CLEARNESS-BASED SKY TAXONOMY AND PREDICTIONS FOR TWO DIFFERENT LOCATIONS

This article presents a taxonomical analysis of the sky conditions, during 2012, for two different sites: the Joint Research Centre site in Ispra (Italy, European Solar Test Installation laboratories) and the site of Brookhaven National Laboratories in Upton (NY – USA). The key parameter is the sky clearness index kT, a dimensionless ratio of the global horizontal irradiance. In the first part, a taxonomical description using daily values of kT is presented, giving a general overview of the sky conditions during the year. In the second part the analysis is performed using short-term averages of the clearness index; remarkable properties of the statistical functions are highlighted and reinforced by using a fuzzy logic method, to extract time independent and site independent subsets. In the third part, a statistical analysis of the clouds intercepting the Sun’s trajectory is given, and finally, in the fourth part, some time-dependent correlations between the irradiance and other meteorological variables are studied.

PAVANELLO Diego;  ZAAIMAN Willem;  COLLI Alessandra;  HEISER John;  SMITH Scott; 

2014-01-27

WIP Munich

JRC84905

3-936338-33-7,   

http://www.eupvsec-proceedings.com/proceedings?paper=22584,    https://publications.jrc.ec.europa.eu/repository/handle/JRC84905,   

10.4229/28thEUPVSEC2013-5AO.9.5,