Abstract:

 Based on the monthly sunshine percentage and solar radiation data from 8 solar radiation stations surrounding Hebei province, the empirical coefficients of a and b in the climatic formula of total solar radiation were calculated by a least-squares method. These coefficients were then obtained for 142 stations in the whole province using methods of a latitude partition and an inverse distance weighted interpolation. The total solar radiations at four solar radiation observational stations were calculated using the above empirical coefficients and the results were compared with the observation. The comparisons have shown that the accuracies of the two methods are similar. However, the annual total solar radiation calculated using the latitude partition method is closer to the observation. Thus, this method is recommended to use for estimating the total solar radiation in Hebei province.

Key words: Total solar radiation, Empirical coefficient, Sunshine percentage