Detection of Cloudiness Periods and Characterization of Global Horizontal Irradiance in Argentina

ANABELA LUSI; FACUNDO ORTE; RAÚL D'ELIA; ELIAN WOLFRAM

Thessaloniki

Simposio; International Radiation Symposium; 2022

In the last decade, solar generation technologies have experienced strong energy market growth. A key issue in integrating solar power into the grid is the study of the short-term irradiance due to cloudiness, which can lead a large drop in solar generation in a few minutes (Yhingao, 2013). Ground-based monitoring is the most reliable technique for obtaining surface solar irradiance and allows to record it on a punctual location with higher frequency than satellite measurements, which enables the analyze of short-term solar irradiance variability. Argentina has developed the ground-based solar radiation network ?Saver-Net? (http://www.savernet-satreps.org/en), which account with 8 stations along the country covering a latitudinal range from ~26 to ~52°S (Orte, 2021). In this work, we implemented a method which uses only measured global horizontal irradiance (GHI) and a clear-sky model (Iqbal, 1983) for automated detection of cloudy periods and their characterization in Argentina. Different criteria (Reno, 2012) are used to determine the cloudy periods following thresholds values for each characteristic according to the behavior of measurements of solar irradiance respect to the clear-sky model. One of them is the line length, which calculate the length of the sequence of line segments connecting the points of one-minute GHI times series. The characterization of the GHI variability is helpful to evaluate potential solar powered sites.