Prediction of Solar Irradiance and Illuminance Using Rest2 Model
Abstract
In this study, an analysis of the predictions based on the high-performance solar radiation REST2 model is presented. REST2 (Reference Evaluation of Solar Transmittance, 2 bands) is a two-band model developed by Gueymard to predict cloudless-sky broadband solar radiation. Model estimations of solar irradiance and illuminance are compared with experimental data. Data used in this study are obtained from a solar radiometric station sited at the Low Atmospheric Research Center, C.I.B.A., at Valladolid (Spain).Predictions for different time of the day and different periods along the year are analyzed. In summer time where the radiation is high, the predicted and measured values practically coincide while more deviation occurs when the radiation is low. RMSE values about 9% are obtained for both type of magnitudes, radiance and illuminance.