Estimativas da radiação difusa horária incidente em superfícies inclinadas com base na transmissividade atmosférica

• Autor(a) principal: Souza, Adilson Pacheco de
• Data de Publicação: 2012
• Outros Autores: Escobedo, João Francisco [UNESP], Pai, Alexandre Dal, Gomes, Eduardo Nardini [UNESP]
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://rv.ifgoiano.edu.br/periodicos/index.php/gst/article/view/541; http://hdl.handle.net/11449/137487
• topic: Solar radiation; Radiometric fractions; Statistical index; Radiação solar; Frações radiométricas; Indicativos estatísticos

Evaluated statistical equations estimates (based on radiometric fractions) of the hourly diffuse radiation incident on inclined surfaces for the North to 12.85, 22.85 and 32.85°, the climate and geographical conditions of Botucatu, SP. The database was generated from April/1998 to December/2007, with measures in the three tilted surfaces in different periods, but concomitant to the horizontal plane. In the validation of the equations were used indicative statistics MBE (mean absolute error), RMSE (square root mean square error) and index adjustment (d) for three inclinations and conditions of sky coverage. The increased angle of inclination of the surface led to increased scattering of hourly values for the coefficient of atmospheric transmissivity of diffuse radiation for inclined and horizontal surfaces. Estimates of diffuse radiation on the basis of hourly tilted horizontal global radiation occur for quadratic polynomial models, which adjust K'Dβ maximum values of between 0.14 and 0.30 for winter and summer when KTH varies between 0.40 and 0.66, indicating that energy, the highest values of diffuse radiation occur in partly cloudy sky conditions and / or partially open. The increase in atmospheric transmissivity decreases the performance of annual and monthly equations at all inclinations.