Comparison of NASA-POWER solar radiation data with ground-based measurements in the south of South America

Accurate information of solar radiation from satellites is crucial for many applications, mainly in regions with lack of ground-based measurements. In this sense, comparison with ground-based measurement is necessary to ensure the reliability of the information. In this work, the daily global solar irradiation data from NASA's Prediction of Worldwide Energy Resources (NASA-POWER; power.larc.nasa.gov) were compared with ground-based measurements in the 8 stations of the Saver-Net solar irradiance network (http://www.savernet-satreps.org/en) installed in the south of South America. A linear regression analysis was performed to analyze the agreement between satellite data and ground-based measurements. The coefficient of determination shows very good correspondence with a mean value of 0.95. The mean absolute error (0.63 kWh/m(2)/d) and the root mean squared error (0.48 kWh/m(2)/d) reflect a low difference.