A Study on Aspect Ratio Optimization of Flat-Plate Solar Collector Arrays in Winter Months

A calculation model to optimize aspect ratios of a large scale solar collector array installed on the limited horizontal roofs has been developed. The relations between the average daily solar radiation collection on the collector array and the aspect ratio have been studied. The results show that there is an optimum aspect ratio to maximize the solar energy collection on the collector arrays. The optimum aspect ratios of the collector array covering a floor area of 1000 m2, 500 m2, 200 m2 and 100 m2 for Beijing are 10/1, 5/1, 5/1 and 3/1, respectively. For the sake of convenient applications, the optimum aspect ratios of five types of collector arrays with different floor area used in 13 cities in China are given.