Increasing the Temporal Resolution of Direct Normal Solar Irradiance Series in a Desert Location

Abstract

Abstract The knowledge of the high-frequency temporal evolution of Direct Normal solar Irradiance (DNI) reaching the ground is a key parameter in the design and operation of Concentrating Solar Thermal Power (CSTP) plants, as instantaneous flickering nature of DNI can affect power system operations in several ways. In this study, a methodology to increase temporal resolution has been applied to increase the frequency of DNI series from 1-hour to 1-minute. This methodology is based in the nondimensionalization of the daily DNI curve by the clear-day envelope approach and uses the solar radiation data obtained in the one-year measurement campaign to characterize the DNI high frequency dynamics at a given site. The evaluation of the method with 2 years of ground measured data in a desert location have resulted in KSI (%) (Kolmogorov–Smirnov test Integral parameter) and normalized root mean square deviation values below 23% and 15% respectively for each month analyzed, with negligible mean bias, demonstrating the accuracy of the methodology.