Estimation of clear sky global solar radiation in Algeria

The paper presents the evaluation of performance of three models at three sites for estimating instantaneous clear-sky global solar radiation on a horizontal surface in Algeria. Additionally, recommend it to be used for estimating solar radiation at many locations in similar climates where radiometric measurements are not available and which might be helpful in the selection of the most suitable locations for solar power installations. The results in general exhibit that for global radiation, the daily correlation coefficient is higher than 0.99, whereas the mean absolute percentage error is less than 5%. The daily mean bias error ranges between -3 and +3%. The daily root mean square error is less than 7%. These results represent a precision that indicates that Atwater & Ball and Bird & Hulstrom models can be used successfully to predict solar radiation over three stations in the studied sites.