Abstract:

Based on the observed solar radiation data at 7 stations from 1961 to 2010 in Hebei province, a relatively accurate empirical formula on direct solar radiation was obtained. The temporal and spatial distribution of solar radiation was analyzed in Heibei province. The results indicate that the total annual solar radiation is in a decreasing trend, and the relatively higher and lower decreasing amplitudes are 25% in Shijiazhuang and 11% in Tangshan. The spatial variation of the horizontal direct solar radiation in Hebei province in recent 50 years is quite different. The area with the value less than 2540 MJ·m^-2  is mainly in the southern Xingtai, while the that with the value more than 3510 MJ·m^-2 is in the northwestern Zhangjiakou. The values of solar radiation are between 2540-3300 MJ·m^-2 in most areas of Hebei province. The potential ability for the development and utilization of solar energy resources is great in the dam area of Zhangjiakou in Hebei province.

Key words:  Sunshine percentage, Empirical coefficient, Correlation coefficient