Master of Science (M.S.), University of Dayton, 2017, Renewable and Clean Energy

Photovoltaic-thermal (PVT) technology is a relatively new technology that comprises a photovoltaic (PV) panel coupled with a thermal collector to convert solar radiation into electricity and thermal energy simultaneously. Since cell temperature affects the electrical performance of PV panels, coupling a thermal collector with a PV panel contributes to extracting the heat from the latter to improve its performance. In order to ensure a sufficient temperature difference between the PV cells and the working fluid temperature entering the thermal collector, the circulated water has to reject the heat that has been removed from the PV cells into a relatively colder environment. Borehole thermal energy storage (BTES), which is located underground, often serves as this relatively colder environment due to the stability of underground temperatures, which are usually lower than the working cell temperature. Use of BTES is especially beneficial in summer, when the degradation in cells efficiency is highest. In this thesis, the electrical, thermal, and economic performances of a PVT system are evaluated for three types of buildings -- residential, small office, and secondary school -- in two different climates in the United States, one of which is hot and the other is cold. For each case, two different scenarios are considered. In the first, a PVT system is coupled with BTES, and a ground-coupled heat pump (GCHP) is in use. In the second, a PVT system is coupled with BTES and no GCHP is in use. Each scenarios' GCHP performance is assessed as well. Both the PVT collectors and GCHP performances are evaluated over short and long-term to study the effect of continued ground heat imbalance on both technologies.

Committee: Andrew Chiasson Ph.D. (Committee Chair); Youssef Raffoul Ph.D. (Committee Member); Robert Gilbert Ph.D. (Committee Member) Subjects: Energy; Engineering; Mechanical Engineering

Master of Science in Renewable and Clean Energy Engineering (MSRCE), Wright State University, 2016, Renewable and Clean Energy

Most applications of flat plate, low-temperature solar thermal panels are for water heating, such as producing domestic hot water or raising the temperature of swimming pools. This is reasonable given that the large masses of water present in these systems inherently provide built-in thermal energy storage so that a separate energy storage tank does not have to be purchased. For a space heating system, extra thermal energy storage generally has to be purchased and is a detriment to the economics of these systems. Despite the economic drawbacks of solar thermal space heating, this thesis focuses on the size of thermal systems required to heat an average size home in Minneapolis, MN and Dayton, OH. For these two locations and for a standard test case, this thesis studies the effect of solar panel size and orientation, heat exchanger size, and operation parameters including flow rates through the solar panels and heat exchanger. Liquid, flat plate collectors are one of the simplest methods for collecting solar energy. These panels are generally inexpensive and can have collection efficiencies above 50%. This makes solar thermal panels more efficient than solar photovoltaic panels, which generally have efficiencies less than 20%. Since the solar thermal panels chosen for study in this work heat a liquid with the sun's energy and the fluid being heated in the building is air, a heat exchanger has to be included in the model. Lastly, because solar thermal systems are inherently unsteady, thermal energy storage must be included in the model. These components of a solar thermal space heating system are modeled by writing and adding routines to the Wright State developed simulation program called Solar_PVHFC. Solar_PVHFC is a simulation program which models solar photovoltaic panels coupled with fuel cells and hydrogen storage tanks. Because of this work, Solar_PVHFC is now capable of modeling a solar thermal system. The advantage of coupling this solar thermal work to So (open full item for complete abstract)

Committee: James Menart Ph.D. (Advisor); Allen Jackson Ph.D. (Committee Member); Amir Farajian Ph.D. (Committee Member) Subjects: Mechanical Engineering