Influence of local climate on the tilt and orientation angles in fixed flat surfaces to maximize the capture of solar irradiation : A case study in Cuenca-Ecuador

Solar energy use is spreading rapidly in the world. Determining adequate tilt and orientation angles of flat panels represent environmental, economic and energy benefits. In this study, the influence of local climate on the optimal fixed flat surfaces position is analyzed to maximize the capture of solar irradiation. Five mathematical models are used to estimate the total radiation received by a flat surface. These models use meteorological variables such as: global, direct, diffuse and reflected radiation, as well as incidence angles of the solar radiation for each of the 8760 hours of a year. The data were taken from 2 meteorological stations located in Cuenca-Ecuador city (2.88 ° S, 78.99W). The five used models: diffuse isotropic, Lui & Jordan, Klucher, Temps & Coulson, and Perez et al., concur in the results. The authors recommend in Cuenca-Ecuador, that the flat solar panels must be oriented 35 ° with respect to the North (NNE) and inclined 15° with respect to the horizontal. The obtained results suggest that, in areas close to the equator, the local climate influence is not dramatic. However, a further analysis ensures greater energy capture, so the tilt and orientation angles should not be established only with the geographical position information.