Solar beam radiation modeling for design and simulation of V-Trough photovoltaic applications
Fecha
2017
Autores
Arias Rosales, Andrés
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Editor
Universidad EAFIT
Resumen
Photovoltaic V-Troughs use simple and low-cost non-imaging optics, namely flat mirrors, to increase the solar harvesting area by concentrating the solar rays towards the photovoltaic surface -- Combined with stepped manual tracking, these devices can boost the performance of regular solar cells for residential and personalized scenarios in developing countries -- The geometrical set-up of a V-Trough, related to its length and angular parameters, conditions the optical phenomena that occur as the solar beam radiation dynamically interacts with the surfaces of the device -- These phenomena, such as shadows and consecutive reflections, determine the solar radiation that is effectively concentrated towards the photovoltaic area -- To support the design and simulation of such devices, this research project proposes a theoretical model of their effective concentration, seeking a high flexibility in the geometrical inputs, a detailed output of the optical phenomena involved and a low computational demand -- The model is based on the geometrical optics of beam solar radiation and it was experimentally validated in a statistical comparison against experimental measurements performed in a laser testing platform -- Based on the model, several design performance indicators were established: i) Ce (the average effective concentration); ii) Cost (the cost of materials); iii) Tsp (the space required) -- Moreover, from the integration of these indicators in proportional comparisons, three multi-objective indices were proposed: a) ICOE (Ce versus Cost); b) MICOE (Ce versus Cost and Ce versus Tsp combined); c) MDICOE (the same comparison as the previous one but also including the discretization effects related to the solar cells) – As tools for supporting the V-Trough set-up definition process, an interactive software and a series of genetic algorithms were developed based on these indicators and indices and the modeling framework developed -- The proposed software, named “VTDesign”, allows a V-Trough designer to iterate and compare diverse design alternatives in real-time by means of a visualization of the optical performance, representations of the geometrical set-ups and a cost-effectiveness analysis -- Among the genetic algorithms studied, a new genetic algorithm, named “GA-WA” (Genetic Algorithm - Weibull Arias), was proposed -- This tool uses heuristic processes, based on biomimicry and Weibull probability distributions, in order to optimize the indicators and indices as fitness/objective functions -- The intuition and the more holistic exploration of a trained engineer with VTDesign can be complemented with the broader and less biased evolutionary optimization of GAWA -- In a design case study, both VTDesign and GA-WA were implemented and found to be effective in the indices improvement, as well as efficient and flexible tools in the problem of defining the set-up of a solar V-Trough in a given personalized scenario