Study of solar radiation data for Hong Kong

In 1991, a measuring station was set up at City Polytechnic of Hong Kong to measure hourly global and diffuse solar radiation. This paper describes the measurements made from 1991 to 1993 and some of the findings from the data observed. The frequency distribution and magnitude of the average solar radiation values are computed and examined. Symmetry of the solar radiation around solar noon and seasonal variations are noted and discussed. Monthly average daily clearness index (K-t) and diffuse fraction (K) for all months are determined, and their implications for clear and cloudy days estimation are remarked. Theoretical models to predict hourly radiation from daily values have been tested, and it has been found that the models are applicable to Hong Kong.