ArticleSolar radiation incident upon slopes of different orientations
Abstract
By means of a pyranometer oriented at various tilt angles and azimuth angles with respect to the Sun, measurements of the direct and diffuse solar flux incident on slopes of various orientations have been made for clear sky conditions. The resulting data have been used to evaluate the validity of the solar flux model of Robinson[1] and to introduce certain modifications of that model to achieve better agreement of computations with measurements. It is concluded that the modified model yields significantly better results than the original for slopes oriented in the azimuth of the Sun, but results are comparable for other azimuthal orientations of the slope. The accuracy attainable by this modeling approach is considered sufficient for many practical applications.
Resumen
Por medio de piranómetros orientados en varios ángulos de inclinación y azimutales respecto al Sol, han sido hechas mediciones del flujo solar incidente directo y difuso para dias con condiciones de cielo claro. Los resultados de los datos han sido usados para evaluar la validez del modelo de flujo solar de Robinson[1] y para insertar ciertas modificaciones al modelo a fin de obtener una mejor aproximación entre los cómputos y las mediciones. Se concluye que el modelo modificado da resultados significativamente mejores que el original para inclinaciones orientadas en el azimut del Sol, pero los resultados son comparables para otras orientaciones azimutales de la inclinación. La exactitud obtenida por este modelo es considerada suficiente para muchas aplicaciones prácticas.
Résumé
Au moyen d'un pyranomètre incliné selon diverses orientations d'angles élévations et d'angles azimutes par rapport au soleil, on a effectué des mesures en ciel clair, sur l'incidence du faisceau solaire direct et diffus sur des pentes d'orientations diverses. On a utilisé les données qui en ont resulté pour évaluer la validité du faisceau solaire et modèle Robinson[1] et pour introduire certaines modifications de ce modèle afin de réussir une meilleur harmonie de la mise sur ordinateurs de ces measures. On en a conclu que le modèle modifié donne de toute évidence de meilleurs résultats que l'original appliquéà des pentes orientées vers l'azimut solaire, mais que les résultats sont comparables pour les autres orientations azimutales de la pente. L'exactitude atteinte par cette approche du modèle peut être considérée comme suffisante pour beaucoup d'applications pratiques.
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