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Evacuated tube solar thermal collector arrays have a wide range of applications. While most of these applications are limited in performance due to relatively low maximum operating temperatures, these collectors can still be useful in low grade thermal systems. An array of fifteen Apricus AP-30 evacuated tube collectors was designed,

Evacuated tube solar thermal collector arrays have a wide range of applications. While most of these applications are limited in performance due to relatively low maximum operating temperatures, these collectors can still be useful in low grade thermal systems. An array of fifteen Apricus AP-30 evacuated tube collectors was designed, assembled, and tested on the Arizona State University campus in Tempe, AZ. An existing system model was reprogrammed and updated for increased flexibility and ease of use. The model predicts the outlet temperature of the collector array based on the specified environmental conditions. The model was verified through a comparative analysis to the data collected during a three-month test period. The accuracy of this model was then compared against data calculated from the Solar Rating and Certification Corporation (SRCC) efficiency curve to determine the relative performance. It was found that both the original and updated models were able to generate reasonable predictions of the performance of the collector array with overall average percentage errors of 1.0% and 1.8%, respectively.
ContributorsStonebraker, Matthew (Author) / Phelan, Patrick (Thesis advisor) / Reddy, Agami (Committee member) / Bryan, Harvey (Committee member) / Arizona State University (Publisher)
Created2011
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Description
Solar panels need to be both cost effective and environmentally friendly to compete with traditional energy forms. Photovoltaic recycling has the potential to mitigate the harm of waste, which is often landfilled, while putting material back into the manufacturing process. Out of many, three methods show much promise: Full Recovery

Solar panels need to be both cost effective and environmentally friendly to compete with traditional energy forms. Photovoltaic recycling has the potential to mitigate the harm of waste, which is often landfilled, while putting material back into the manufacturing process. Out of many, three methods show much promise: Full Recovery End-of-Life Photovoltaic (FRELP), mechanical, and sintering-based recycling. FRELP recycling has quickly gained prominence in Europe and promises to fully recover the components in a solar cell. The mechanical method has produced high yields of valuable materials using basic and inexpensive processes. The sintering method has the potential to tap into a large market for feldspar. Using a levelized cost of electricity (LCOE) analysis, the three methods could be compared on an economic basis. This showed that the mechanical method is least expensive, and the sintering method is the most expensive. Using this model, all recycling methods are less cost effective than the control analysis without recycling. Sensitivity analyses were then done on the effect of the discount rate, capacity factor, and lifespan on the LCOE. These results showed that the change in capacity factor had the most significant effect on the levelized cost of electricity. A final sensitivity analysis was done based on the decreased installation and balance of systems costs in 2025. With a 55% decrease in these costs, the LCOE decreased by close to $0.03/kWh for each method. Based on these results, the cost of each recycling method would be a more considerable proportion of the overall LCOE of the solar farm.
ContributorsMeister, William Frederick (Author) / Goodnick, Stephen (Thesis director) / Phelan, Patrick (Committee member) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
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Description
The energy crisis in the past decades has greatly boosted the search for alternatives to traditional fossil foils, and solar energy stands out as an important candidate due to its cleanness and abundance. However, the relatively low conversion efficiency and energy density strongly hinder the utilization of solar energy in

The energy crisis in the past decades has greatly boosted the search for alternatives to traditional fossil foils, and solar energy stands out as an important candidate due to its cleanness and abundance. However, the relatively low conversion efficiency and energy density strongly hinder the utilization of solar energy in wider applications. This thesis focuses on employing metamaterials and metafilms to enhance the conversion efficiency of solar thermal, solar thermophotovoltaic (STPV) and photovoltaic systems.

A selective metamaterial solar absorber is designed in this thesis to maximize the absorbed solar energy and minimize heat dissipation through thermal radiation. The theoretically designed metamaterial solar absorber exhibits absorptance higher than 95% in the solar spectrum but shows emittance less than 4% in the IR regime. This metamaterial solar absorber is further experimentally fabricated and optically characterized. Moreover, a metafilm selective absorber with stability up to 600oC is introduced, which exhibits solar absorptance higher than 90% and IR emittance less than 10%.

Solar thermophotovoltaic energy conversion enhanced by metamaterial absorbers and emitters is theoretically investigated in this thesis. The STPV system employing selective metamaterial absorber and emitter is investigated in this work, showing its conversion efficiency between 8% and 10% with concentration factor varying between 20 and 200. This conversion efficiency is remarkably enhanced compared with the conversion efficiency for STPV system employing black surfaces (<2.5%).

Moreover, plasmonic light trapping in ultra-thin solar cells employing concave grating nanostructures is discussed in this thesis. The plasmonic light trapping inside an ultrathin GaAs layer in the film-coupled metamaterial structure is numerically demonstrated. By exciting plasmonic resonances inside this structure, the short-circuit current density for the film-coupled metamaterial solar cell is three times the short-circuit current for a free-standing GaAs layer.

The dissertation is concluded by discussing about the future work on selective solar thermal absorbers, STPV/TPV systems and light trapping structures. Possibilities to design and fabricate solar thermal absorber with better thermal stability will be discussed, the experimental work of TPV system will be conducted, and the light trapping in organic and perovskite solar cells will be looked into.
ContributorsWang, Hao (Author) / Wang, Liping (Thesis advisor) / Phelan, Patrick (Committee member) / Wang, Robert (Committee member) / Dai, Lenore (Committee member) / Rykaczewski, Konrad (Committee member) / Arizona State University (Publisher)
Created2016
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Description
With an abundance of sunshine, the state of Arizona has the potential for producing large amounts of solar energy. However, in recent years Arizona has also become the focal point in a political battle to determine the value and future of residential solar energy fees, which has critical implications for

With an abundance of sunshine, the state of Arizona has the potential for producing large amounts of solar energy. However, in recent years Arizona has also become the focal point in a political battle to determine the value and future of residential solar energy fees, which has critical implications for distributed generation. As the debate grows, it is clear that solar policies developed in Arizona will influence other state regulators regarding their solar rate structures and Net Energy Metering; however, there is a hindrance in the progress of this discussion due to the varying frameworks of the stakeholders involved. For this project, I set out to understand and analyze why the different stakeholders have such conflicting viewpoints. Some groups interpret energy as a financial and technological object while others view it is an inherently social and political issue. I conducted research in three manners: 1) I attended public meetings, 2) hosted interviews, and 3) analyzed reports and studies on the value of solar. By using the SRP 2015 Rate Case as my central study, I will discuss how these opposing viewpoints do or do not incorporate various forms of justice such as distributive, participatory, and recognition justice. In regards to the SRP Rate Case, I will look at both the utility- consumer relationship and the public meeting processes in which they interact, in addition to the pricing plans. This work reveals that antiquated utility structures and a lack of participation and recognition justice are hindering the creation of policy changes that satisfy both the needs of the utilities and the community at large.
ContributorsGidney, Jacob Robert (Author) / Richter, Jennifer (Thesis director) / Jurik, Nancy (Committee member) / School of Mathematical and Statistical Sciences (Contributor) / Department of Economics (Contributor) / Barrett, The Honors College (Contributor)
Created2015-12
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Description
Concentrating solar thermal power systems gained a wide interest for a long time to serve as a renewable and sustainable alternate source of energy. While the optimization and modification are ongoing, focused generally on solar power systems to provide solar-electrical energy or solar-thermal energy, the production process of Ordinary Portland

Concentrating solar thermal power systems gained a wide interest for a long time to serve as a renewable and sustainable alternate source of energy. While the optimization and modification are ongoing, focused generally on solar power systems to provide solar-electrical energy or solar-thermal energy, the production process of Ordinary Portland Cement (OPC) has not changed over the past century. A linear refractive Fresnel lens application in cement production process is investigated in this research to provide the thermal power required to raise the temperature of lime up to 623 K (350C) with zero carbon emissions for stage two in a new proposed two-stage production process. The location is considered to be Phoenix, Arizona, with a linear refractive Fresnel lens facing south, tilted 33.45 equaling the location latitude, and concentrating solar beam radiation on an evacuated tube collector with tracking system continuously rotating about the north-south axis. The mathematical analysis showed promising results based on averaged monthly values representing an average hourly useful thermal power and receiver temperature during day-light hours for each month throughout the year. The maximum average hourly useful thermal power throughout the year was obtained for June as 33 kWth m-2 with a maximum receiver temperature achieved of 786 K (513C), and the minimum useful thermal power obtained during the month of December with 27 kWth m-2 and a minimum receiver temperature of 701 K (428C).
ContributorsAlkhuwaiteem, Mohammad (Author) / Phelan, Patrick (Thesis advisor) / Shuaib, Abdelrahman (Committee member) / Neithalath, Narayanan (Committee member) / Arizona State University (Publisher)
Created2021
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Description
As India expanded its grid infrastructure, decentralized renewable energy technologies, such as off-grid solar, also emerged in parallel as an electrification solution. This dissertation critically examines the role of off-grid solar in facilitating rural electrification efforts in India. Specifically, it applies the frameworks of the multi-level perspective, capabilities approach, and

As India expanded its grid infrastructure, decentralized renewable energy technologies, such as off-grid solar, also emerged in parallel as an electrification solution. This dissertation critically examines the role of off-grid solar in facilitating rural electrification efforts in India. Specifically, it applies the frameworks of the multi-level perspective, capabilities approach, and energy justice to achieve three objectives: (1) trace the evolution of off-grid solar in India; (2) understand the role of solar micro-grids in improving household capabilities and well-being; (1) examine whether and how community-scale solar micro-grids can operate as just means of electrification. This research relies on qualitative case-study methods. The historical research in Paper 1 is based on published policy documents and interviews with energy experts in India. It finds that landscape-regime-niche actor relations and politics were crucial in shaping off-grid solar transition outcomes. There is also a narrative component, as the key narratives of energy security, environmental degradation, climate change and energy for development converged to create spaces for state and non-state interactions that could nurture the development of off-grid solar. The community-level research in Papers 2 and 3 analyze a local energy initiative of community operated solar micro-grid using semi-structured interviews and participant observations from three villages in Maharashtra. Solar micro-grids play an important part in expanding people’s choices and opportunities. The benefits are not uniform across all people, however. Increases in energy-related capabilities vary by economic class and gender, and to some extent this means certain biases can get reinforced. In addition, the inability of solar micro-grids to keep up with the changing electrification landscape and daily practices means that the challenges of affordability, reliability and community engagement emerged as important concerns over-time. Empirically, this dissertation finds that off-grid energy initiatives must be carefully designed to be in alignment with local values and realities. Theoretically, it adds to debates on justice in energy transitions by showcasing the regime-led innovations, and temporality elements of energy justice local energy initiatives.
ContributorsRajagopalan, Sushil (Author) / Breetz, Hanna (Thesis advisor) / Klinsky, Sonja (Thesis advisor) / Singh, Kartikeya (Committee member) / Arizona State University (Publisher)
Created2021