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Overcoming Fundamental Barriers In Photovoltaic And Terahertz Generation, Chao Zhou
Overcoming Fundamental Barriers In Photovoltaic And Terahertz Generation, Chao Zhou
Open Access Theses
Several fundamental barriers limit the performance of opto-electronic conversion processes below 100%. Two specific examples of current technological interest include photovoltaic conversion of sunlight into electricity (i.e., solar cells), and terahertz generation from optical sources. In particular, solar cells are limited not only by the Carnot limit associated with the second law (approximately 86% at room temperature), but also by radiative recombination, non-reciprocity, carrier thermalization, and sub-bandgap losses. In the case of terahertz generation, the typical process of difference frequency generation relies on two input optical waves with only a small difference between them to generate the desired output; however, …
Comparative Lca Of Stand-Alone Power Systems Applied To Remote Cell Towers, Eduardo Olmeda Noguera
Comparative Lca Of Stand-Alone Power Systems Applied To Remote Cell Towers, Eduardo Olmeda Noguera
Open Access Theses
Remote cell towers need on-site power generation or stand-alone power systems for operation and, traditionally, diesel electric generators have been used as backup power systems in combination with renewable energies. Currently, Polymer Electrolyte Membrane Fuel Cells (PEMFC's) are emerging as substitutes for the diesel electric generator, because of their reliability, high-energy conversion efficiency and zero emissions while operating.^ However, very few studies have compared the environmental impact of these two technologies, especially on remote cell tower applications. As PEMFC's have no emissions while operating, concerns about their environmental impact surge because of the use of rare and high processed materials, …