Authors: Isaac Moradi Richard Mueller Richard Perez
Publish Date: 2013/08/09
Volume: 116, Issue: 3-4, Pages: 661-669
Abstract
Solar radiation is an important variable for studies related to solar energy applications meteorology climatology hydrology and agricultural meteorology However solar radiation is not routinely measured at meteorological stations therefore it is often required to estimate it using other techniques such as retrieving from satellite data or estimating using other geophysical variables Over the years many models have been developed to estimate solar radiation from other geophysical variables such as temperature rainfall and sunshine duration The aim of this study was to evaluate six of these models using data measured at four independent worldwide networks The dataset included 13 stations from Australia 25 stations from Germany 12 stations from Saudi Arabia and 48 stations from the USA The models require either sunshine duration hours Ångstrom or daily range of air temperature Bristow and Campbell Donatelli and Bellocchi Donatelli and Campbell Hargreaves and Hargreaves and Samani as input According to the statistical parameters Ångstrom and Bristow and Campbell indicated a better performance than the other models The bias and root mean square error for the Ångstrom model were less than 025 MJ m2 day−1 and 225 MJ m2 day−1 respectively and the correlation coefficient was always greater than 95 Statistical analysis using Student’s t test indicated that the residuals for Ångstrom Bristow and Campbell Hargreaves and Hargreaves and Samani are not statistically significant at the 5 level In other words the estimated values by these models are statistically consistent with the measured data Overall given the simplicity and performance the Ångstrom model is the best choice for estimating solar radiation when sunshine duration measurements are available otherwise Bristow and Campbell can be used to estimate solar radiation using daily range of air temperatureThanks to Stephen Wilcox NREL the USA for providing discussion on SERI QC Package and Lesley Rowland BOM Australia for kindly providing information about the Australian data Data from Australia Saudi Arabia and the USA were provided free of charge by the Australian Bureau of Meteorology BOM the US National Renewable Energy Laboratory NREL and the US Solar and Meteorological Surface Observation Network SAMSON database respectively
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