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Current policies subsidizing or accelerating deployment of photovoltaics (PV) are typically motivated by claims of environmental benefit, such as the reduction of CO2 emissions generated by the fossil-fuel fired power plants that PV is intended to displace. Existing practice is to assess these environmental benefits on a net life-cycle basis,

Current policies subsidizing or accelerating deployment of photovoltaics (PV) are typically motivated by claims of environmental benefit, such as the reduction of CO2 emissions generated by the fossil-fuel fired power plants that PV is intended to displace. Existing practice is to assess these environmental benefits on a net life-cycle basis, where CO2 benefits occurring during use of the PV panels is found to exceed emissions generated during the PV manufacturing phase including materials extraction and manufacture of the PV panels prior to installation. However, this approach neglects to recognize that the environmental costs of CO2 release during manufacture are incurred early, while environmental benefits accrue later. Thus, where specific policy targets suggest meeting CO2 reduction targets established by a certain date, rapid PV deployment may have counter-intuitive, albeit temporary, undesired consequences. Thus, on a cumulative radiative forcing (CRF) basis, the environmental improvements attributable to PV might be realized much later than is currently understood. This phenomenon is particularly acute when PV manufacture occurs in areas using CO2 intensive energy sources (e.g., coal), but deployment occurs in areas with less CO2 intensive electricity sources (e.g., hydro). This thesis builds a dynamic Cumulative Radiative Forcing (CRF) model to examine the inter-temporal warming impacts of PV deployments in three locations: California, Wyoming and Arizona. The model includes the following factors that impact CRF: PV deployment rate, choice of PV technology, pace of PV technology improvements, and CO2 intensity in the electricity mix at manufacturing and deployment locations. Wyoming and California show the highest and lowest CRF benefits as they have the most and least CO2 intensive grids, respectively. CRF payback times are longer than CO2 payback times in all cases. Thin film, CdTe PV technologies have the lowest manufacturing CO2 emissions and therefore the shortest CRF payback times. This model can inform policies intended to fulfill time-sensitive CO2 mitigation goals while minimizing short term radiative forcing.
ContributorsTriplican Ravikumar, Dwarakanath (Author) / Seager, Thomas P (Thesis advisor) / Fraser, Matthew P (Thesis advisor) / Chester, Mikhail V (Committee member) / Sinha, Parikhit (Committee member) / Arizona State University (Publisher)
Created2013
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Description
Research confirms that climate change is primarily due to the influx of greenhouse gases from the anthropogenic burning of fossil fuels for energy. Carbon dioxide (CO2) is the dominant greenhouse gas contributing to climate change. Although research also confirms that negative emission technologies (NETs) are necessary to stay within 1.5-2°C

Research confirms that climate change is primarily due to the influx of greenhouse gases from the anthropogenic burning of fossil fuels for energy. Carbon dioxide (CO2) is the dominant greenhouse gas contributing to climate change. Although research also confirms that negative emission technologies (NETs) are necessary to stay within 1.5-2°C of global warming, this dissertation proposes that the climate change problem has been ineffectively communicated to suggest that CO2 emissions reduction is the only solution to climate change. Chapter 1 explains that current United States (US) policies focus heavily on reducing CO2 emissions, but ignore the concentrations of previous CO2 emissions accumulating in the atmosphere. Through political, technological, and ethical lenses, this dissertation evaluates whether the management process of CO2 emissions and concentrations in the US today can effectively combat climate change.

Chapter 2 discusses the historical management of US air pollution, why CO2 is regulated as an air pollutant, and how the current political framing of climate change as an air pollution problem promotes the use of market-based solutions to reduce emissions but ignores CO2 concentrations. Chapter 3 argues for the need to reframe climate change solutions to include reducing CO2 concentrations along with emissions. It presents the scientific reasoning and technological needs for reducing CO2 concentrations, why direct air capture (DAC) is the most effective NET to do so, and existing regulatory systems that can inform future CO2 removal policy. Chapter 4 explores whether Responsible Innovation (RI), a framework that includes society in the innovation process of emerging technologies, is effective for the ethical research and deployment of DAC; reveals the need for increased DAC governance strategies, and suggests how RI can be expanded to allow continued research of controversial emerging technologies in case of a climate change emergency. Overall, this dissertation argues that climate change must be reframed as a two-part problem: preventing new CO2 emissions and reducing concentrations, which demands increased investment in DAC research, development, and deployment. However, without a national or global governance strategy for DAC, it will remain difficult to include CO2 concentration reduction as an essential piece to the climate change solution.
ContributorsMorton, Evvan (Author) / Lackner, Klaus S (Thesis advisor) / Allenby, Braden R. (Committee member) / Graffy, Elisabeth A. (Committee member) / Arizona State University (Publisher)
Created2020
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Description
As the global community raises concerns regarding the ever-increasing urgency of climate change, efforts to explore innovative strategies in the fight against this anthropogenic threat is growing. Along with other greenhouse gas mitigation technologies, Direct Air Capture (DAC) or the technology of removing carbon dioxide directly from the air has

As the global community raises concerns regarding the ever-increasing urgency of climate change, efforts to explore innovative strategies in the fight against this anthropogenic threat is growing. Along with other greenhouse gas mitigation technologies, Direct Air Capture (DAC) or the technology of removing carbon dioxide directly from the air has received considerable attention. As an emerging technology, the cost of DAC has been the prime focus not only in scientific society but also between entrepreneurs and policymakers. While skeptics are concerned about the high cost and impact of DAC implementation at scales comparable to the magnitude of climate change, industrial practitioners have demonstrated a pragmatic path to cost reduction. Based on the latest advancements in the field, this dissertation investigates the economic feasibility of DAC and its role in future energy systems. With a focus on the economics of carbon capture, this work compares DAC with other carbon capture technologies from a systemic perspective. Moreover, DAC’s major expenses are investigated to highlight critical improvements necessary for commercialization. In this dissertation, DAC is treated as a backstop mitigation technology that can address carbon dioxide emissions regardless of the source of emission. DAC determines the price of carbon dioxide removal when other mitigation technologies fall short in meeting their goals. The results indicate that DAC, even at its current price, is a reliable backup and is competitive with more mature technologies such as post-combustion capture. To reduce the cost, the most crucial component of a DAC design, i.e., the sorbent material, must be the centerpiece of innovation. In conclusion, DAC demonstrates the potential for not only negative emissions (carbon dioxide removal with the purpose of addressing past emissions), but also for addressing today’s emissions. The results emphasize that by choosing an effective scale-up strategy, DAC can become sufficiently cheap to play a crucial role in decarbonizing the energy system in the near future. Compared to other large-scale decarbonization strategies, DAC can achieve this goal with the least impact on our existing energy infrastructure.
ContributorsAzarabadi, Habib (Author) / Lackner, Klaus S (Thesis advisor) / Allenby, Braden R. (Committee member) / Dirks, Gary W (Committee member) / Reddy, Agami (Committee member) / Arizona State University (Publisher)
Created2020