policy guidelines are developed regarding the emissions impacts of these investments. The results suggest prioritizing high-speed rail investments on short, dense corridors with fewer stops. Likewise, less emphasis should be placed on larger investments that require long construction times due to risks associated with payback of embedded emissions as competing technology improves.
ContributorsBurgess, Edward (Author) / Williams, Eric (Thesis advisor) / Fink, Jonathan (Thesis advisor) / Yaro, Robert (Committee member) / Arizona State University (Publisher)
Created2011
Description
Economic development over the last century has driven a tripling of the world's population, a twenty-fold increase in fossil fuel consumption, and a tripling of traditional biomass consumption. The associated broad income and wealth inequities are retaining over 2 billion people in poverty. Adding to this, fossil fuel combustion is impacting the environment across spatial and temporal scales and the cost of energy is outpacing all other variable costs for most industries. With 60% of world energy delivered in 2008 consumed by the commercial and industrial sector, the fragmented and disparate energy-related decision making within organizations are largely responsible for the inefficient and impacting use of energy resources. The global transition towards sustainable development will require the collective efforts of national, regional, and local governments, institutions, the private sector, and a well-informed public. The leadership role in this transition could be provided by private and public sector organizations, by way of sustainability-oriented organizations, cultures, and infrastructure. The diversity in literature exemplifies the developing nature of sustainability science, with most sustainability assessment approaches and frameworks lacking transformational characteristics, tending to focus on analytical methods. In general, some shortfalls in sustainability assessment processes include lack of: * thorough stakeholder participation in systems and stakeholder mapping, * participatory envisioning of future sustainable states, * normative aggregation of results to provide an overall measure of sustainability, and * influence within strategic decision-making processes. Specific to energy sustainability assessments, while some authors aggregate results to provide overall sustainability scores, assessments have focused solely on energy supply scenarios, while including the deficits discussed above. This paper presents a framework for supporting organizational transition processes towards sustainable energy systems, using systems and stakeholder mapping, participatory envisioning, and sustainability assessment to prepare the development of transition strategies towards realizing long-term energy sustainability. The energy system at Arizona State University's Tempe campus (ASU) in 2008 was used as a baseline to evaluate the sustainability of the current system. From interviews and participatory workshops, energy system stakeholders provided information to map the current system and measure its performance. Utilizing operationalized principles of energy sustainability, stakeholders envisioned a future sustainable state of the energy system, and then developed strategies to begin transition of the current system to its potential future sustainable state. Key findings include stakeholders recognizing that the current energy system is unsustainable as measured against principles of energy sustainability and an envisioned future sustainable state of the energy system. Also, insufficient governmental stakeholder engagement upstream within the current system could lead to added risk as regulations affect energy supply. Energy demand behavior and consumption patterns are insufficiently understood by current stakeholders, limiting participation and accountability from consumers. In conclusion, although this research study focused on the Tempe campus, ASU could apply this process to other campuses thereby improving overall ASU energy system sustainability. Expanding stakeholder engagement upstream within the energy system and better understanding energy consumption behavior can also improve long-term energy sustainability. Finally, benchmarking ASU's performance against its peer universities could expand the current climate commitment of participants to broader sustainability goals.
ContributorsBuch, Rajesh (Author) / Wiek, Arnim (Thesis advisor) / Basile, George (Thesis advisor) / Williams, Eric (Committee member) / Arizona State University (Publisher)
Created2011
Description
Carbon capture and sequestration (CCS) is one of the important mitigation options for climate change. Numerous technologies to capture carbon dioxide (CO2) are in development but currently, capture using amines is the predominant technology. When the flue gas reacts with amines (Monoethanaloamine) the CO2 is absorbed into the solution and forms an intermediate product which then releases CO2 at higher temperature. The high temperature necessary to strip CO2 is provided by steam extracted from the powerplant thus reducing the net output of the powerplant by 25% to 35%. The reduction in electricity output for the same input of coal increases the emissions factor of Nitrogen Oxides, Mercury, Particulate matter, Ammonia, Volatile organic compounds for the same unit of electricity produced. The thesis questions if this tradeoff between CO2 and other emissions is beneficial or not. Three different methodologies, Life Cycle Assessment, Valuation models and cost benefit analysis are used to identify if there is a net benefit to the society on implementation of CCS to a Pulverized coal powerplant. These methodologies include the benefits due to reduction of CO2 and the disbenefits due to the increase of other emissions. The life cycle assessment using ecoindicator'99 methodology shows the CCS is not beneficial under Hierarchical and Egalitarian perspective. The valuation model shows that the inclusion of the other emissions reduces the benefit associated with CCS. For a lower CO2 price the valuation model shows that CCS is detrimental to the environment. The cost benefit analysis shows that a CO2 price of at least $80/tCO2 is required for the cost benefit ratio to be 1. The methodology integrates Montecarlo simulation to characterize the uncertainties associated with the valuation models.
ContributorsSekar, Ashok (Author) / Williams, Eric (Thesis advisor) / Chester, Mikhail (Thesis advisor) / Allenby, Braden (Committee member) / Arizona State University (Publisher)
Created2012
Description
Electronic waste (E-waste) is a concern, because of the increasing volume of materials being disposed of. There are economical, social and environmental implications derived from these materials. For example, the international trade of used computers creates jobs, but the recovery from valuable materials is technically challenging and currently there are environmental and health problems derived from inappropriate recycling practices. Forecasting the flows of used computers and e-waste materials supports the prevention of environmental impacts. However, the nature of these material flows is complex. There are technological geographical and cultural factors that affect how users purchase, store or dispose of their equipment. The result of these dynamics is a change in the composition and volume of these flows. Collectors are affected by these factors and the presence of markets, labor and transportation costs. In northern Mexico, there is an international flow of new and used computers between Mexico and the United States and an internal flow of materials and products among Mexican cities. In order to understand the behavior of these flows a field study was carried out in 8 different Mexican cities. Stake holders were interviewed and through a structured analysis the system and the relevant stakeholders were expressed as Data Flow Diagrams in order; to understand the critical parts from the system. The results show that Mexican cities have important qualitative differences. For example, location and size define the availability of resources to manage e-waste. Decisions to dispose a computer depend on international factors such as the price of new computers, but also on regional factors such as the cost to repair them. Decisions to store a computer depend on external factors such as markets, but also internal factors such as how users perceive the value of old equipment. E-waste collection depends on the value of e-waste, but also on costs to collect and extract value from them. The main implication is that a general policy base on how E-waste is managed at a big city might not be the most efficient for a small one. More over combining strengths from different cities might overcome respective weaknesses and create new opportunities; this integration can be stimulated by designing policies that consider diversity
ContributorsEstrada Ayub, Jesus Angel (Author) / Allenby, Braden R. (Thesis advisor) / Ramzy, Kahhat A (Thesis advisor) / Kahhat, Ramzy A (Committee member) / Williams, Eric (Committee member) / Arizona State University (Publisher)
Created2012
Description
Urban water systems face sustainability and resiliency challenges including water leaks, over-use, quality issues, and response to drought and natural disasters. Information and communications technology (ICT) could help address these challenges through the development of smart water grids that network and automate monitoring and control devices. While progress is being made on technology elements, as a system, the smart water grid has received scant attention. This article aims to raise awareness of the systems-level idea of smart water grids by reviewing the technology elements and their integration into smart water systems, discussing potential sustainability and resiliency benefits, and challenges relating to the adoption of smart water grids. Water losses and inefficient use stand out as promising areas for applications of smart water grids. Potential barriers to the adoption of smart water grids include lack of funding for research and development, economic disincentives as well as institutional and political structures that favor the current system. It is our hope that future work can clarify the benefits of smart water grids and address challenges to their further development.
ContributorsMutchek, Michele (Author) / Williams, Eric (Author) / Ira A. Fulton Schools of Engineering (Contributor)
Created2014-03-21