PERFORMANCE EVALUATION OF CORRELATIONS TO ESTIMATE THE DIFFUSE COMPONENT FROM GLOBAL IRRADIANCE USING EXPERIMENTAL DATA FROM SONDA STATIONS IN BRAZIL

Alessandro Miranda de Freitas¹; Willian Mendes Ferreira¹; Rodrigo Figueiredo Abdo¹; Matheus Pereira Porto¹

¹ Universidade Federal de Minas Gerais

doi:10.20906/CPS/COB-2015-0717

Resumo

This work presents a discussion on the accuracy of the literature correlations to estimate diffuse irradiance from global irradiance, using experimental data set from SONDA stations in Brazil. Monitoring stations to measure direct and diffuse irradiance separately are costly, and for this reason many researchers have used correlations to estimate them indirectly from global irradiance measurements. Despite the fact that these correlations were conceived in most part for Europe and North America, authors have been keeping using them for other locations, as South America for example. Results have shown that literature correlations can estimate with good accuracy the diffuse fraction, for the data set used in this work. Additionally, we suggest more accurate correlations, based on local data set.

Palavras-chave: solar energy; solar irradiation; fraction diffuse; global irradiance; correlations